OTGH THE LAI D SCHOOL G T?' 'h'T AGKSON &DAUGHE ■"^ -v'^'iy rt-\ Class _jl^il Book - J/^ Copyright}!^ COPYRIGHT DEPOSIT. HYBRID CARNATION. A. SCOTT, FEMALE PARENT. C. HYBRID. B. MCGOWAN. MALE PARENT. AGRICULTURE Through the Laboratory and School Garden. A MANUAL AND TEXT-BOOK OF ELE- MENTARY AGRICULTURE FOR SCHOOLS. C. R. JACKSON Introducer of Practical Agriculture and School Gardening into the State Normal School, Kirks-ville, Alo. MRS. L. S. DAUGHERTY Assistant in Zoology, State Normal School, Kirks-ville, AIo. Give men their gold, and knaves their power, Let fortune's bubbles rise and fall, Who plows a field, or trains a flower, Or plants a tree is more than all; For he who blesses, most is blessed. And God and man will own his worth Who seeks to leave as his bequest An added beauty to the earth." NEW YORK ORANGE JUDD COMPANY 1908 fuBHAK'Y of OONdRES? Iwu iiODies ne(;eiv«<< SEP 4 )a08 OLaS» CX XAC. Nu. ■2_- I S i> "1 •% OOPY a. Copyright, 1905, iqo8 By ORANGE JUDD COMPANY. INTRODUCTION. From the growth and drift of public sentiment it is evident that education in Agriculture will soon be offered in all good elementary schools of our country. This, from the nature of the case, seems unavoidable, because such instruc- tion is essential both for utility and for culture. It is an essential utility, because it is the only means of furnishing adequate conceptions of the one fundamental occupation of mankind upon which all other occupations depend. For the masses it is an essential basis of true culture and refinement, as illustrated in its ear- liest fruitage, which is the adornment of homes through improved lawns, shade-trees, walks, driveways, gardens, flowers, etc., thereby open- ing the avenues to consciousness and revealing in the most pleasing way the beauty world all around us. This volume is unique. It is not the product of its authors' imaginations. No one designed it to exploit a theory or a person. It is an out- line of work done — done by ordinary people under ordinary conditions. The Agricultural Laboratory and the School Garden of the Kirksville Normal School have yi INTRODUCTION. grown from very small beginnings. They are now the objects of keen interest in many parts of the United States. Their purpose at all times has been to prepare teachers to give prac- tical and definite agricultural instruction in public schools of all kinds. John R. Kirk. PREFACE. The preparation of this book was undertaken, primarily, that the classes in Agriculture of the State Normal School of Kirksville, Missouri, miofht have in one book the directions for all laboratory experiments and exercises, and such information as would enable them to under- stand the results of these experiments. We believe that the book will meet the needs of most schools where Agriculture is taught or should be taught. It has been deemed necessary to embody in the text such facts and principles of Geology and Botany as are absolutely essential to the understanding of agricultural principles and processes. The work is intended to cover one year's time, but any part of it may be omitted if the necessary materials cannot be obtained. The time to be spent upon each phase of the work must be determined by the class, the materials accessible, and the teacher. It is neither pedagogical nor scientific to tell a student what he can find out for himself. It takes away both the incentive and the necessity for experimental work to foretell the result. Viii PREFACE. Our aim has been to present actual experimental work in every phase of the subject possible, and to state the directions for such work so that the student can perform it independently of the teacher, and to state them in such a way that the results will not be suggested by these direc- tions. One must perform the experiment to ascertain the result. Any energetic teacher can, by carefully going over the work in advance, working out the ex- periments himself and reading the references, be able to do creditable class work if he is willing to " dig," but it is useless for any one else to undertake to be an agriculturist or to teach agriculture. Every available source has been drawn upon for the material used in this book, but the plan of presenting it is original, as well as most of the experiments and exercises, and many practi- cal ideas gained from experience in teaching. We wish to express our grateful appreciation to all those who have so kindly helped us by reviewing the manuscript or by loaning us illus- trations. The following persons from the United States Department of Agriculture at Washington have been very helpful: The manuscript was examined by B. T. Galloway, Chief of the Division of Plant Industry; W. J. Spillman, Agrostologist ; A. F. Woods, Pathologist and Physiologist ; PREFACE. ix and M. B. Waite, Assistant Pathologist. The chapters on " Propagation," " Improvement," and " Pruning " were read by L. C. Corbett, Horticulturist, and the one on *' Enemies of Plants " by the Entomologist, Mr. Wilcox. " Ornamentation of School and Home Grounds" was read by Mr. Crosby. The chap- ter on " Enemies of Plants " was also read by H. Garman, State Entomologist of Kentucky. The first half of the book was examined also by Professor Mumford, Acting Director of Missouri Experiment Station, and by W. T. Carrington, State Superintendent of Schools. The second half was examined by J. C. Whitten, Horticul- turist, Missouri Experiment Station. The first chapter was criticised by C. F. Marbut, Assist- ant Professor of Geology, University of Missouri. The second half of the manuscript was ex- amined by Dr. L. S. Daugherty, of the State Normal School, Kirksville, Missouri. The entire manuscript was submitted to H. J. Waters, Su- perintendent of Agriculture, World's Fair, St. Louis, Missouri. The chapter on Milk and Its Care was written by C. H. Eckels, of the Mis- souri State University. We are indebted to the following persons and Experiment Stations for illustrations : Ex- periment Stations of Minnesota, West Virginia, Rhode Island, New Hampshire, Kansas, Mis- souri, Ithaca, New York, New Jersey, Texas, X PREFACE. and that of Hampton Institute (Va.) ; to the United States Department of Agriculture ; the United States Geological Survey ; Ladies Home Jotirnal ; OrdiUgit Judd Co.; Waugh's "Land- scape Gardening" ; D. C. Heath & Co. ; Leg- gett & Brother; The Deming Co., and others mentioned with the figures. The Authors. KiRKSVILLE, Mo., 1903. To the earlier edition has been added a chap- ter on " Farm Animals" by E. A. Trowbridge, of the Missouri Experiment Station. Several figures have been inserted and additional text has been written on the School Garden. A number of changes and additions have been made in other chapters. The whole book has been gone over critically and parts which have proved impracticable or doubtful have been omitted. The Authors, July ist, 1908. CONTENTS. CHAPTER. PAGE. I. Nature and Formation of Soils .... 3 II. Classification and Physical Properties OF Soils •. • • 43 III. Soil Moisture and Preparation of the Soil 59 I\'. The Soil as Related to Plants .... ']'/ \ . Leguminous Plants 109 W. Principles of Feeding 131 VII. Rotation of Crops i53 VIII. Milk and Its Care 163 IX. Propagation of Plants 201 X. Improvement OF Plants 245 XI. Pruning of Plants 271 XII. Enemies of Plants 289 XIII. Ornamentation of School and Home Grounds 349 XIV. Farm Animals 393 General References : Weeds 437 Forest Trees of America 437 Agricultural Publications : Publications of United States Department of Agriculture 438 Publications of State Experiment Stations . 438 Agricultural Experiment Stations 439 Publishing Houses 441 Glossary 442 Index 445 xi ILLUSTRATIONS, PAGE. Red and White Carnations with Hybrid Produced by Crossing Frontispiece. Wind-bk)wn Sand-drifts 8 Planting Beach Grass to Hold the Sand at Cape Cod, Mass. 8 Apparatus for Experiment i lo Deposition of Material Upon Slacking of Stream ... i6 Shales "Creeping" Under the Action of Frost .... 20 Formation of Glaciers 21 Action of Glacier Drifts 23 Mechanical Action of Rain 26 Roots of Forest Trees Opening a Rocky Subsoil ... 29 Vegetation Protecting the Soil 30 How the Farm is Retained 37 View of an Irrigating Ditch When Made 39 View of the Same Ditch Ten Years Later 39 Fifth Grade Children Collecting Different Kinds of Soil 47 Temperature Curves of a Humous St)il 50 Apparatus for Experiment 5 5^ Apparatus for Experiment 6 53 Apparatus for Experiment 7 54 Apparatus for Experiment 9 61 Apparatus for Experiment 13 67 A Good Plow 69 A Plank Harrow 70 A Rolling Cutter Harrow /O A Spring-toothed Harrow 71 A Coulter-toothed Harrow /i To Show the Effect of Deep and Shallow Plowing . . 73 Showing Effect of Nitrate 80 Tubercles on Velvet Bean Produced by Inoculation . . 83 A Covered Barn-yard , . . . . 103 Comparison of Vetch Plants iii Roots of Yellow Soy-bean 112 Alfalfa Plant "5 The Cow-pea 124 The Soy-bean 125 xii ILLUSTRATIONS. xiii PAGE. Round Silo, Missouri Agricultural College Farm . . . 149 Wheat Grown After Cow-peas 155 Pure and Impure Milk Highly Magnified 165 Pasteurizing Apparatus 167 A Guernsey Cow — Charmante of the Gron 14442 . . . 172 A Jersey Cow — Imp. Jersey Venture 122508 172 An Ayrshire Cow — Viola Drummond 174 A Holstein Cow . , 174 Glassware for Babcock Tester 178 Hand-power Babcock Tester 179 Cooley Creamer . 185 A Modern Hand-power Cream Separator 187 Barrel Churn 191 Farm Dairy Butter-worker 195 Students Molding and Wrapping Butter 197 Catalpa Tree 203 Seedlings of Indian Corn 210 Red Fir (elevation, 9,000 feet) 213 Red Fir (elevation, 4,700 feet) 213 Rooted Tips of a Seedling Raspberry Cane 218 Leaf Cutting— Whole Leaf 219 Leaf Cutting — Part of Leaf 221 Leaf Cutting of Saiisez'icria scylanica 221 Tip Cutting of a Chrysanthemum 222 Cutting of Heliotrope 222 Cutting of Oleander Rooting in Water 223 Stem Cutting of Umbrella-plant Rooting in Water . . . 223 Removing a Plant from a Pot 224 The Plant Removed from the Pot 224 Children Potting Plants , , 226 Twig of White Elm , , 227 Position of Hard-wood Cutting in Soil 228 Rooted Grape Cutting 228 Grape Cutting 229 Cutting of Blackberry Root 229 The Way to Remove a Bud 230 One-year-old Peach Seedlings 231 Stages in Budding 232 One-year-old Piece-root Graft 23s Steps in Root-grafting 234 Dormant Apple Twig 235 xiv ILLUSTRATIONS. PAGE. Steps ill Stem-grafting 236 Mound Layering 239 Variation in Grains of Corn 246 Improvement of Corn by Selection 251 Plant Rosettes 255 Potato Plant 257 Modification of Cosmos by Pruning 258 The Parts of a Flower 262 Orange Bud and Blossoms 263 Orange Flower 264 Nearly Mature Hybrid Orange 264 Cosmos Flowers 266 Diagram Showing Method of Selecting and Improving Seed 267 Diagrammatic Cross-Section of a Basswood Stem Two Years Old 273 Improper and Proper Pruning 2"]}, Grass Growing in Cavity — Result of Improper Pruning . 275 Same Tree After Cavity Has Been Repaired 275 The Way to Remove a Large Limb 276 Where to Cut the New Growth 277 Apple-tree Headed Low 280 Trees Growing Close Together for Timber 281 Norway Maple 283 Net for Collecting Insects 291 Cyanide Bottle 292 Breeding-jar for Rearing Insects 292 Collecting Insects 294 A Bucket Spray 304 The Bordeaux Nozzle 305 Hand Spray . 305 Meadow-lark 308 House Wren 309 Four Common Seed-eating Birds 311 Four Common Weeds, the Seeds of which are Eaten by Birds 313 Weed Seeds Commonly Eaten by Birds 314 "Look out!" 316 Anatis lypunctata. Say 318 Ladybug and Larvae Preying Upon Scale Insects Infest- ing a Pear 319 Epilachna corrupta 319 Chrysopa Species 320 ILLUSTRATIONS. xv PAGE. Ichucumon-tly Depositing an Egg within Cocoon . . . 321 Ants Milking Plant-lice 3^5 American Tent-caterpillar 3-6 Baltimore Oriole Attacking the Nest of the American Tent-caterpillar 2>^7 Forest Tent-cocoons in Apple Leaves 3-S Forest Tent-caterpillars Feeding Upon Elm Leaves . . 329 Codling-moth 330 Round-headed Apple-borer 2>2>Z Sapcrda Candida, Fab 334 Brown Rot 337 Black Rot 338 Grapes from Vineyard Affected with Black Rot .... 339 An Apple Attacked by Bitter-rot Fungus 340 Apple Scab 34i Agricultural Class, State Normal School, Kirksville, Mo. 348 A Country School-yard — Bare and Unattractive .... 350 The Same School-yard Improved by Plantings of Shrubbery 350 Fifth Grade Children Planting Their Garden 354 Fourth Grade Children Caring for the Lawn Around the School Garden 355 School Gardening — Agricultural Students 358 Roman Hyacinths ' . 360 Chinese Sacred Lily 361 Geometrical Designs 365 Natural Style 369 Trees Showing Kinds of Te.xture 371 American Elm 374 Ash 374 A Cool and Inviting Retreat 376 Ferns and Phlox 377 Mass of Shrubbery 378 Dogwood in Flower 381 Pansies 383 Shall the Children Pluck Flowers or Rattle Tin Cans in • the Back Yard? 384 Back-yard Screen 385 A Bouquet of Sweet Peas 386 A Small Lake, with Well-selected Plantings 388 "Artist Montrose" 405 Hackney Stallion "Sir Humphrey" 408 xvi ILLUSTRATIONS. PAGE. Percheron Stallion "Pink" 411 Pure-bred Aberdeen Angus Steer "Andy" 414 "University Daizie" 417 Red-polled Bull "Bounce" 420 Southdown Wether 421 Rambouillet Ram 422 Champion Poland China Barrow 427 Large Yorkshire Boar, "Holywell Royalty II." .... 429 Single-comb White Leghorn Cock 433 Barred Plymouth Rock Hen 433 Buff Cochin Cock 434 Light Brahmas 434 AGRICULTURE THROUGH THE LABORATORY AND SCHOOL GARDEN. OUTLINE OF CHAPTER I. NATURE AND FORMATION OF SOILS. ^.—SOURCES OF ENERGY. I. The Earth's Energy. II. The Sun's Energy. i5.— FACTORS OF SOIL FORMATION. I. The Atmosphere. *i. It Rfgulates the Temperature. 2. Movements of the Atmosphere. 3. Chemical Action. Experiment i. 4. Alternations of Heat and Cold. II. Water. 1. Chemical action. 2. Mechanical Action. Disintegrating., transporting, assorting. Experiment 2. (i) Rivers. Experiment 3. (2) Underground Streams. (3) Landslides. (4) Lakes. (5) The Ocean. (6) Frost. 2 AGRICULTURE. (7) Ice. (8) Snowslides. (9) Glaciers. (10) Icebergs. 3. Field Exercise No. i. III. Organic Life. 1. Plant Life. (i) Mechanical or Physical Effects (2) Chemical Effects. (3) Vegetable Accumulations. 2. Animal Life. (i) Disintegration. (2) Animal Accumulations. Calcareous Deposits. Siliceous Deposits. Phosphatic Deposits. 3. Environmental Changes. 4. Field Exercise No. 2. CHAPTER I. NATURE AND FORMATION OF SOILS. Soil is derived, primarily, from rock * in the broadest sense of the term. The cycle of tear- ing down in one place and building up in an- other has been constantly going on for ages, and is still going on to-day. It is to this cycle of changes, discussed in the following pages, that we owe the presence of the loose surface material of the earth (some places a few hun- dred feet in depth, and in some places entirely wanting) which makes it possible for plants and animals to live, and which loose material forms the basis of all soil. y^.— SOURCES OF ENERGY. The matter which constitutes the earth and atmosphere, though it cannot be destroyed, is constantly changing its form, under the action of existing forces. The soiu^ces of all these forces, or of our supply of energy, are the earth and the sun. I. The Earth's Energy. The earth's energy is from within, and some of its manifestations are the upheavals and dis- ruptions of the crust, and, greatest of all, the * " Any substance constituting a portion of the earth's crust ... is called a rock." — Leconte's Conupeitd of Geology, p. 17S. 3 4 AGRICULTURE. force of gravity, without which nothing could remain upon the surface of the earth, owing to the centrifugal force caused by the rotation of the earth. Other forms of energy are the molecular!^ forces of cohesion^ and adhesion,;^ and the atomic force of chemical affinity, all of which exist within the substances themselves, and act at insensible distances. II. The Sun's Energy. The great source from which we derive, either directly or indirectly, most of our energy is the sun. " The circulation of winds and waters, the changes of temperature, and the activities of living beings all depend upon the sun's energy," * without which there could be upon the surface of the earth no motion and no life. The sun's energy comes to us, it is believed, by means of waves in the ether of space. Some of these waves produce the various colors, or are what we might call light waves ; others are not perceptible to the human eye, but are heat waves ; still others are especially productive of chemical changes, as is manifested in photog- raphy. When the sunshine falls upon the soil a por- tion of it is absorbed, and the molecular motion + Terms thus marked (double dagger) throughout the book are found in the Glossary. * Scott's Geology, p. 29. NATURE AND FORMATION OF SOILS. 5 within the soil is increased, producing a certain amount of heat. This heat, when transmitted to the air, causes it to expand and thus become lighter, when the cooler and heavier air rushes in from the sides, forces it upward, and wind re- sults ; if transmitted to the water, the increase of the molecular motion of the water overcomes the force of cohesion, and evaporation ensues. As the vapor rises it gradually becomes cooled and condensed, and clouds composed of minute particles of water* are formed; these minute particles of water, after further cooling and condensing, are united by cohesion into drops, and are drawn back to the earth by the force of gravity, in the form of rain, snow, or hail. These few examples may serve to show how the sun's energy is transformed into a multitude of activities. ^.—FACTORS OF SOIL FORMATION. I. The Atmosphere. I. It Regulates the Tempei'atMre. — On winter nights the lower layer of air — especially if laden with dust and moisture — acts as a blanket in checking radiation of heat from the earth's surface. But, in the intense heat of summer, this lower layer of air would, through radiation * " Clouds formed at temperature above 32° consist of minute spherical drops of water 1-4000 to i-iooo of an inch in diameter; those formed below 32° consist of minute ice spicules which in- crease in size and become snow." — YiSi.vK's,' Meteorology,-^^. 159, 160. 6 AGRICULTURE. of heat from the earth, become unbearable for all living beings were it not for its currents, caused by the expansion of the heated air which renders it lighter and causes it to rise, while the cooler air above, being heavier, descends by the force of gravity."^' 2. Movements of the Atmosphere. — It is to these movements — due, primarily, to the coun- teraction of the sun's energy by the force of gravity — that we owe the formation of clouds and the condensation of their moisture ; the dis- tribution of gases to act upon the rock surface, or to be consumed by living beings; the circu- lation of air in the soil, so essential to plant life; the transportation of plant food and of seeds ; and the maintenance of the relative composition of the whole atmosphere. It is through these movements that the air travels to the sea and back again, bringing moisture for the thirsty life. The winds play an important part in the for- mation of soil : {a) in the disintegration of rocks, by pelting them with sand or rain, thus mechanically wearing them away by friction ; (^) by keeping them bare, so that they are ex- posed to other atmospheric forces ; (^) by stir- * " Professor Langley, after a long and careful experiment at the base and summit of Mount Whitney, California, concludes that had our earth no atmosphere its surface temperature under the equator at noon would be 328° F." — The Soil, King, p. 13. NATURE AND FORMATION OF SOILS. 7 ring up the ocean into waves and billows, which beat upon the rocks, carrying with them sand and pebbles, which grind each other into powder. On the sandy beach of the ocean and of the great lakes, and in the great sandy plains, or wherever the sand is loose and unprotected by vegetation, the wind becomes a potent factor (Figs. 1-2). Along the shore of Lake Michigan sand-dunes are destroying forests^ and often when the forests have been cut off, fertile farms are covered by these great accumulations of wind-blown sand. In conjunction with sand, the wind builds or destroys islands. The loess in China is a deposit of wind-blown soil. In the desert of Sahara and in our great western plains great blinding storms of dust and sand occur. The sand, too heavy to be lifted more than a few feet high, is rolled along and drifted in wave-like mounds, which change their shape and position with the changes in the direc- tion of the wind — just as the snow-drifts are formed in waves— and the particles are sucked up into the whirling air, and redeposited in a new place by the force of gravity as the motion subsides. One of our "blizzards" is a good il- lustration of a sand-storm, only the substance transported by the wind is snow instead of dust and sand. 3. Che7nical Action. — Another phase of atmos- pheric work is that of chemical action. Dry air FIG. I. — WIND-BLOWN SAND-DRIFTS. FIG. 2. — PLANTING BEACH GRASS TO HOLD THE SAND AT CAPE COD, MASS. NATURE AND FORMATION OF SOILS. 9 has little chemical effect, but moist air is very active. The oxygen, which is now known to combine with nearly every other element, seeks to unite with the minerals of the exposed rocks.* Iron, which in some form is contained by most rocks, unites readily with oxygen in the presence of moisture, forming rust, which stains, softens, and ultimately causes the disintegration of the rock. Carbon dioxide (COj), though present in a comparatively small quantity, is a powerful agent both in moist air and in rain-water. It acts upon the rocks, especially upon limestone, causing them to crumble away or to be entirely dissolved. Experiment i. — Before beginning to perform any experi- ment in this book, read over the entire directions for it, get necessary apparatus ready, and know what you are going to do a fid 7i>hy you are going to do it. Record your observations at the tifne they are made, not after leaving the laboratory. Throughout this book, wherever the word " ?tote " is used, it means to observe and record your observations or expla?iatio?is. {a) Break pieces of limestone, marble, or clam-shells into tiny bits, and place a small quantity in a wide- mouthed bottle. {b) Pour in small successive portions of dilute hydro- chloric acid (HCI). Note what takes place as the acid comes in contact with the stones or shells. Both the hydrochloric acid and the calcium carbonate of the stones or shells are decomposed, and calcium chloride * Gilbert and Brigham, Physical Geography, p. 78. 10 AGRICULTURE. (CaCl,), water (H^O),and the gas carbon dioxide (COJ are formed. (c) Now pass some of this gas, or carbon dioxide, from the bottle into the solution of clear lime-water (Fig. 3). (d) To prepare lime-water, dissolve common lime in pure water, let stand until clear, and carefully pour off the liquid, or pass it through a filter-paper. J What takes place when the carbon dioxide passes into the lime water? Allow the gas to continue to pass, and note the result. (e) Boil the liquid, and again note result. (/) Write up this experiment, stating the materials used, observations made, and what the experiment teaches, together with any further remarks or conclu- sions you may make concerning each step. When the carbon dioxide was first passed into the lime-water, a precipitate of calcium carbon- ate (CaCOj), or limestone, was formed. It continued to pass until there was no more calcium hydroxide, or lime- water, Ca(OH)2, to com- bine with it, when the carbon dioxide united with the water (H^O) to form carbonic acid (H2CO3). This acid at once acted upon the precipitate of calcium carbonate, form- ing a soluble bicarbonate of calcium, HjCa (COj)^, which is dissolved, and the liquid be- comes clear. The boiling drives out part of FIG. 3. — APPARATUS FOR EXPERIMENT I. NATURE AND FORMATION OF SOILS. H the carbon dioxide, and the calcium carbonate is again precipitated. Other substances of the air which bear impor- tant relations to agriculture are nitrogfen and its compounds, ammonia, nitrous and nitric acids, and ozone. 4. Alternations of Heat and Cold. — In dry, hot countries, rocks become excessively heated during the day and rapidly cooled at night. As the outer layer cools it contracts upon the hot and expanded interior, which tends to produce snapping and crumbling of the brittle min- erals. Thus we see the work of the atmosphere is constant ; it is universal ; it is not, however, uniform.''^ Both the rapidity and the extent of disintegration are dependent upon the differ- ences of climate in various latitudes and alti- tudes, the differences in the rock substances themselves, the differences of seasons and of the amount of precipitation, and upon the pres- ence or lack of protection from vegetation or soil. * The composition of the air varies greatly in different locali- ties, or under different conditions in the same localities; but, under ordinary conditions, its constituents in a given volume are, approximately: oxygen, 20.6 per cent.; nitrogen, 77.18 per cent. ; water vapor, 1.4 per cent.; carbon dioxide, .04 per cent. ; argon, .78 per cent. The water vapor and carbon dioxide are the most variable. And there is present a variable quantity of ammonia, nitrous and nitric acids — a very small fraction of i per cent, alto- gether. 12 AGRICULTURE. II. Water. Among the factors of soil formation none is greater than that of water in its various phases — as, rain, rill, river, lake, and sea ; frost, ice, avalanche, and glacier. I. Chemical Action. — In many of its forms water exerts a violent and stupendous force, but there is a silent and subtle force whose re- sults are often overlooked. It is the great sol- vent power of water. It absorbs both oxygen and carbon dioxide from the air, and these give it great chemical power in dissolving, or de- composing, rock substances."^* The simplest effects are the uniting of oxygen and of water with the minerals composing the rocks. But as the rain sinks into the ground it is provided with new weapons through the absorption of the humic acids and, possibly, of alkaline sub- stances. For this reason, many rocks disinte- grate more rapidly under ground than they do when exposed to the atmosphere. Calcium carbonate, or limestone, is the sub- stance dissolved or decomposed in the greatest quantity ; but magnesium carbonate (MgCOj), organic matter, silica (SiO^), and many other substances are held in solution by clear river water. (See " Field Exercise No. i," Part 2.) * " Perfectly pure water has very little effect, but perfectly pure water does not exist in nature." — Scott's Geology. NATURE AND FORMATION OF SOILS. 13 The amount of these dissolved materials — though far less than that produced by mechan- ical action — is astonishing. That carried into the Gulf of Mexico by the Mississippi River an- nually reaches over 112,000,000 tons — -not all derived from the river-bed, but taken up by the water from the time it falls in rain till it reaches the sea, whether it flows through the river and its branches, or whether it comes from springs or other underground sources. 2. Mechanical Action. — The mechanical action of water is threefold, (i) It disintegrates. (2) It transports. (3) It assorts. The mechanical action of rain is due to the friction produced by the drops in striking the rocks, and by the abrasion of solid particles as they are carried to lower levels. It forms into little rills and gullies, washing out and carrying with it as it goes all the loose material which it can hold in suspension (Fig. 8). The amount thus obtained depends partly upon the solubil- ity of the rock over which it flows (though even a granite would be slightly dissolved by ordinary rain-water), and partly upon the vio- lence of the precipitation, and the volume and velocity of the stream. The velocity is affected by several influences, but the greatest of them is the constant, never- failing action of gravity. Hence, the steeper the descent the greater the velocity. The 14 AGRICULTURE. power is supplied by the volume and velocity of the stream, but the work of abrasion is per- formed, for the most part, by the sand, pebbles, and rock fragments as they are rolled along. They cut down into the river-bed, wearing it deeper; they polish each other into rounded or flattened shapes, or grind each other into pow- der in their mad rush to the sea. The transpo7^ting power of running water varies as the sixth power of its velocity, so that if its velocity be doubled it can carry sixty-four times as much solid matter as before. Thus it is that a slight increase in the velocity will greatly increase the load of a stream if the ma- terials are obtainable, while the slightest de- crease in the velocity will cause a part of the load to be deposited. These river deposits are commonly in sheets or bars, but when the river suddenly enters a plain at the foot of a steep slope an alluvial fan is formed by the deposition of the sediment. According to the calculations of the United States government made many years ago, the Mississippi River transports to the gulf every year enough solid substance to make a column one mile square and 268 feet high — 200,000,000 tons. The student can find no better example of the carrying power of water than that of the roadside rills and gullies after a heavy rain. NATURE AND FORMATION OF SOILS. 15 Experiment 2. — (a) Weigh a glass fruit jar, and col- lect in it the clouded or muddy water — from a gullj' or stream, after a rain — and allow it to stand until clear. {/?) Weigh again; then carefully pour off the water, and weigh the sediment remaining in the jar. (c) Calculate the per cent, of sediment. ~ (i) Rivers. — When rivers overflow their banks the water loses its velocity, and a layer of sediment is deposited on either side of the stream. In the great rivers these flood-plains are broad fertile tracts of land very valuable for agriculture. Those of the Mississippi are many miles in width, but have to be protected by levees from the overflowing of the river. Where the river empties into the quiet waters of a lake or sea the velocity is checked and the stream deposits its load. As the stream slack- ens the heavier particles are dropped first, and so on, until in the quiet waters only the finest silt is carried. Hence it is that, on lake or sea- shore, we find the coarser materials thrown down first, and farther out the finer sands (Fig. 4). There is usually a pause after such deposition is made until a fresh supply of sediment is ob- tained. This allows the surface to assume a somewhat different arrangement. This surface forms the plane of contact for the next layer, and is called the "stratification plane." Experiment 3. — The assorting power of water may be illustrated by (a) placing a mixture of rock material of IG AGRICULTURE. various sizes — pebbles, sand, clay, and vegetable mould- in a candy-jar, and nearly filling the jar with water. (d) Now thoroughly stir the mixture, and allow it to stand until the water clarifies. (c) Observe the arrangement of the sediment. Where are the largest pebbles found ? Where the finest clay ? Of course the change here will be gradual, and FIG. 4 — DEPOSITION OF MATERIAL UPON SLACKING OF STREAM the layers will not be so distinct, as there was no time for the formation of the stratification^ plane between the depositions of different kinds of sediment. (2) Underground Streams. — Part of the water after a rain sinks into the ground. The natural breaks in the rock serve as channels which it may enlarge if the rock be soluble. NATURE AND FORMATION OF SOILS. 17 These underground streams perform various kinds of work, such as weakening rocks, dissolv- ing minerals, carving channels, rising in springs or in artesian wells, bringfing" mineral matter to the surface, and forming caves and making peculiar deposits in them. (3) Landslides are caused by the undermin- ing of masses of rock and soil by water, which produces a slippery surface of bed-rock, and makes it easy for gravity to move an enormous quantity of soil or rock down the declivity. (4) Lakes differ from oceans in being (usu- ally) above the sea-level; in size; and in the freshness of their waters, provided they have an outlet. Their chief movements are zuaves pro- duced by ivi'ids. These waves often erode the shore. They carry with them and distribute over the bottom of the lake the sediment brought by the rivers, thus making stratified rock. (5) The ocean, with its waves, tides, and cur- rents, which constantly beat upon the shore, plays an important role in this great drama. As we have seen, the material transported by the rivers may form deltas and bars, or be wide.y distributed, according to the strength of the tides and the power of the currents along the shore. More than one-half of the rocks have been laid down in the sea and then raised above it. ]8 AGRICULTURE. These deposits were not made out in the open sea, but near the shore in shallow w?.ter. Their thickness is accounted for by the theory that the ocean bottom was sinking g-radually, and fresh deposits were made above the preceding ones. In the open sea are found the deposits of very fine particles carried out by the rivers — on the continental slopes from the one hundred fathom line to the oceanic abysses — and they are known under the indefinite term of "mud." There are also volcanic deposits and great accu- mulations of organic remains. Every animal in the sea which has a shell or hard skeleton helps to make these deposits, but by far the greater part of them is made up of the shells of minute organisms''^ which live near the surface. The diatom ooze is composed of the siliceous re- mains of microscopic plants. (6) Frost. — Frozen water has done a great share of the work in this process of mantling the earth with loose material. Some rocks are more porous than others, though those appar- ently solid will, upon examination, be found to be crossed by joints which divide them into blocks. These are filled with minute crevices and pores, through which the water percolates even to the very center. Water, upon passing * Jordan and Kellogg's Animal Life, p. 18. Scott's Geology, pp. 176-180. NATURE AND FORMATION OF SOILS. 19 into a solid state, expands about one-eleventh of its original bulk. This expansion exerts an ir- resistible force, as is seen in the bursting of iron pipes, the cracking of the rocks into blocks, or shattering them into fragments, thus increas- ing their exposed surfaces many-fold, and ex- posing them to the action of other forces. Exercise i. — Let the student calculate the area of the exposed surface of a cubic foot of rock (a) befor^ and (d) after it has been broken up into cubic inches** (c) Compare a and l>. : Another effect of the freezing of rock is to cause the fragments to " rise slightly at right angles to the inclined surface, and each thawing produces the reverse movement " * under the influence of gravity. Consequently, they slowly "creep" down the declivity (Fig. 5). '4 (7) Ice. — The ice of a stream expands with great force, pushing against the bank. It holds in its mighty grasp all loose stones, boulders, and trees along the banks, and when it breaks up transports them to great distances. If the student has an opportunity, let him watch the breaking up the ice in a river, or even in a smaller stream, and see with what wonder- ful force the great blocks of ice with their bur- dens are crushing each other to pieces in the fury of a spring torrent. Iron bridges are often swept away by the enormous pressure. * Scott's Geology, p. 82. 20 AGRICULTURE. (8) Snowslides. — On the mountain sides great masses of snow which have accumulated throusfh the winter become loosened bv water, as in the case of the landslide, and are drawn down the slope with great momentum, carrying FIG. 5. — SHALES "creeping" UNDER THE ACTION OF FROST. (U. S. G. S.) boulders, vegetation, everything within their path, and literally scraping the solid rock bare. (9) Glaciers. — It is now well established that in both North America and Europe glaciers, or great sheets of moving ice, existed in com- FIG. 6. FORMATION OF GLACIERS. (u. S. G. S.) 21 22 AGRICULTURE. paratively recent geological times; indeed, they are found to-day, though in mtcch /ess size and iiiivibe7' tJian formerly. The causes of the climatic changes which led to the formation and again to the disappearance of the glaciers are unknown. At the time of the great expansion these ice sheets covered nearly all of North America down to 40^ north latitude. Wherever, in high latititudes or altitudes, more snow falls in winter than melts in summer, glaciers are formed (Fig. 6). These glaciers carry with them (i) upon their surfaces, (2) frozen in their interior, and (3) pushed along in front or beneath them, great quantities of rock of all decrees of coarseness, from the gigantic boulders weighing tons to the finest clay. Rocks over which they pass are striated and polished (Fig. 7), and both these and the materials carried may be ground into clay by the enormous pressure of the slowly moving mass. The drift, or this deposit, is distributed over vast tracts, and is stratified or unstratified. The stratified drift is deposited by the water of glacial streams, while the unstratified is simply dropped by the melting ice. At the present time there are great tracts of glacial ice : {a) the Alpine, occupying narrow mountain valleys, as those of the Alps ; (<5) the Piedmont glacier, like the Malaspina, of Alaska PIG. 7.— ACTION OK GLACIER DRIFTS. (U. S. G. S.) 24 AGRICULTURE. — lakes of ice formed by the union of many val- ley glaciers — which occupies an area of thirty by seventy miles, and which is covered along its southern border with morainic soil and great forests ; and (c) continental glaciers, covering vast tracts, comprising hundreds of thousands of miles, like those in Greenland and the antarctic land. (lo) Icebergs. — When glaciers enter the sea fragments are broken off by the tide — some of them hundreds of feet in depth and more than a mile in diameter — and float thousands of miles before they melt and deposit immense quantities of rock. It is evident, then, that the disintegration and transportation of the loose material of the earth's surface by the various forms of water 7'a7y greatly under varying conditions. The chemical action is more rapid in warm, moist countries where vegetation is abundant, while the great variations of heat and cold in the temperate regions, and the powerful frosts in the arctic, render mechanical action more po- tent and swift. Again, this work differs in its usefulness to the agriculturist. Sometimes a mantle of loose, workable material is deposited where a short time before the solid rock reached the surface, or great quantities of organic matter may be deposited which decay and enrich hitherto un NATURE AND FORMATION OF SOILS. 25 productive soil. On the other hand, the hills, if unprotected by forest (Fig. 8), may be liter- ally washed away by rain and gully, rivulet and stream, until fertile farms are transformed into sandy wastes. Field Exercise No. i.* Part i. Work of Aiiftosphere. — {a) Note any rocks worn away by the friction of rain or sand through the action of wind. Note any rocks kept exposed to other atmospheric agencies through the action of wind ; note an}' wind-blown soil; any wind-blown water; vapor. {b) Note any evidences of chemical action; oxidation, hydration, action of carbon dioxide; " rotten rock." Draw a diagram showing successive stages of disinte- gration from solid rock to soil. (This diagram is to represent such a section actually observed in the day's excursion.) [c) Note effects of changes of temperature — that is, alternations of heat and cold — upon rocks. Part 2. Work of Water. — {a) Note evidences of its solvent power. Fill a small bottle with clear water from a spring or brook, and when you return to the labora- tory evaporate a few drops of it to dryness on a piece of glass or in a test-tube, and see if there is any residue; explain. {b) Disintegrating Power of Water. — Note evidences * This outline is meant to be only suggestive of what may be actually seen in a field trip along almost any stream in the north Mississippi valley. Many of the points mentioned will ap- ply toany locality of the United States; some will not. Neither will this outline include anic Life. Everywhere myriads of living forms abound — in the air, in the water, on the land, and in the soil. However, there must have been a time when life did not exist upon the earth. It must have begun in a very humble manner, be- cause the early conditions were such that com- plex organisms could not exist. It is believed by both geologists and embry- ologists that from these simple beings have evolved in succession, through vast ages of time, all the higher and more complicated forms. With the advent of life arose a new and mighty potency in the work of soil formation, and this force becomes the greater as life be- comes more varied and complex. I, Plant Life. — The fact that plants have 28 AGRICULTURE. been from very early geological times, and still are, a powerful, though silent, factor in the pro- cesses of rock disintegration and soil formation is too often overlooked or underestimated. (i) Mechanical or Physical Effects. — Generally, wherever rock has been acted upon by the processes of weathering, vegetation creeps in. It may be some very low form, as fungus, moss, or lichen, but it sends its tiny root-like extensions into the crevices of the rock and forces apart its particles. In the higher forms of vegetation, where the roots are strong and woody, this becomes an important feature (Fig. 9). Huge boulders are burst asunder by the root-pressure of some giant tree; through innumerable rocky crevices larger or smaller root systems are finding their way, opening up the solid rock, and rendering it sus- ceptible to other disintegrating forces (Fig. 9). In this same way myriads of grass roots and roots of herbs and forest trees are pulverizing the solid material of the soil. While plants absorb water from the soil, at the same time, where vegetation is at all dense, they shield the earth's surface from the direct rays of the sun so effectively as to retard evapo- ration. This retained moisture exerts a solvent power upon the rock substances. Grasses, or other plants having thick, matted roots, prove a great protection from the mechan- NATURE AND FORMATION OF SOILS. 29 ical removal of the soil (Fig. lo) by heavy rains or wind. Dense forests serve as windbreaks, and soil blown by the wind is lodged and prevented from further transportation by the trees. These FIG. 9. — ROOTS OF FOREST TREES OPENING A ROCKY Sl'BSOIL. forests, with their masses of roots and decayed leaves, also serve as a blanket in protecting from extremes of heat and cold. Masses of seaweed act as barriers to the surf, and the aerial roots of mangrove trees along 30 AGRICULTURE. tropical coasts break the force of the waves, so that they cannot wash away the mud and sand. (2) Chemical Effects. — The roots of living plants, from their acid secretion, effect a chem- ical action upon the insoluble substances with FIG. 10. — VEGETATION PROTECTING THE SOIL. which they come in contact, rendering them sol- uble, and absorbing into themselves large quan- tities of certain compounds as plant food, thus depriving the soil of this material. That this acid secretion actually corrodes or dissolves rock material was proven by Sachs through actual experiment, which any one may also prove for himself. By the decomposition of vegetation humic acids are formed, which have the power NATURE AND FORMATION OF SOILS. 31 of dissolving many minerals not soluble in rain- water. Since plants can derive their food from much simpler elements than can animals, many scien- tists believe that the first forms of life were those of a very low type of vegetation. The only organisms which could exist upon a bare rock must be those which could subsist upon a purely mineral food obtained from the rock itself, and from the water and gases of the at- mosphere. It has been discovered that even the denuded rocks of very high mountains are cov- ered by a layer of organic matter, evidently formed by microscopic vegetation. These micro- organisms have even been discovered at con- siderable distance in the interior of these rocks. They begin the formation of humus, | and make it possible for other low forms of plant life to creep in, which, in turn, help to prepare the soil for the sustenance of chlorophyll-bearing, or green, plants. Bacteria. — The micro-organisms which are of most importance to agriculture are the bac- teria which (i) oxidize nitrogenous substances, thereby forming nitric acid, and (2 ) those which reduce nitric acid to ammonia or to free ni- trogen. In the processes of nitrification, ammonia is one of the first products formed from ferment- ing organic matter by one species of bacteria. 33 AGRICULTURE. The ammonia (NH3) is oxidized to nitrous acid (HNO2) by another species; this in turn is changed into nitric acid ( HNO,) by still another species. In a similar manner the opposite pro- cess of denitrijication goes on. First, the nitric acid is reduced to nitrous acid, this to ammonia, and then to free nitrogen, each step being per- formed, respectively, by a distinct species of bacteria. Both of these processes may take place in the soil, their extent depending largely upon the oxygen supply. In a well-aerated soil nitrifica- tion takes place, while in an undrakied, poorly ventilated soil denitrification occurs. It has been proven by modern science that the nitrifying organism of the soil is able to sub- sist in a purely mineral environment. Now certain bacteria, or soil ferments, are found in great numbers about plant rootlets — in fact, liv- ing in mutual relationship with them. It is, therefore, thought probable that the action of bacteria has an effect upon the mineral particles of the soil which renders them solvent and pre- pares them for absorption by plants as food.'^' (Year-book, 1895.) Although these bacteria can subsist upon * The value of leguminous plants for worn out or poor soils has long been realized, but not until 1888, when Helriegel pub- lished the results of his investigations, was the real source of their fertilizing power known. NATURE AND FORMATION OF SOILS. 33 minerals, they are far more flourishing in the presence of decaying organic matter. Indeed, their action is believed to hasten the decompo- sition of organic material. So it is that the plant, by its own decomposition, is through these agencies made to contribute to the forma- tion of humus, which is an essential part of true soil. (3) Vegetable Accumulations or Deposits. — Not only living plants exert an influence upon the soil, but when they die their remains form, though very slowly to be sure, accumula- tions of vegetable matter. (a) True soil. — Vegetable accumulation is most important as well as most conspicuous as a mantle of true soil, formed from the decayed vegetation in the forests or grass - covered prairies. (^) Wherever vegetation slowly undergoes decomposition under water carbonaceous accu- mulations are formed. The further decompo- sition proceeds the greater the percent, of car- bon ; thus results peat, lignite, bituminous, or anthracite coal, according to the stage of de- composition reached. {c) In fresh-water lakes and ponds, as well as in the sea, the siliceous cases of microscopic plants known as diatoms form considerable ac- cumulations. I. Animal Life. — Animals have a twofold 34 AGRICULTURE. geological effect: (i) that of disintegration, and (2) that of accumulation. (i) Disintegration. — In the sea even the hardest rocks are made to crumble by marine animals boring into them. In like manner many animals burrow and bore through the soil. ^\\& prairie dog oi the western United States digs a deep burrow in the earth, and casts up a mound at its entrance. There are whole vil- lages of these mounds, which in some localities cover many acres. Muskrats, crayfish, moles, woodchucks, and gophers in countless numbers are performing similar operations. Ants, especially in tropical countries, bring up sand grains from their underground tunnels, and form multitudes of ant-hills sometimes afoot or more in hight. Myriads of other insects, or their larvae, pulverize the soil particles or enrich them with their excreta and decayed bodies. But the most important of these animal agencies in stirring up, pulverizing, mixing, and ventilating the soil is that of the common earth- worm. Darwin, in his investigations upon the earthworm, estimated that in many parts of England "more than ten tons of earth annually pass through their bodies and is brought to the surface on each acre of land." In this way the whole superficial bed of soil would pass through their bodies in a few years. The specific action NATURE AND FORMATION OF SOILS. 35 of earthworms has both a mechanical and a chemical effect. The burrows may extend sev- eral feet under ground, and are connected with each other by underground tunnels, so that the soil is thoroughly exposed to the chemical action of gases and acids of the air and water. The muscular gizzard grinds the stony particles swal- lowed by the worm, making them finer and more succeptible to the humic acids, the gener- ation of which is probably hastened during the digestion of the vegetable mould and half- decayed leaves, upon which the worm feeds. (2) Animal Accumulations. — Calcareous Deposits. — " The sea is constantly receiving from the land materials in solution, the most important of which are the carbonate and sul- phate of lime. Many classes of marine animals extract the calcium carbonate (CaCOj) from the sea-water and form it into hard parts, either as external shells and tests or as internal skeletons. There is also good reason to believe that some, at least, of these organisms are able to convert the sulphate into the carbonate." In shallow seas, where the conditions of warmth and food- supply are favorable, animal accumulations are developed on a large scale. The most impor- tant of these accumulations are those of the corals,* echinoderms, and mollusks. * Scott's Geology, pp. 165-170. 36 AGRICULTURE. Many immense limestone beds were accu- mulated from the shells of mollusks and the skeletons, or calcareous plates, of starfishes, sea- urchins, crinoids, and all sorts of lime-secreting animals. The forameniferal oozes formed from the calcareous shells of microscopic, unicellular animals of the deep sea have a vast geograph- ical extent.* Siliceous Deposits. — The Radiolaria are a group of microscopic animals which make sili- ceous secretions instead of calcareous ones. Phosphate Deposits. — These are terrestial for- mations derived principally from guano, which is composed of the excrement, bones, and re- mains of birds (or in caves, bats). They are found in rainless regions, like Peru and its islands. When the guano is deposited over limestone it gradually changes the limestone from a carbonate to a phosphate of lime. 3. Environmental Changes. — Beavers build dams across streams, and sometimes flood many acres of lowland. By felling trees they inter- rupt the drainage, thus forming marshes favor- ing the formation of peat beds. Man also may change natural conditions, either purposely or incidentally, by planting or destroying trees, thus causing the protection (Fig. 11) or denudation of hillside slopes; by * Jordan and Kellogg's Aniiiuil Life, p. 18. a _ 38 AGRICULTURE. plowing and harrowing-, thereby exposing the soil to the action of the wind and rain ; by bor- ing wells, and excavating mines and quarries ; by controlling or directing the water of rivers and streams, and by irrigating dry or desert regions (Fig. 12), thus changing the natural environment very greatly if not altogether (Fig- 13)- 4. Field Exercise No. 2. — A Study of Organic Life as a Factor in Soil Formation. Part i. Mechanical Action. — {a) Note the disinte- grating processes of plant life. Pull off the moss, or lichens, growing upon a solid rock, and see how far be- neath the surface the root-like extensions have crept. Measure and calculate the length of some great root- system which is exposed along the bank of a stream, or find rocks burst asunder by root action ; note examples of retarded evaporation. {b) Note the protection of soil by plants. {/) Note vegetable accumulations. In the woods, notice the formation of humus from the decayed leaves, twigs, and bark, and contrast the soil with that in the meadows, roads, and lawns. Account for these varia- tions, and discuss all factors concerned, as sunlight, air currents, depth of feeding roots, and kinds of material obtained by them at the different strata. What is the relative value of the soil from each place ? Take a sam- ple of each of these soils back to the laboratory, and try to grow a plant of the same kind and size in each soil, and record and compare your results. Part 2. Work of Disintegrating ami Pulverizing the Soil. — (a) Describe the work of as many different kinds of animals as it is possible to find in your trip ; dig up a block of soil containing the burrows of earthworms, FIG. 12. — VIEW OF AN IRRIGATING DITCH WHEN MADE. FIG. 13. — VIEW OF SAME DITCH TEN YEARS LATER. 40 AGRICULTURE. and make a drawing of both vertical and horizontal, or connecting, channels. (/'') Note any environmental changes made by man or other animals, or by plants. {c) Note any fossils, or animal accumulations. (d) Remarks and conclusions. (It is to be understood that any observation made under any of the foregoing heads is to be written up in its place, whether it is men- tioned in this outline or not.) [References after Chaptt r III.] OUTLINE OF CHAPTER II. CLASSIFICATION AND PHYSICAL PROPERTIES OF SOILS ^.— KINDS AS TO DEPOSITION. I. Sedentary, or Residual, Soils. II. Transported Soils. 1. Drift. (i) Boulder Clay, or Till. (2) Stratified Drift. 2. Alluvial Soils. 7?.— KINDS OF SOIL AS TO DERIVATION. I. Sandy, or Siliceous, Soils. II. Clayey, or Argillaceous, Soils. III. Limy, or Calcareous, Soils. IV. Humous Soils. C— PHYSICAL PROPERTIES OF SOILS. Experiments 4, 5, 6, 7. 41 CHAPTER II. CLASSIFICATION AND PHYSICAL PROPERTIES OF SOILS. ^.— KINDS AS TO DEPOSITION. I. Sedentary, or Residual, Soils. These are formed where they lie by the weath- ering of the rocks which underlie them. They consist of those parts of the decayed rock which are not easily dissolved and carried away by rains. These soils vary in depth. In certain local- ities the soil is only about seven feet thick, and poor in soluble compounds, such as lime. " In some parts of our Southern States the felspathic rocks are often found thoroughly disintegrated to the depths of 50 to 100 feet." '="' The natui^e of residual soils depends upon the kind of bed-rock underlying them and' the weathering. " Thus, limestones make the rich Blue-grass Region of Kentucky, and sandstones make the poorer part of the State." f True soil, usually darker in color on account of the vegetable mould which it contains, and of the "oxidation and hydration of its minerals," forms the surface layer. Below it is the subsoil, which is often divided into layers, and which some- * Scott's Geology, p. 77. ■|- Gilbert and Brigham, Physical Geology , p. 87. 43 44 AGRICULTURE. times contains great masses of the parent rock which have not been decomposed. By grada- tions the subsoil shades into rotton rock, and from this into solid rock. II. Transported Soils. The soils upon vast areas of the United States have not been formed from the rock formation which underlies them, but they have been transported thither over long distances by ice, or water, or wind (Chapter I.). 1. Drift. — Soils deposited by ice are called "drift," and may be distinguished by the pres- ence of boulders. These soils usually consist of a variety of minerals brought together from differ- ent rock formations through the action of glaciers. Drift soils cover great areas in the United States north of the 39th parallel. (i) Boulder Clay, or Till, is the unstratified material which covers the greater part of gla- ciated areas. It is composed partly of preglacial Soils and stones pushed before the glaciers, and partly of finely pulverized rock gathered from the bed-rock by the grinding and scraping or the glacier itself. (2) Stratified Drift is also found where it has been deposited by the water of glacial streams. 2. Alluvial Soils are those which have been transported by streams of water (Chapter I.). These are usually stratified, often differing CLASSIFICATION AND PROPERTIES OF SOILS. 45 in the kind of rock material as well as in its state of disintegration. " The soils of the cen- tral valley of California have mainly come down from the Sierras by the wash of the rivers. The soils of Louisiana have been brought from the Rocky Mountains, from the great plains, from the prairies, and from the plateaus and moun- tains of the Appalachian region. They have been transferred by the Mississippi and its branches. The earthy mantle of Connecticut and Rhode Island is in part composed of rock flour and stones brought from Massachusetts and the northern New England States. The Connecticut and other rivers have done some of this work, but much more is due to the great glacier moving south over that region." "' ^.— KINDS OF SOIL AS TO DERIVATION. As has been said, the basis of soils is disin- tegrated rock. Hence, the physical and chem- ical properties of soils depend upon the geolog- ical formation of the mass of rock from which it is derived. If a deposit of quartz (Si02), which it is esti- mated composes one-half of the rocks of the earth, has been slowly disintegrated it will result in hard, distinct grains of sand, since quartz dis- integrates with difficulty. Gilbert and Brigham, P/iysical Geology, p. 87. 46 AGRICULTURE. I. Sand. Sand is "light and open" — that is, easy to work. It absorbs very little moisture from the air. It has little power of chemically holding plant-food. Sandy soils are usually poor in phosphoric acid and potash, two important plant- foods. II. Clay. If a feldspar — which consists of silica, alu- mina, and one or more of the alkalies, potash, soda, or lime — has been disintegrated, clay will result. The term "clay," however, is very loosely applied to almost any kind of finely pul- verized rock, or mud. Clay soils are hard to work; they absorb mois- ture from the air readily. They contain, chem- ically, much plant-food, being often rich in potash and poor in lime and phosphoric acid. Shale is a rock consisting of very thin layers. Its composition varies greatly, sometimes grad- ing into limestone or finely grained sandstone. Shales form mud or clay. III. Calcareous Soils. Some soils are largely composed of carbon- ate of lime from the disintegration of limestone, which is a soft rock and one easily dissolved. Soils containing a large per cent, of limestone are called calcareous soils. Lime makes clay soils more easily worked and sandy soils more 48 AGRICULTURE. compact. It hastens the decay o^ vegetable matter. Limy soils are poor in potash and often rich in phosphates (see " Lime," p. 95). !V. Humous Soils- The decaying organic matter in soils is com- posed of compounds of nitrogen, hydrogen, oxygen, and carbon, and is called " humus." Soils containing a large per cent, of this or- ganic matter are designated as " humous soils." Humus gives a dark brown or black- ish color to the soil. Leaf mould very largely consists of humus. Either a sandy or a clay soil is improved by humus, not only on ac- count of the additional plant-food, such as car- bon dioxide, ammonia, and water, which is fur- nished by its ultimate decomposition, but more especially on account of the improvement of the physical condition of the soil. Humus absorbs and retains moisture, and thus improves a sandy soil. It improves a clay soil by making it less compact and better aerated. It improves the physical condition of worn-out soils. Humous soils are often rich in nitrogen and poor in mineral plant-food. A soil formed from the addition of humus to a sand, clay, or calcarc ous loam is called a clay or argillaceous loam. or calcareous loam, according to the kind of soil which forms the basis. CLASSIFICATION AND PROPERTIES OF SOIL 49 C— PHYSICAL PROPERTIES. Experiment 4. Part i. — (a) Collect a quantity of dry sand, and one of dry clay, and one of dry garden loam, and one of dry humus. Keep these in a dry place in separate boxes, for use in the following experiments. ((^) Get four small, similar-sized boxes, and fill each box with one of these soils. {c) Weigh each one separately. Which is heaviest? Which lightest ? {d) How many cubic inches of soil in each box ? What part of a cubic foot ? How many square feet in an acre ? How much would an acre of soil to the depth of one foot weigh if each cubic foot weighed the same as a cubic foot of your sample of garden soil ? (if) If this acre produced a crop of twenty-five bushels of wheat and 2,500 pounds of straw, how many pounds* has this crop taken from one acre of soil ? This may seem a very small amount to be taken from the soil, but it must be borne in mind that some soils contain a very small per cent., or fraction of a per cent., of some of the very essential plant-foods (as, potash, phosphoric acid, or nitrates), while plants vary in their demands for these different foods. So it is that certain essential plant- foods, as nitrogen, may be nearly exhausted from a given soil by repeatedly growing certain plants which make large demands of that particular element from the soil, and yet the same soil may be abundantly able to sustain other plants which demand less of that element from the soil, f Part 2. — {a) Place these four boxes (Part i, ^) of soils in a cool, dry place. With them place three similar * At least 95 per cent, of the material composing the plant is obtained from the air and water, and but 5 per cent, from the soil. f See " Leguminous Plants" and " Fertilizers." 50 AGRICULTURE boxes, each containing one of tliese soils, sand, clay, loam and humus, which has been thoroughly saturated with water. {/>) Put a thermometer with the bulb at the depth of two inches in each of these eight boxes, and allow them to stand until the fol- lowing morning ; then record the temperature of each. {c) Place all the boxes where they will be equally ex- posed to bright sunlight, and note the temperature of each soil every two hours from 8 a.m. to 4 P.M., taking care to note wheth- er the sun is under a cloud at the time of each observa- tion. (a) Upon a piece of co-ordinate paper indicate the temperature curve of each of these soils dry, and that of each of these soils wet, similar to that indicated for a humous soil in Fig. 15- In these curves (Fig. 15) the space between each two horizontal lines represents one degree, while that between each two vertical lines represents two hours. / \ / \ / \ / / \\ '/ \ \ / \ 1 \ / /* / / y fA.7n. fOAJH. FIG. 15 /z;k S.M ¥fM. Uf/H. TEMPERATURE CURVES OF A HUMOUS SOIL. CLASSIFICATION AND PROPERTIES OF SOILS 51 Let the temperature curve of the loam be indicated by an unbroken line '-, that of sand by a l^roken line , and that of clay by a dotted line , and that of humus by a line and then a dot -.-.-.- Compare. Give a reason for the differences in tem- perature between these soils. ((?) On the next bright day again saturate one box of each of these soils, and place the dry and wet soils in the bright sunlight. At noon record the temperatuVe of each, and remove all to the shade indoors. {/) Note the temperature at 2 iM\i. and 4 p.m. Which soil, dry, retains the greatest amount of heat ? Which soil, wet, retains the greatest amount of heat? (g) What conclusion of practical value do you draw from your results? Could you improve the condition of any or all of these soils with regard to the absorption and retention of heat? How? Part 3 — (a) Thoi'oughly moisten these soils and try to mold a handful of each kind (sand, clay, loam, humus) into some desired form. (d) Which soil has the greatest power of holding its particles together? Which the least? Which soil will be most liable to puddle ? Which most apt to bake ? (<•) Mix each of these soils with one-fifth its bulk of lime, and repeat {a). (,/) Mix each with one-third sand, and repeat (a). (sL ed perc o 1 a tion. {Ji) Compare the color and the odor of the water per- colated. Through which of these soils will soluble plant-food most readily leach ? Which soil will absorb the most plant-food from the water which percolates through it ? CLASSIFICATION AND PROPERTIES OF SOIL. 53 (/*) Allow the liquid to drip for half an hour, and com- pare the water which now percolates through with that fit St percolated. Is it safe to depend upon the soil to act as a filter in purifying the water of wells from organic matter ? (y) Very carefully pour off all the water remaining in the tubes, and weigh each tube with its contents, record the weights, and compare with those of (e). Which soil retained the greatest amount of water ? Experiment 6. — (a) Procure a set of capillary tubes (Fig, 17) — four or five tubes — varying in diameter from a hair tube to one one-fourth inch in diameter. (^) Half fill a beaker, or tumbler, with water colored witli red ink. (c) In a piece of pasteboard punch several holes corresponding in size and numl)er to the tubes used; thrust the tubes through the holes to three-fourths the distance, below, of the height of the beaker. Now cover the beaker with this pasteboard, allowing the tubes to extend down into the colored liquid (Fig. 17). (d) Note the height to which the Capillary rise of liquid not liquid riscs in each tube. In which shown. highest ? The wall of the tube attracts the film of water next to it, and tends to spread It out over the surface of the tube, overcoming the resistance of the surface tension of the liquid itself. Notice that the surface of the liquid both inside and outside of the tubes assumes a concave shape, on account of the creeping up of the liquid next to the wall, caused by the attraction between FIG, 17, — APPARATUS FOR EXPERIMENT 6. AGRICULTURE. 1 ■ 1 i 1' H 1 Hi Ill * i 1 ■' i i, 1 f ■■^PlpB ilnll ' lllllil'li^ ■^H^^^^^^^Hk ' r FIG. l8. — APPARATUS FOR EXPERIMENT "J, the solid and liquid substances. (See any good physics for capillary action). The pores in an open, or gravelly, soil act as the larger tubes, while the smaller pores of a CLASSIFICATION AND PROPERTIES OF SOILS. 55 less open or more finely pulverized soil act as the fine tubes in conveying moisture. Experiment 7. — (a) Take four glass tubes one-half inch or more in diameter and four feet in length * (Fig. 18). Over the bottom of each of these tubes firmly tie a square of cheese-cloth. (/') Thoroughly pulverize the dried clay and loam. Firmly and evenly fill each tube with the sand, clay, loam, and humus respectively. Stand them in a pan of water with a layer of gravel in the bottom, and record the time of so doing. Keep the pan well filled with water. (f) At intervals — from one to three hours during the first day or two — note the height of the water in each tube. After the second day, once a day will be often enough to make observations. ((/) Continue the observations and records until the water no longer rises in any tube. ((f) In which tube did the water rise most rapidly? In which to the greatest height? This poiver cf dra7ving water upward through the soil is called capillarit). Exercise 2. — From the data obtained in performing these experiments, write up the. phsicaly properties of each of these four kinds of soil. Your description of each soil should cover the following points: Color, weight of a cubic foot, light or heavy to work, power to absorb heat, power to retain heat, power of holding soil particles togetlier, porosity, power to absorb and retain water, capillarity, and any remarks. [References after Chapter III.] *Straight lamp-chimneys may be substituted for the long glass tubing. It is more economical, and will give satisfactory results, OUTLINE OF CHAPTER III. SOIL MOISTURE AND PREPARATION OF THE SOIL. ^.— SOIL MOISTURE. I. Kinds of Moisture. 1. Ground Water. 2. Capillary Water. 3. Hygroscopic Water. Experiment 8. II. Relation to Plants. 1. Dissolves Plant-food. 2. Conveys Plant-food. Experiment 9. 3. Constitutes Plant- food. Experiment 10. 4. Tends to Regulate Temperature. III. Field Exercise No. 3. ^.—PREPARATION OF THE SOIU I. Drainage. Experiments ii and 12. II. Irrigation. Experiment 13. III. Preparation of Seed-bed. 1. Plowing. 2. Surface Tillage. Experiment 14. C— REFERENCES. 57 CHAPTER III. SOIL MOISTURE AND PREPARATION OF THE SOIL. y^.— SOIL MOISTURE. It is evident from the foregoing experiments that the particles of soil and, therefore, of the spaces between them, vary in size. When the soil is dry most of the spaces are filled with air, but when the soil becomes wet the air is driven out by the water. I. Kinds of Moisture. 1. Ground ]\\itcr. — The water which perco- lates through the soil under the influence of gravity until it reaches an impervious layer of hard-pan, or rock, is called the free or ground water of the soil. Above the hard-pan, or rock, is a layer — varying in thickness — of saturated, or water-soaked, soil. It is from this free water that the supply is obtained for springs and wells. In dry weather it is drawn upon by capillary action to furnish the moisture for vegetation, but if this free water is allowed to stand too near the surface of the soil it is injurious to most plants. In soils of close texture it be- comes necessary to remove the surplus water by drainage. 2. Capillary Water is that which is held in the spaces between the soil particles by capillary 59 (JO AGRICULTURE. attraction, or the overcoming of the influence of gravity by the adhesion between the water and the solid particles, and is of direct use to plants. 3. Hygroscopic Moisture. — Each particle of soil is surrounded by a film of moisture, or hy- groscopic water. It is held so firmly that even roadside dust contains this film. Experiment 8. — Fill a test-tube one-third full of dry roadside dust; heat it gradually to a high temper- ature. Allow it to cool, and see if any moisture con- denses upon the tube. II. Relation to Plants. 1. Dissolves Plant-food. — This surface film of water, through the carbonic and humic acids which it contains (Chapter I.), acts directly upon the plant-foods locked up in the soil, dis- solving the mineral substances and giving them up to the surrounding capillary water. 2. Conveys Plant-food. — As has been seen, solids have an attraction for liquids. It is also true that denser or thicker liquids have an at- traction for thinner ones; so it is, as the mois- ture is evaporated from the leaves and green bark of plants, leaving behind the solid sub- stances, the fluid in the plant becomes denser than the soil water, and there is thus established, through the cell wall of the plant, a flow of the thinner liquid, or soil water, toward the denser protoplasm of the cells. This process is called SOIL MOISTURE AND PREPARATION OF SOIL. 61 osmosis. Thus the soil water not only dissolves the plant-food, but through capillary action and osmosis actually carries this food to the plant. Experiment 9. — {a) Take any single-stemmed grow- ing plant, place the roots in a wide-mouthed bottle half full of water. {b) Make the bottle air-tight (to avoid the evaporation of the water) by splitting a cork into halves, hollowing out the center, and fitting them about the stem of the plant ; now fill any crevice about the stem, or in the top of the cork, with melted paraffin.* Invert the bottle to see if any water escapes ; if so, the cork is not fitted air-tight, and melted paraffin must be applied where it leaks. (c) When the bottle is air- tight weigh it, and record date and weight. The follow- ing day place it where the plant will be exposed to direct sunlight, and weigh every day or two for two or three weeks. How much water has the plant used ? Of what use to the plant was the water? Hellriegel, through his experiments, found FIG. 19. — APPARATUS FOR EXPERIMENT 9. * Paraffin melts at a low temperature, and will not injure the plant if carefully applied. 62 AGRICULTURE. that the amounts of water evaporated from the soil and given to the air ahiiost wholly through the plant were : by barley and red clover, 3 lo pounds of water to one pound of dry matter produced; oats, 376 pounds; peas, 273 pounds ; and buckwheat, 363 pounds to one pound of dry matter. Plants differ in their de- mands for water, hence some kinds of plants are found upon dry soils and others upon wet soils. 3. Constitutes Plant-food. — Water itself con- stitutes an important plant food. Experiment 10. — (^ factors of plant growtJi — water, air, and heat — in the soil. It is evident that dif- ferent soils require different methods, and that the same soil requires different treatment for different plants. Tillage does not add plant- food to the soil, but it does render food already in the soil available to the plant. ^.—PREPARATION OF THE SOIL. The first thing for a farmer to do, and then to continue doing, is to study his soils, taking into 64 AGRICULTURE. consideration the climate. The next thine to do is to consider what crops are best adapted to the different soils, remembering that both the immediate crops and the condition of the soil for future crops are to be regarded. Thus fol- lows the consideration of the treatment of each kind of soil for the crop selected or tJie prepara- tio7i and tillage of the soil. I. Drainage. Experiment ii. — {a) Take two eight-inch flower-pots and label them i and 2, respectively. In No. i pour a sufficient amount of melted paraffin in the bottom to plug up the hole, so that no air may pass in, and no water pass out through the bottom of the pot. In the bottom of No. 2 place a layer about an inch in depth of stones or pieces of broken pottery. {h) Nearly fill each pot with a mixture of three-fourths good soil, thoroughly pulverized, and one-fourth sand. (c) Place in each pot a young, healthy plant of the same size and kind. (^) Now carefully sprinkle each with water until the soil is saturated. {e) After a day or two put these pots in a sunny win- dow. (/) In each place a thermometer, with the bulb at a depth of two inches i^g) Every two or three days note the temperature, and the condition of the soil and of the plants in each pot. In which pot does the water percolate through the soil the more rapidly? If each of these conditions of soil moisture was found in separate fields, which field would be more apt to be flooded in time of heavy rains? In which could air penetrate the more readily? In which would the temperature be higher? SOIL MOISTURE AND PREPARATION OF SOIL. 65 {h) At regular intervals — say, every two or three days — apply equal quantities of water to each of these pots. (/ ) In about five or six weeks remove the soil — plant and all (see "Propagation of Plants") — and note the depths to which the roots have penetrated. In which have they gone the deeper, the drained or undrained soil ? If these conditions of soil moisture existed in the open field in early spring, and were followed by a drought, how would these root systems compare in aiding tlie plant to withstand it? In nature, when these root systems die, how would they compare in affecting the porosity of the soil ? How would such soils affect the nitrogen- fixing bacteria (Chapter I.)? How would the work of earth-worms, grubs, and other burrowing animals com- pare in these two soils ? Soils having a loose and open subsoil are nat- urally underdrained, and do not need to be arti- ficially drained. Soils of fine texture, or those having a clay or hard subsoil, do not allow the free water to percolate through them, and it stands very near the surface, unless artificially drained. It is not as the water passes down through the soil that it is carried away by drains, but as it rises again in saturating the soil above the impervious layer of hard-pan or bed-rock. The deeper the drain the greater the area drain- ed, hence the wider apart the drains may be. ExPERiMNT 12. — {a) Procure a keg, or barrel, which does not leak, and in its side bore two or three holes, one above the other, about twelve inches apart, the first hole being six inches from the bottom. {b) Nearly fill this keg, or barrel, with soil. Shake it down firmly. 66 AGRICULTURE. (<■) Gradually pour water into the center of the keg — where the soil should be, perhaps, a little lower — until it runs out of some one of the holes. According to your result, which would carry off the water first — a shallow or a deep drain ? In shallow drains there is clanger that the tile may be injured by frost. The depth to which a drain should be laid depends upon the char- acter of the soil; the more compact soil requires more numerous and shallower drains. Three or four feet deep and one hundred feet apart are sufficient for ordinary farm crops. " The carry- ing" capacity of tile varies with the square of the diameter." '"' In every drain the tile should in- crease in size as the quantity of water increases. Tile varying from three to six inches, with larger size for mains, are generally used. Since tile-drains admit more or less atmos- pheric air, as the temperature and pressure of the atmosphere rise and fall, the circula- tion of the air is produced below the roots of plants as well as above them. II. Irrigation. Experiment 13. — (a) Procure a box about three feet long, one and one-half wide, and one foot deep. (d) In the center of one side, near the bottom, bore a hole, and fit into it a cork (Fig. 20). (c) Nearly fill the box with dry, pulverized soil, and shake it down well. (d) Now make a shallow trencli in the soil, across tlie Soils unci Crops, Morrow and Hunt, p. 66. SOIL MOISTURE AND PREPARATION OF SOIL. G7 center of the box, and slovvl}' pour water into it, until the soil at the bottom of the box is moist, as determined by removing the cork, and thrusting a rod, or straw, into the hole. (.— REFERENCES. CHAPTER IV. THE SOIL AS RELATED TO PLANTS. ^.— USES OF THE SOIL TO PLANTS. I. The Soil Serves as a Foothold. The roots penetrate the soil and brace the plants against the wind, and hold them erect so that they more readily obtain air and light. The necessity for this support is made greater by the elongation of the stem in the struggle for liorht. II. It Affords Important Food Clements. Although but 5 per cent, of the food supply of plants is obtained from the soil, it does not fol- low that this 5 per cent, may be omitted. On the contrary, many of the soil-furnished ele- ments are absolutely necessary to the life and development of plants. III. The Soil Acts as a Storehouse for Water, so that the plant may draw upon its supply con- tinuously, or much more nearly so than if it de- pended only upon the moisture obtained from the air and from that obtained for immediate use from rains. This soil water is invaluable both as a food and as a solvent for other con- stituents of plant-food, since plants can only take up substances which are soluble in the soil 77 78 AGRICULTURE. water (which usually contains organic acids), or which may be rendered soluble by the acid reac- tion of the roots. IV. It Tends to Retain and Regulate the Heat of the sun, and transform it into energy which plants can use. V. It Serves as a Habitation for Soil Bacteria, which transforms the unavailable free nitrogen of the air into nitrates available for the use of plants. ^..—CONSTITUENTS OF PLANTS. I. Chemical Analysis of Plants. Many analyses of the tissues of different plants have been made (though by no means of all plants), and through these analyses it has been ascertained that one plant may contain certain compounds — or particular combinations of these elements — which do not e\;ist in some other plants. These analyses show that all plants are essentially made up of fourteen ele- ments, or about that number. II. Sources o? Plant-food. Four of these elements — carbon, oxygen, hy- drogen, and nitrogen — are obtained directly or indirectly from the air, while the soil must sup- ply the remaining ten elements : iron, calcium, silicon, chlorine, sulphur, phosphorus, potas- sium, sodium, magnesium, and manganese. The food elements obtained from the soil are the THE SOIL AS RELATED TO PLANTS. 79 more numerous, but they form a very small per cent, of the quantity of plant tissues (not over four or five per cent, altogether), while the ele- ments obtained indirectly or directly from the air form 95 per cent, or more of the quantity. I . Air-derived Elements. ( I ) Carbon. — Nearly half of the solid mate- rial of plants is carbon. It is found in the oils, starch, sugar, and albuminoids.;]; The leaves take in carbon dioxide from the air and decompose it (in the light) into its elements, carbon and oxygen, building up other compounds with the carbon and giving off the greater part of the oxygen. (2) Oxygen too may be directly taken from the air by leaves, buds, and flowers, or by the roots. It is also taken in in large quantities in the water absorbed. Oxygen forms a part of nearly all the compounds found in plants. (3) Hydrogen, in combination with oxygen forming water, is an important element in plants There is no other compound so abun- dant in plants as that of water, and none whose function is more important, since it holds in so- lution other elements, or compounds, of plant- foods, and acts as a medium for transporting them to every tissue and cell of the plant. (4) Nitrogen is an essential element in all the green and woody parts of plants — in fact, of all the protoplasm, or living substance, of the plant. 80 AGRICULTURE. Insufficient available nitrogen. Sufficient available nitrogen. FIG. 27. — SHOWING EFFECT OF NITRATE. It promotes vegetative growth rather than fruit- fulness. The presence of sufficient nitrogen available* to the plant — unless counteracted by some phosphate — is manifested by the vigor and deep green color of the leaf, with possibly retarded flowers and fruit, while the lack of available nitrogen is shown by scanty and pale foliage. The quantity available greatly affects * Available plant-food is in such form that the plants can and will use it. THE SOIL AS RELATED TO PLANTS. 81 the amount of nitrogen stored up in the plant, and thus the access or lack of available nitrogen largely modifies the nutritive value of the plant as food for animals. Four-fifths of the atmosphere is composed of this element so important to plant life, but most plants can be supplied root and branch with an abundance of nitrogen gas and yet starve for the want of nitrogen ; for no green plants can take in free nitroQfen. It must be combined with other elements in such a manner as to form compounds soluble in the soil water, so that it may be taken up by the roots.* The nitrates and ammonium salts are such com- pounds. There are certain kinds of plants which are intimately connected with particular forms of bacteria. This relation f is mutually beneficial. The bacteria work upon the roots of the plants, forming nodules (Fig. 28), and in turn convert the free nitrogen of the air in the soil into soluble nitrates for the use of the plant hosts. II Since most plants do not have access to the exhaustless supply of nitrogen afforded by the air, and there is only a small per cent, of avail- able nitrogen in ordinary soil, and since nitrogen * ' ' Some plants absorb through their /laves a very small per cent, of ammonia directly from the air." — Yeai-hook, United States Department of Agriculture, 1901. f Symbiosis. II See " Leguminous Plants." 82 AGRICULTURE. is SO essential to plant growth, it must be sup- plied in some other way. This phase of the subject will be further discussed under " Fertil- izers." All of the food elements obtained from the air, except nitrogen, are directly available from that source, so need no further mention. 2. Soil-derived Elements. Of the ten elements obtained from the soil, all except phosphorus, potassium, and lime are present in sufficient quantities, and in such form as to supply the needs of plants, except in special cases. (i) Phosphorus. — It has been proven by re- peated experiments that phosphorus in the form of phosphates ■'^' is essential to the healthy de- velopment of plants. Growth cannot take place without the presence of phosphorus in the nucleus of the cells. It helps in the assimila- tion of other food, induces seed-formation and the maturity of the plant, and assists in trans- ferrinor the albuminoids to the seed. The presence of phosphorus in an available form, if uncounteracted, is manifested by early maturity and plump, well-filled seeds. Ordinary soils are in time impoverished of the natural supply of available phosphates unless a portion * " It has been well established that the salts of phosphoric acid — ox phosphates — are the only source from which phosphorus of plants can be derived." — Bulletin 94, Maryland Agricultural Experiment Station. FIU. 2S. — lUBERCLES ON VELVET BEAN PKUDUCED BY INOCULATION. 83 84 AGRICULTURE. of that taken up by repeated crops, particularly of grain, is in some way returned to the soil. This plant-food (phosphate) also will be further discussed under " Fertilizers." (2) Potassium. — Pure potassium is a silvery white metal, but it does not exist in nature un- combined with other elements. Potassium com- pounds are important ingredients in the forma- tion of starch in the leaves and the transference of starch to the fruit. Since starch is so impor- tant in the formation of wood, it follows that the salts of potassium are essential to the devel- opment of the firm, woody tissue of the stems. Potassium forms the base of the acids of fruits and over half the ash of fruits. It is particularly necessary to fruit and root crops. It is also found in the juices of plants which are somewhat acid, where it neutralizes a part of such acids — as, citric, tartaric, and oxalic — by forming the salts of these acids. Potassium forms a large per cent, of the wood of fruit-trees. C— FERTILITY OF THE SOIL. A fertile soil "contains all the material req- uisite for the nutrition of plants in the required quantity and in the proper form." That is, all the materials for the nutrition of plants not de- rived from the air are contained in a fertile soil. One must know whether the food elements THE SOIL AS RELATED TO PLANTS. 85 of the desired crop are present in the soil. This question can be answered by chemical analyses of plants and of soils. I. Chemical Analysis of Soils. If the required elements for a certain crop are not present in the soil they must be sup- plied by a fertilizer, or some other crop sown. But if chemical analysis does show the neces- sary elements to be present, it does not satis- factorily answer the question as to whether that food is available for the use of the plant ; that is, whether conditions are such that the plant can and will use this food. As has already been shown, the chemical composition of the rock from which the soil is obtained, the texture, drainage, temperature, tillage, ventilation, and water content of the soil — which determine the delicate and little- understood life processes of the plant— all are factors in the productiveness of the soil. There are so many conditions, then, that enter into the productiveness of the soil which chem- ical analysis cannot take into account that it is generally of little practical use to the farmer. II. Vegetation Experiments. These are of much value in determining just what fertilizer is needed, but they require time. If, however, the farmer will do as the United States Department of Agriculture advises. 86 AGRICULTURE. "make his farm an experiment station," he can solve these problems from year to year without much loss of time and land, and with great profit. The food elements most apt to be lacking in ordinary soils are nitrogen, phosphorus, and potassium. The appearance of the plants (see page 80) often indicates their specific needs. But one may find out more definitely by apply- ing one kind of fertilizer — as, sulphate of potash — to one plot of a field, and another kind of fer- tilizer — as, sodium nitrate or superphosphate of lime — to another plot, and a complete fertilizer, or mixture of the three (see page 94), upon a third plot, and comparing results carefully with those of a plot to which no fertilizer has been added. The next year the whole field may be treated with the particular fertilizer which the results of these experiments show is needed. If other conditions are right a heavy yield maybe ex- pected. These experiments may show the need of one or of all three of the fertilizers^nitrate, phos- phate, or potash ; or it may be that none of them increase the yield, when one must look to other conditions of soil, or plant, to solve the difficulty. III. Fertilization of the Soil. I . Commercial Fertilizers. (i) Nitrogenous Compounds. — The nitro- genous compounds used as commercial fertilizers THE SOIL AS RELATED TO PLANTS. 87 are obtained from animal, mineral, and vegetable sources, but the source of fertilizers has nothing whatever to do with their value as such. The value depends upon the form in which a fer- tilizer contains the particular plant-food desired. The nitropfen, if wanted for the immediate use of the plant, is best in the form of a nitrate, since it is soluble, and may be better distributed through the soil to the feeding roots, and is readily taken up by them. Ammonia is the next nitrogeneous plant-food in order as regards availability. Some plants can use ammonium salts, which are soluble in water, and thus are easily distributed through- out the soil to the roots. As a rule, however, the salts of ammonia are changed into nitrates (see " Nitrifying Bacteria "), which is done very rapidly in the soil before being used by plants. Animal or vegetable products cannot furnish available nitrogen to plants until decomposition takes place; hence the more rapid the decay of an organic fertilizer the more readily available is its nitrogen, since it must first be converted into ammonia and then into nitrates. (See "Nitrifying Bacteria.") Amone the fertilizers of animal orisfin, which are largely used on account of their rapid decay and comparative inexpensiveness, are : dried blood, dried meat and fish, hoof-meal, and guano. Others — as, wool, hair, and leather — decay more 88 AGRICULTURE. slowly, and hence the nitrogen Is very slowly available. One of the best vegetable nitrogenous fertil- izers is cottonseed-meal. It is largely used in the South, but its usefulness as a food for cattle makes it too expensive, in many cases, for a fer- tilizer. Castor pomace, obtained as a waste product in extracting the oil from the castor bean, is of no value as a food, and decays rapidly in the soil, hence makes a useful and in- expensive fertilizer, though it contains only about one-half as great a per cent, of nitrogen as chemically pure sodium nitrate. Mineral Sources. — Soluble nitrate is com- monly obtained as nitrate of soda, or "Chile saltpeter," which is found in deposits in the rain- less regions of the Peruvian coast. It contains a large per cent, of common salt, but when purified, as prepared for commerce, it Is 95 per cent., or more, pure sodium nitrate (NaNO,), and about 15 or 16 per cent, of this is nitrogen. Sulphate of ammonia, (NH4)2S04, is formed from coal as waste material in the manufacture of gas and coke, also from the dry distillation of animal bone in the making of bone-black. It generally contains about 20 per cent, of nitrogen, making It the richest in nitrogen of any of the commercial fertilizers. It is quick to act, and is readily distributed in the soil, and, THE SOIL AS RELATED TO PLANTS. 89 considering its concentrated form, is compara- tively inexpensive. (2) Phosphorous Compounds. — The com- pounds of phosphorus with Hme, magnesia, iron, and alumina are widely distributed in the soils, but they are insoluble in water, and hence are so slowly available as to be insufficient to fur- nish the necessary supply for repeated crops. Phosphate of lime is the compound used most in the manufacture of commercial fertilizers. The mineral or rock calcium phosphate, or ani- mal phosphates — as, bone-black and bone-ash, or animal bone — is treated with sulphuric acid (H2SOJ, in order to render the insoluble tri- calcium phosphate, Ca3(PO^),„ soluble. The sol- uble phosphate made from the bone-black or bone ash is best, because more of the phosphate may be converted into a soluble form. It makes a fine, dry, easily handled fertilizer. The insol- uble, or tri-calcium phosphate, is treated with sulphuric acid, and a large per cent, of it is rendered soluble by two parts of the lime uniting with the sulphuric acid to form gypsum (2CaS04). This mixture of gypsum * and the soluble phosphate (mono-calcium phosphate) is sold as a fertilizer under the name of super- phosphate of lime. It is probable also that some of the tri-calcium phosphate loses only one part of the lime and becomes di-calcium * Remsen's Inorganic Chemistry, p. 328. 90 AGRICULTURE. phosphate, which is not soluble in pure water, but is soluble in the acid soil waters and the acids exuded by the rootlets, and is, therefore, available to plants. So that the mono-calcium and di-calcium phosphates contained in a com- mercial fertilizer together are called the "avail- able phosphoric acid" (see Table). Mono-cal- cium phosphate is immediately available to plants, and will give quick returns ; but that which remains in the soil changes to the di-cal- cium, or reverted form, which is precipitated as a fine powder, and is easily dissolved through the acid reaction of the roots. The supply for manufacturing these fertilizers comes largely from South Carolina, which has, perhaps, the richest deposits of rock phosphates in the world. Other valuable deposits are found in Florida, consisting not only of phosphates of lime, but also of phosphates of iron and alumina. Still others are found in Tennessee, Pennsyl- vania, and Virginia. Bone-black is obtained by heating animal bones in the absence of air, when the gases and oily matters are driven off, and charred bone or bone charcoal is left. This is used for refining sugar ; when it is of no further use for this pur- pose it is sold as a fertilizer. In this form, however, it is slowly soluble, and of little prac- tical value. When bone-black is treated with sulphuric acid a much greater per cent, of sol- THE SOIL AS RELATED TO PLANTS. 91 uble phosphate is found than when the mineral, or rock phosphate, is thus treated. In this form it is called "dissolved bone-black," and is a val- uable fertilizer. Other commercial fertilizers containing phos- phorus, with their comparative values, are given in the table. (3) Potassium Compounds. — The potassium in the soil is largely in the form of insoluble sili- cates. The potassium salts of mineral origin used as commercial fertilizers are nearly all ob- tained from German mines ; those most common are the sulphate, muriate, and kainit — a mixture of several salts, as sodium, potassium, and mag- nesium sulphates and muriates. All of these are available for the use of the plant, since they are soluble in water. Pure potassium sulphate contains about 54 per cent, of potassium oxide, but the composition of the commercial article varies, some o-rades containino- not more than 30 per cent. The muriate of potassium (KCl) of commerce contains about 52 per cent, of potassium. Ashes resulting from burning wood, cotton- seed hulls, and tobacco stems contain from 5 to 30 per cent, of potassium carbonate. The amount of potassium carbonate (K^CO,) in ashes depends upon the kind and quality of the wood, the intensity of the heat in burning, and their protection from moisture. Ashes also contain 92 AGRICULTURE. from I to 4 per cent, of phosphates, and from 30 to 40 per cent, of calcium carbonate. Good wood ashes not only furnish available plant-food, but improve the physical condition of the soil. Coal ashes are of no use as a fertilizer. (4) TABLE I. SHOWING THE COMPOSITION OF SOME OF THE PRINCIPAI, COMMERCIAI^ FER'I'II^IZING MATERIALS.* CONSTITUENT. t 1 1 ■2 I. Supplying Nitrogen. Per cent. 15.5-16 19.0-20.5 12.0-14 10 O-II 5.0-6 Per cent. Per cent. Per cent. Per cent. Per cent. Sulphate of ammonia . . Dried blood (high grade) . Dried blood ( low grade) . Castor pomace . ..... 2. Supplying Phosphoric A cid. Bone-black superphos- phate (dissolved bone- black) 3-0-5 I. 0-1.5 17-18 20-25 22-29 15-17 15-17 5-S 6-9 13-15 1- 2 15-17 16-20 2- 3 . 1-1-5 . Ground bone Steamed bone Dissolved bone 3. Supplying Potash Muri'jte of potash .... Sulphate of potash (high 2.5- 4-5 1.5- 2.5 2.0- 3 50 48-52 1 2-12.5 2-8 1-2 5-8 45-48 •5-I.5 33-32 1-2 I-I-5 3-5 Tobacco steins 2.0- 3 The above table shows the comparative values of the most important commercial fertil- izers as food for plants. The amount of these * Adapted from Year-book, 1902, p. 571. THE SOIL AS RELATED TO PLANTS. 93 fertilizers required varies upon different soils and for different plants.* The smallest amounts of direct fertilizers to the acre, which will give satisfactory returns, are ID pounds of nitrogen, 15 pounds of available phosphoric acid, and 20 pounds of potash. By comparison with the above table the amount of the co7iii)iercial fertilizer required may be ob- tained. Exercise 3. — How much nitrate of soda will be needed for an acre if 10 pounds of nitrogen be required? (See Table I.) How much sulphate of ammonia? How much dried blood (high grade)? How many pounds of tobacco stems? How many pounds of phosphoric acid and of potash in tobacco stems which furnislies 10 pounds of nitrogen? How many pounds of bone-black superphosphate will it take to furnish 15 pounds of available pliosphoric acid? How many pounds of insoluble phosphoric acid will this bone-black contain ? How many pounds of sulphate of potash will it take to furnish 20 pounds of potash? How much kainit ? How much (unleached) wood ashes? How much phos- phoric acid contained in the wood ashes ? For indoor plants, again, the amount of the fertilizer must be governed by the kind of soil and species of plant, for what is a "balanced ration " % for one kind of plant is not for another. *" It is unsafe to use chemical fertilizers or liquid manures in full strength on a heavy soil, which is not provided with suffi- cient fibrous material." — Year-book, 1902, p. 558. 94 AGRICULTURE. The following estimate * may be helpful, but practical experience is tJie only safe guide as to which plant-food and how much is needed: Nitrate of soda, 6 to lo ounces, in 50 gallons of water to 100 square feet;f sulphate, or muriate, of potash, 8 to 12 ounces in 50 gallons of water to 100 square feet, or wood ashes, 5 pounds to 100 square feet; calcium superphosphate, i pound in 50 gallons of water to 100 square feet. Whichever fertilizer is needed should be used every ten days, or two weeks, in watering the plants. For mixed, or so-called "complete fertilizer," Voorhees || recommends one-fourth pound of nitrate of soda, one pound acid phosphate, and one-half pound of muriate of potash for 100 square feet. But some think this a little too much. {See also " Plant Improvement.") The kind of fertilizer, as to its slow or rapid availability, to be used depends upon whether the object desired is to slightly enrich the soil for a period of years or to increase the yield of the immediate crop. The time of application would depend upon the kind of fertilizer and the object of its use. * This estimate was given for roses in the Year-book, igo2, and is meant only as an example. f " After the second or third application, a dressing of lime — 5 lbs. to 100 square feet — may follow." — Year-book, 1902, p. 557. \Fertilizers, by Voorhees, p. 327. THE SOIL AS RELATED TO PLANTS. 95 If wanted for the immediate use of the plant, it must necessarily be soluble, and, consequently, should not be applied in the fall but in the spring, when the crop is ready to use it, else it will be leached away and lost. If the more slowly available ones are used, they should be applied in the fall. Hoiu Applied. — Fertilizers must be evenly and thoroughly distributed in the soil. For this reason it is well to mix concentrated fertilizers with dust, ashes, or sand. They may then be scattered broadcast, and plowed or harrowed in, or drilled in. Those which are readily soluble may be simply distributed over the surface, as the rains will carry them into the soil. When sJioiild eominercial fertilizers be used? Not until all home resources are exhaiisted should a farmer buy fertilizers. Proper prepara- ation of the soil by drainage and tillage, attention to rotation of crops, taking care that legumi- nous plants constitute at least one crop in four, so that particular elements will not be exhausted by continuous drain upon them, will do much toward keeping up the yield afforded by the soil. But this is not enough ; all must not be taken out and nothing put in. However, if all waste products on the farm are utilized, there will be little need of expending much money for commercial fertilizers. (5) Lime. — Plants need lime. It tends to 96 AGRICULTURE. make them more compact, and aids in the pro- duction of grain or fruit. Especially is it helpful to leguminous plants, grains, and grasses ; but it is of much less value to corn, and may be even injurious to potatoes, blackberries, redtop, and millet. Lime neutralizes part of the acid in plants forming salts, as the calcium oxalate of beet leaves ; but its most important action is that of an iiidii^ect fertilizer. It benefits the soil as to its physical condition, tending to make clayey soils more porous and light, and sandy soils more compact. Lime changes the chemical constituents of the soil. It is in this action that it brings an increased yield to the immediate crop ; for by chemical action upon organic matter, hastening its decomposition, and upon the insoluble potas- sium and phosphorus compounds in the soil, it renders them available to the plant. While this would tend to produce heavier crops, the con- tinued use of lime, or gypsum, would help to exhaust the soil of its natural plant-food by the increased drain made upon it through the greater yield. Lime neutralizes the acidity of the soil. Through root-action of some plants, or through the formation of acids by the decomposition of organic matter and consequent formation of humous and humic acids, or through the exces- sive use of fertilizers, or by leaching, the soil THE SOIL AS RELATED TO PLANTS. 97 may become so strongly acid in its character as to be unfavorable or unproductive to certain valuable species of plants. This condition may exist not only on swampy or peaty soils, but also upon well-drained soils. Soil may be easily tested for acid by thoroughly moistening it and placing in it a strip of blue litmus paper. If the color of the litmus paper is changed to red the acid of the soil is too strong for plant growth, and the addition of lime will prove beneficial. Another way in which the need of lime in a soil in shown is by the plants which it will nat- urally produce. Plants known to be character- istic of acid soils are : bird's-foot violet ( Viola pedata), wild or beard grass (^Andropogon scopa- riiis), wood-rush (^Liiziila campestris), and, as soon as the soil is cultivated, the common sorrel [Rinnex acetosella), while those plants which are unable to make any satisfactory growth upon such soils are the red clover, lettuce, beets, tim- othy, and spinach.* Exercise 4. — {a) Collect small samples of soil from various places where tlie vegetation might lead one to suspect the presence of acid soil. {U) These samples of soil should be taken from about two to four inches below the surface, and each sample carefully labeled as to exact location from which it was obtained. {c) These samples should be taken to the laboratory, * Roberts' Fertility of the Soil, p. 318. 98 AGRICULTURE. and tested for acid vv'th blue litmus paper. If need be, leave the litmus paper covered in the soil over night. (d) If any soils turn the litmus paper red. the class should visit that particular place, or places, where the acid soils were found, and study the vegetation, making a list of the plants found growing there, and examine the conditions, to discover, if possible, the cause of the acidity. Is the drainage good ? The ventilation ? Is the place densely shaded ? What is the texture of the soil "■ Is it a humous, loamy, clayey, or sandy soil ? Could the conditions be improved? How? (.— REFERENCES. " The Fertility of the Land." Roberts. 1900. 10. " Fertilizers." Voorhees. 1900. 10. " Phosphates." Bulletin 94, Maryland Agricultural Experi- ment Station. " Field Experiments with Nitrate of Soda." Bulletin 164, New Jersey Agricultural Experiment Station. " System of Farm Management." Year-book, 1901. " Relation of Nutrition to the Health of Plants." Year-book, 1901. * " We may take it as a general rule that plants with leathery leaves, with hard and narrow leaves, and with hard wood, re- quire more dilute solutions than those with large, soft, and ex- panded leaves. During the period of leaf formation all plants can do with the greatest amount of nutritive matter." — Vear- book, 1901, p. 172. THE SOIL AS RELATED TO PLANTS. 105 "Soils." Bulletin 41, Minnesota Agricultural Experiment Station. "Chemistry of Plants, Plant Foods, and Soils." Bulletin 94, New York Agricultural Experiment Station. " Fertilizers for Special Crops." Year-book, 1902. " Commercial Fertilizers." Bulletin 99, Vermont Agricultural Experiment Station. " Potash and Its Function in Agriculture." Year-book, 1896. " Soil Ferments Important in Agriculture." Year-book; 1^95. ' Humus in Its Relation to Soil Fertility." Year-book, 1895. o OUTLINE OF CHAPTER V. LEGUMINOUS PLANTS. ^.—LEGUMINOUS PLANTS AS NITROGEN GATHERERS. I. Nitrogen -fixing Bacteria. II. Inoculation of the Soil. III. Other Conditions. ^.—LEGUMINOUS PLANTS AS SOIL RENO- VATORS. I. As Deep Feeders. 1 . Media nica I A ction . 2. Chemical Action. II. For Green Manuring. C— LEGUMINOUS PLANTS AS FOOD. I. High per cent, of Digestible Crude Protein. II. Table of Comparisons. III. Not Lacking in Carbohydrates. Z>.-SPECIFIC CASES. I. Red Clover. II. Crimson Clover. III. Alfalfa. IV. Cow-peas. V. Soy-beans. ^.—REFERENCES. 107 CHAPTER V. LEGUMINOUS PLANTS. From the foregoing chapters the student should have an understanding of the fact that the food of plants must contain certain ele- ments, and that these food elements must be obtained from the air or as soluble material from the soil, so that they can be absorbed by the roots. One of the most important elements is nitro- gen (see Chapter IV^.). It is found in the pro- toplasm of every plant cell. The nitrogenous compounds in the plant, taken as a whole, are called crude protein. No plant can live without a supply of nitrogenous food. Now if this nitrogen is to be obtained from the soil, and since the plant requires so great a proportion of it, it will be easily seen that the supply in ordinary soils would in time be ex- hausted unless some means were taken to replenish it. This is usually done by the appli- cation of a fertilizer — some salt of nitrogen, which is the most expensive of fertilizers. log 110 AGRICULTURE. y^.— LEGUMINOUS PLANTS AS NITROGEN GATHERERS. I. Nitrogen-fixing Bacteria. In recent years it has been discovered (see foot-note, p. 32) that certain plants, through their intimate relation with other low plant forms, bacteria, are able to obtain nitrogen from the inexhaustible supply of the air. The exact relation existino- between these soil bacteria and the roots of leguminous plants is not fully under- stood. But it has been proven by many experi- ments that wherever the bacteria which work upon a particular species of plant are present- — which is shown by the nodules upon the roots (Fig. 31) — the plant is able to make a luxu- riant growth without the addition of nitrogen- ous fertilizers, providing, of course, that other necessary conditions are present. II. Inoculation of the Soil. It sometimes happens that the particular spe- cies of bacteria which works upon a certain species of leguminous plant is not present in the soil. In this case the plant — vetch, for ex- ample — has no nodules upon its roots (Fig. 30), is weak and sickly, and a profitable crop cannot be obtained unless heavy applications of nitrogenous fertilizers are made, which would entail considerable expense, or the soil of this field be inoculated with the bacteria which work FIG. 30. — COMPARISON OF VETCH PLANTS. Grown upon inoculated and uniiioculated soil. 110 i- X^ AGRICULTURE. upon this vetch. This inoculation may be done by a light application of the soil in which these bacteria are known to be. Their presence is indicated by the luxuriant growth of the vetch FIG. 31. — ROOTS OK YELLOW SOY-BEAN. Grown at the Kansas Agricultural Experiment Station in 1896, on land inocu- lated with an extract containing the tubercle-forming bacteria. and the presence of nodules on its roots (see Fig. 30). If any considerable area is to be in- oculated, this method of inoculation is too ex- pensive to be practical, as it requires from 500 to 1,000 pounds of soil to an acre. Recently, through investigations in the labo- LEGUMINOUS PLANTS. 1 L3 ratory of Plant Physiology, the Department of Agriculture at Washington has shown that "the bacteria, when grown upon nitrogen-free media will retain their high activity if they are care- fully dried out and then revived in a liquid medium at the end of varying lengths of time. By using some absorbent which will soak up millions of the tubercle-forming organisms, and then by allowing these cultures to become dry, the bacteria can be sent to any part of the United States or the world, and yet arrive in perfect condition. Of course, it is necessary to revive the dry germs by immersion in water, and, with the addition of certain nutrient salts, the original number of bacteria is greatly in- creased if allowed to stand for a short time. Frequently twenty-four hours are suf^cient to cause the water in a pail to turn milky white with the number of organisms formed in that time. Thus, by sending out a dry culture sim- ilar to a yeast cake, and no larger in size, the original number of nitrogen-fixing bacteria may be multiplied sufficiently to inoculate at least an acre of land. The amount of material thus ob- tained is limited only by the quantity of the nutrient water solution used in increasing the germs. It is evident, therefore, that the cost of inoculating the land is very small." The dry cul- tures may be obtained from the United States Department of Agriculture without cost. 114 AGRICULTURE. " The way in which the Hquid culture may be introduced into the soil varies somewhat with the character of the seed to be used and the area of the field to be treated. With large seed it is often more convenient to simply soak them in the fluid, or moisten them with it, and then, after they are sufficiently dry, to sow them in the ordinary way. In other cases it is frequently more feasible to introduce the liquid culture directly into the soil. This may be done by spraying, or perhaps a simpler method is to mix the culture thoroughly with a wagon-load of earth, and then to distribute and harrow this in, just as a fertilizer would be handled."* III. Other Conditions. It may be possible that some condition of the soil prevents the healthy growth of the species of bacteria. They require an abundant supply of air (see "Tillage") and plenty of moisture, though this should not be present in sufficient quantities to prevent the free circulation of the air. They will not thrive in an acid soil; hence, if difficulty is found in growing leguminous crops, it would be well to give the soil a light application of lime if it is not known to already contain it. * Year-book, United States Department of Agriculture, 1902, P- 341. LEGUMINOUS PLANTS. 115 ^.— LEGUMINOUS PLANTS AS SOIL RENOVATORS. I. As Deep Feeders. Leguminous plants also have the advantage of being deep feeders ; hence, they require a subsoil which they can pene- trate, and alfalfa, in particular, cannot be successfully grown if the soil is underlaid with rock or hard-pan. The roots of these plants thus improve the soil in two ways : 1 . By Mechanical Action they loosen the subsoil, making it more easily penetrated by water, and by subsequently formed roots; and, 2. Chemically, by bringing up from below quantities of the salts of phosphorus and potas- sium, as well as obtaining, through the bacteria, a rich supply of nitrogen from the air. Large amounts of these ele- ments, by the decay of these roots and the stubble, are pre- pared for the use of subsequent crops of surface-feeding plants. a FIG. 32. ALFALFA PLANT. lyong root-system. 116 AGRICULTURE. II. For Green Manuring, or plowing under for fertilizing, the leguminous plants, such as the red, white, or the crimson clover, cow-peas, and soy-beans, are of more value than other crops, since they are compara- tively rich in phosphorus and potash, and fur- nish a supply of nitrogenous compounds, the nitrogen of which is obtained, through their re- lation with certain bacteria, from the air, thus not impoverishing the soil. Green manuring with leguminous plants, while very effective, can hardly be afforded, except for the purpose of building up worn-out, or poor, soil, since legu- minous hay is so valuable as feed (Chapter I.). At the same time more than half of the fertiliz- ing elements may be given back to the soil in stable manure if rightly cared for and applied. C— LEGUMINOUS PLANTS AS FOOD. I. Digestible Crude Protein is absolutely essential to the upbuilding of the tissues of the animal body in repairing broken- down tissues. It has been proven by repeated experiments that a ration which contains a large per cent, of digestible crude protein gives the best results for the least money in the produc- tion of milk, and in contributing to a vigorous and healthful growth of the young. It has been ascertained by analysis, as shown by the follow- ing table of comparisons, that the per cent, of LEGUMINOUS PLANTS. 117 protein contained in the hay of leguminous plants is more than double that in the same weight of the hay of grasses. II.— TABLE OF COMPARISONS.* DIGESTIBI,E NUTRIENTS AND FERTII^IZING CONSTITUENTS. NAME OF FEED. Hay Timothy Redtop Kentucky l.lu^-grass Red clover, :nedium White clover .... Crimson clover . . Alfalfa Cow-pea Lbs. 86.8 91. 1 788 847 90.3 90.4 91.6 893 DIGESTIBLE NUTRI- ENTS IN 100 POUNDS. 2. Lbs. 2.8 48 4.8 6.S II 5 10.5 1 i.o 108 Lbs. 43-4 46.9 37 3 358 42.2 34.9 39-6 38.6 1^ Lbs. 1.4 i.o 2.0 1-7 I..S FERTILIZING CONSTIT- UENTS IN 1,000 POUNDS. ^ ^•^:^ .— SELECTING THE COURSE IN ROTATION. I. What Can Be Successfully Grown ? II. What Can Be Successfully Used or Sold? A— BETTER DISTRIBUTION OF LABOR. i^.— SUGGESTED COURSES IN ROTATION. 6^.— TABLE OF SOILING CROPS. i^.— CATCH, OR COVER, CROPS. /.—KEEPING ACCURATE ACCOUNTS. Exercise 9. /.—REFERENCES. 151 CHAPTER VII. ROTATION OF CROPS. Many of the problems that confront the farmer of the present day might have been avoided had Rotation of Crops been more often ^practiced by our fathers. The productiveness of the soil cannot continue for any considerable length of time unless rotation, or change of crops, is practiced, or fertilizers heavily applied. ^.—INFLUENCE OF ROTATION UPON PLANT- FOOD. I. Preserves Food Supply. I. Prevents Exhaiistion. — Different plants re- quire different proportions of the various foods. If the same crop — as, wheat or cotton — is grown continuously for a number of years, the soil in that field may become so deficient in certain elements essential to that particular crop as to very materially lessen the yield ; while if some other crop, as clover, be sown, the yield may be very heavy, and hence the crop may be more profitable, even at a lower price. Crops should be so selected that different plant-foods — or, at least, different proportions of the plant-foods — will be demanded from the soil each year. 153 154 AGRICULTURE. 2. Prevents Loss by Exposure. — The mate- rials from the soil are not only taken up by the plants, but continuous free and open cultivation exposes the humus of the soil to the sun and to the oxygen of the air, and more of its nitrogen is made soluble than can be taken up by the plants; hence, it is washed out and cariHed away by the rains (Fig. 8). (See under " Cover Crops," p. 159.) II. Increases Food Supply. y 1 . Renders Plant-food A vailable. — Repetition of certain kinds of crops — as, timothy or blue- grass — tends to use up the food faster than it is rendered available, while change of crops and consequent cultivation hastens the breaking up of the chemical compounds in the soil, and thus renders plant-food available. 2. Brings Up Plaut-food from the Subsoil. — The food supply may be further increased by rotating clover, or any legume (all of which have deep-feeding roots), with a crop of corn, or wheat (Fig. 36), which has surface-feeding roots. In this way the deep-feeding roots bring up food elements from the subsoil, and when these roots decay these food materials are ac- cessible to the surface-feeding plants. 3. Facilitates Fertilizing. — Rotation not only prevents the exhaustion of the fertility of the soil, but may be useful in making artificial fer- 155 156 AGRICULTURE. tilizing successful. For example, if stable com- post be applied immediately preceding crops of small grain — as, wheat or oats — it may injure the crop by tending to produce straw rather than grain ; while if it be applied before corn is planted, it will result in an increased yield of corn, and a better condition of the soil for sub- sequent crops (see Fig. 27, "Showing Effect of Nitrate," p. 80). ^.—ROTATION AS AFFECTING THE ENEMIES OF PLANTS. I. Eradicates Weeds. Short rotations with wheat and clover tend to eradicate weeds. If a field becomes overrun with certain weeds — as, the broad-leafed plan- tains — they may be eradicated in a few years by short rotations of winter wheat, or rye, with clover. The clover should be sown upon the wheat early in the spring. The wheat will not be damaged by the weeds, as they do not seed before it is cut, while the same will be true of the clover the following year. The clover stub- ble should be plowed at once to avoid the seed- ing of the weeds. It would then be well to thoroughly prepare the soil and put it in turnips, or some hoed crop, until time to sow the fall wheat, when the ground may be prepared by harrowing. ROTATION OF CROPS. 157 Certain kinds of weeds are found in certain kinds of crops; then, if the field is weedy, this particular crop should not be grown until these weeds are killed out. II. Exterminates Insect Pests. Again, certain crops are more apt to be in- fested with particular insect pests (see " Enemies of Plants"), or fungous (parasitic) plants. If it is known that such enemies have even a start upon a certain field, that crop should not be grown upon it the following year, nor until the pest, whatever it may be, is eradicated. Co- operation of neighbors can greatly facilitate this work. C— PROFIT IN ROTATION. If there is one crop which can be grown upon a field that is more profitable than another crop, it is the first one to be considered in the system of rotation. This crop, however, should not be repeatedly grown, but such a rotation should be chosen as will best fit the grround for the laro-est yield of the best-paying crop. Z>.-SELECTING THE COURSE IN ROTATION. I. What Can Be Successfully Grown ? This will depend upon the kind of soil, the climate, and the seasons. The poorer the soil the shorter the course, and the richer the soil the longer the course of rotation may be. 158 AGRICULTURE. II. What Can Be Successfully Used or Sold? This is another question to be considered in selecting the course in rotation. The answer to this question will depend upon the farmer's facilities for keeping and feeding certain kinds of stock, or upon the location as regards markets for farm crops. ^.—BETTER DISTRIBUTION OF LABOR. Rotation of farm crops not only makes better farms, but it makes better men. In the great grain districts the work requires many men for a short time, and is much less to be desired than to have several successive crops, which distribute the labor throughout the year and enable it to be done by a less number of men, thus making homes and true civilization possible.* A few courses in rotation are suggested below. i^.— SUGGESTED COURSES IN ROTATION. 1. Clover, corn, oats, and wheat. 2. Clover, corn, potatoes, and wheat. 3. Clover, corn, and wheat. 4. Clover and timothy, mixed, two years, corn, wheat, and cow-peas. 5. Cow-peas or clover, cotton, and wheat. 6. Peanuts, cotton, and wheat. 7. For soiling crops : Rye, soy-beans, winter wheat, and clover. Roberts' The Fertility of the Land, p. 369. ROTATION OF CROPS. (7.— TABLE V. SOIIvING CROPS.* 159 CROPS. Seed per Acre. Time of Seeding. Area, Titne of Cutting. Rye Wheat Red clover .... Grass and clover . Vetch and oats . . Vetch and oats . . Peas and oats . . Peas and oats . . Barnyard millet . Barnyard millet . Soja bean Corn 2 bushels 2 bushels 20 lbs. I Yi bu. red top - Yi fiu. timothy ( 10 lbs. r. clover j 3 bu. oats \ 50 lbs. vetch 50 lbs. vetch J i^ bu. Canada I I Y2. bu. oats . . j \Yi bu. Canada 1 iJ4 bu. oats I peck I peck iS quarts Sept. 10-15 Sept. 10-15 July 15-Aug. I I September !■ April 20 April 30 j- April 20 [ April 30 May 10 May 25 May 20 May 20 May 30 I"iy 15 [ Aug. 5 Y acre Y acre Y acre -/i acre Y acre Y acre Y acre Y acre Y3 acre Yi acre Yi acre Yi acre Yi acre Y acre I acre May 20- May 30 June i-June 15 June 15-June 25 June 15-June 30 June 25-July 10 July 10- July 20 June 25-July 10 July 10 July 25-Aug. 10 Aug. lo-Aug. 20 Aug. 25-Sept. 15 Aug. 25-Sept. 10 Corn Sept. lo-Sept. 20 Hungarian . . . Barley and peas . . I bushel j i54 bu. peas '1 i}^ bu. barley Sept. 20-Sept. 30 Oct. i-Oct. 20 The above table of plants used for soiling may be helpful in selecting short crops in a rotation. ^.— CATCH, OR COVER, CROPS. Catch, or cover crops — as, crimson clover, cow- peas, rye, Kaffir-corn, teosinte, and vetch — may often be grown in the time intervening between the principal crops of the year with very little labor and often with much profit. A field which is used in short rotations loses no more of its fer- tility than one which lies idle aud loses its sub- stance by exposure to the weather, or gives it up to weeds. Henry's Feeds and Feeding, p. 233. IGO AGRICULTURE. /.—KEEPING ACCURATE ACCOUNTS. This is as essential on the farm as in the bank or store ; for the farmer should know just what his profit is, and what crops pay best. This can be known only by keeping account of all work done and money expended in putting in and in harvesting the crop, and in the feeding or mar- keting of it. Exercise 9. — {a) Each student should carefully pre- pare an original plan for a course in rotation upon a poor soil, and another upon a fertile soil, in his own vicinity. {/>) Give directions for the preparation of the soil as regards fertilization and tillage. {c) Give directions and reasons for the disposition of each of these various crops. Is it to be fed, or sold ? If fed, in what condition — green or dry? To what ani- mals ? (a) Make an estimate of the probable cost of seed and work, and of the value of the crop ; if sold; if fed ; and calculate the gain. ((?) Read and discuss in class each plan, with reasons. Be able to defend every point taken. /.—REFERENCES. " Practices in Crop Rotation." Year-book, 1902. " The Fertility of the Land." Roberts. 10. " Fertilizers." Voorhees. 1900. 10. " First Principles of Agricuhure." Voorhees. 10. " The Science of Agriculture." Lloyd. 9. " Soils and Crops of the Farm." Morrow & Hunt. 1902. 4. OUTLINE OF CHAPTER VIII. MILK AND ITS CARE. C. H. ECKLES, Dairy Hiishandi y, Missouii Agticitltiiral F.xperiuicnt Slation. ^.— MILK. I. Secretion. II. Care of Milk. 1. Sources of Ahnor»ial Odors. (i) Certain Foods. (2) The Air. (3) Bacteria. 2. Keeping Bacteria Out of Milk. 3. Preventing Gro7vth of Bacteria. (i)'Low Temperature. (2) Pasteurization. III. Composition. 1. Butter Fat. 2. Casein and Albumen. (i) Casein. (2) Albumen. 3. Milk Sugar. 4. Ash. IV. Color. V. Variation in Quantity and Quality. 1. Breed of Animals. 2. Individuality. 3. Period of Lactation. 4. Feed. 5. External Conditions. 6. First and Last Milk Drawn. 7. Intervals between Mil kings. 161 162 AGRICULTURE. VI. The Babcock Test. 1. The Need of a Test for Butter Fat. 2. The Babcock Method. (i) Test-bottles. (2) Pipette. (3) Acid Measure. (4) Centrifugal Machine. (5) Sampling Milk. (6) Making the Test. (7) Reading the Test. (8) Testing Skim-milk and Buttermilk, (9) Testing Cream. Weigh Out Cream for Testing. ^.— CREAM. I. Separation of Cream. 1. By Gravity. (i) Shallow Pans. (2) Deep Setting. (3) Dilution. 2. By Centrifugal Force. II. Ripening Cream. C— BUTTER. I. Coloring. II. Kinds of Churns. III. Churning. 1. Temper at ure. 2. Other Factors Affecting Time of Churning, 3. Wheti to Stop Churning. IV. Washing Butter. V. Salting. VI. Working. VII. Composition of Butter. VIII. Overrun. IX. Packing and Marketing. Z>.— REFERENCES. CHAPTER VIII. MILK AND ITS CARE. C. H. ECKLES, Dairy Husbaiidtv, Missouri AgricuHuia/ Expefinieni Station. ^.— MILK. I. Secretion of Milk. Milk is a tluid secreted by the mammary glands of all animals that suckle their young. It contains all the elements of nutrition neces- sary for the nourishment of the young animal in a palatable and easily digested form. The material forming milk is all taken from the blood, but changed in nature by the secret- ing cells so that no constituent of milk, except water, is found in the blood in the same form. In the wild state the cow only gave milk enough to nourish the calf until it could subsist on other food. Under domestication of the cow the secretion of the milk has been greatly increased by careful selection and liberal feeding. II. Care of Milk. The conditions under which milk is handled are of the greatest importance, whether it be used as food or manufactured into butter or cheese. I. Sources of Abnormal Odors. — Milk begins to decompose and possesses abnormal odors 164 AGRICULTURE. and tastes after standing for some time, and occasionally these are present when it is milked. There are three common sources of these ob- jectionable tastes and odors in milk. (i) Certain Foods, — When food eaten by cows contains any strong volatile substance, this will be carried througrh the circulation of the cow and into the milk. For example, when a cow eats onions, turnips, or even some strong weeds, the characteristic odor and taste may be recognized in the milk. These odors may be mostly driven off by heating the milk. Ordi- narily very little trouble is experienced from this source, as the common feeds have no notice- able effect on the flavor of the milk. (2) The Air. — Any odors, even if not very pronounced, may be readily absorbed from the air by milk or butter. Milk exposed to the air of an ill-kept barn, or a musty cellar, often ab- sorbs odors that make it very objectionable for food. (3) Bacteria. — The most common cause of objectionable tastes and odors of milk is the action of various bacteria. Bacteria of many kinds are found in milk, and various kinds of fermentation result from their action. In addi- tion to common souring, milk may be decom- posed, giving off bad odors, may become ropy, or bitter, or even have an abnormal color due to the action of bacteria. MILK AND ITS CARE. 165 Most of the bacteria found in milk are perfectly harmless, al- though at times those causing diseases, such as typhoid fever, diphtheria, and tuberculosis, may get into the milk. It is impossible to keep all bac o o o °\ o9 O ° OoOo c " o ° o^o ^Q „ r. O ^O o^^ °vj o ^ - o OO ^ o o O teria out of milk, q' ,^ \ ^ VQ N but a great deal % '• ,^0 x\» #^'Q done to- oQi.A:;.Pct)Y- keeping Q I'/A^oV^^'^QV- can be ward k them o keeping those that do get in from growing (Fig- 37)- •-^o'.y-o^^^ it v^x.• ' > • » 2. Keeping Bac- teria OiLtof j\Iilk. — This process may be summed up in one word — cleanliness. The bacteria (Fig. ■^'j) get into milk with dust particles from many sources, but the most n « B Fir.. 3/. PUKE AND IMPURE MII.K HIGHLY MAGNIFIED. ,-1, pure milk; /?, after standing in a warm room for a few hours in a dirty dish, showing, be- sides the fat globules, many forms of bacteria. 166 AGRICULTURE. common and the worst contamination usually takes place in the barn. Very often the stable is not kept clean, the body of the cow becomes soiled, and, during milking, dust particles from the hair become loosened and drop into the milk-pail. The milker may wear dirty clothes, and the air of the barn may be full of dust, or the milk-vessels may not be perfectly clean. The number of bacteria in the milk can be greatly reduced by observing the utmost clean- liness in every particular, especially about the barn, during milking, and by cleansing the uten- sils thoroughly. All milk-vessels should first be rinsed out with cold water, as hot water coagu- lates the albumen and makes it stick to the ves- sels. After this rinsing, they should be thor- oughly scalded and sunned to kill any bacteria present. 3. Preventing Growth of Bacteria. — Next in importance to keeping bacteria out of milk is preventing those that do get in from growing rapidly. (i) Low Temperature is the chief factor to be relied upon. If it is desired to keep milk sweet for some time, it should be cooled at once after milking to 50° F., or lower if possible. If this is done, and this temperature maintained, milk will remain sweet several days, while if it is allowed to remain warm it will sour within twenty-four hours. MILK AND ITS CARE. 161 FIG. 38. — PASTEURIZING APPARATUS. (2) Pasteurization.— Another method of preventing the growth of bacteria in milk is that of Pas- t eurizatio n (Fig. 38). This consists in heating milk to about 160° F. for twenty minutes, then rapidly cool- ing to 50° F. This kills about 99 per cent, of the bacteria, and the keeping quality of the milk is very much improved. III. Composition of Milk. The milk of all mammals contains practically the same constituents, but varies greatly in the proportion of each. The average composition of cow's milk in America is as follows : Water, 87.5 per cent.; fat, 3.6 per cent.; casein, 2.9 per cent.; albumen, .5 per cent.; milk sugar, 4.75 per cent.; ash, or mineral, .75 per cent. I. Butter Fat. — The butter fat is commer- cially the most valuable part of milk. It varies in amount more than any other constituent of milk except water. Wide variations from the average composition are constantly found. Fat seldom is less than 2.5 per cent., or more than 108 AGRICULTURE* 7 per cent. Butter fat is found in milk in the form of minute drops of oil, called globules. These globules vary in size from xijoTi to -^ohnr of an inch in diameter (see A, Fig. t,"/). The number present in even a small amount of milk is beyond comprehension. This fat is made up of a mixture of ten or more distinct oils, the more important of which are stearin, pabnatin, oleiu, and butyrin. The first two mentioned melt at a temperature above 140° F., while olein is liquid at 32° F. The hardness of a certain lot of butter depends upon the proportion of these oils present. Green food, such as grass, increases the proportion of olein, and accounts for the soft condition usually observed in butter made during- the summer months. Butyrin is the characteristic fat of butter, and is found only in butter fat. The chemical dif- ference between butter and oleomargarine is largely the absence of butyrin in the latter. The size of the fat globules (Fig. 37) in milk varies with the breed of the cow, the feed, and with the individual animal. It is of some im- portance on account of the relation it bears to the separation of cream and to churning. Large fat globules separate from the milk and form cream more quickly than do small ones, and with somewhat less loss of butter fat in the skim-milk. Cream composed of large fat glo- bules churns more rapidly. MILK AND ITS CARE. 169 2. Casein and Albiuncn. — These constituents vary less in quantity than does butter fat. They are very similar in composition, and serve the same purposes as food, but differ widely in ap- pearance. They differ from other parts of milk by containing sulphur, nitrogen, and phos- phorus. (i) Casein. — This constituent of milk may be seen as the curd which forms when milk sours. It is present in milk in a very finely divided con- dition in combination with lime. When milk sours, the acid unites with the lime, and the casein then becomes insoluble, and appears as the common curd of sour milk. When milk is used for butter-making, the most of the casein remains in the skim-milk, some goes into the buttermilk, and a small amount into the butter, making upon the aver- age I per cent, of the latter. Casein is an important part of cheese, com- posing approximately one-third of common cheese. (2) Albumen. — This substance, as found in milk, is practically the same as the white of an ^'g'g. It differs from casein in being entirely in solution, making about .5 per cent. When milk is heated to i6o°F., or above, the albumen is coag- ulated, and is seen as a tough scum on the sur- face. When milk is used for butter-making, the 170 AGRICULTURE. most of the albumen remains with the skim-milk and buttermilk. In cheese-making albumen re- mains in the whey, and is not incorporated into the cheese. The very disagreeable odors char- acteristic of decomposing milk are largely pro- duced from albumen. J. Milk Sugar. — This sugar, known by the chemist as lactose, has the same composition as common cane sugar (CijH^^OjjH^O), and is found only in milk. It appears, when separated, as a fine white powder, with a mild, sweet taste. Milk sugar is a common commercial article, be- ing usually secured from whey as a by-product of cheese-making. When milk is used for butter- making almost all the sugar remains with the skim-milk and buttermilk, while in cheese-mak- ing it remains in the whey. Its chief impor- tance in butter or cheese making is its relation to the souring of milk or milk products, which is due to the decomposition of the sugar through the action of minute forms of plant life called bacteria. By this act of decomposition, lactic acid is produced from the sugar, and this gives the common sour taste and causes the precipita- tion of the casein, as seen in soured milk. 4. AsJi. — This is the portion that would re- main if milk were burned. It consists of a mix- ture of several elements, the most important being lime, iron, potash, magnesium, sulphur, and phosphorus. These mineral matters are all MILK AND ITS CARE. 171 in combination with the casein and albumen, and make up about .7 per cent, of average milk. IV. Color. The normal white color of milk is mostly due to the casein. The yellow shade observed in varying degrees is due to a specific coloring matter called lactochrome, which is combined with the butter fat, and gives butter the natural yellow color. The amount of this coloring mat- ter varies greatly, being affected the most by the feed of the cow, but also by breed and in- dividuality of the cow. Green feeds, as grasses, give the highest color, while dry feeds, as hay and grain^ the least color. The Guernsey and Jersey breeds produce the highest colored milk and butter; the Holstein and Ayrshire the lightest colored. The yellow color of milk is often taken as an index of its richness, but this cannot be relied upon, and is of little value as a means of judging the quality of milk. V. Variation in Quantity and Quality. I. Breed. — Certain breeds of cows are charac- terized by producing rich milk, and others by pro- ducing unusually large quantities. The breeds that produce rich milk produce a less quantity, on the average, than do those producing the poorer quality. In order of ricJiness, the com- mon breeds stand as follows : Jersey, Guernsey, Short Horn, Red Poll, Ayrshire, Holstein. The Holstein breed stands considerably ahead in FIG. 39. — A GUERNSEY COW — CHARMANTE OF THE GRON I4442. ADV. R. NO. 74. Test, 11,874.76 pounds milk; 676 pounds fat. Florhani Farms, New Jersey. FIG. 40. — -A JERSEY COW IMP. JKRSKY VENTURE I22508. A. J. C. C. 8285, J. H. B. F. S. I,one Tree Herd, Greensburg, Ind. MILK AND ITS CARE. 173 amount of milk, followed by the Ayrshire, Guern- sey, and Jersey. 2. Individuality. — The difference between in- dividual animals in the same breed is greater than the average difference between breeds, both as to quality and quantity of milk pro- duced. This factor should be given first con- sideration in estimating the value of an animal for dairy purposes. 3. PciHod of Lactation. — By period of lacta- tion is meant one complete milking period, usually from nine months to one 3^ear. A cow, as a rule, produces the most milk per day within a month after the calf is born, and gradually de- creases in amount until the secretion ceases. The lowest per cent, of butter fat usually is found at the time of greatest production, and increases somewhat as the flow of milk de- creases. 4. Feed. — The kind and amount of feed have great influence on the quantity of milk pro- duced, but have no effect on the per cent, of butter fat, although it is believed otherwise by many dairymen. The richness of a cow's milk is as natural to her as is the color of her hair, and is affected about as little by change of feed. 5. External Conditions. — Many other things affect the quality and the amount of milk se- creted — as, treatment by milker, change of FK;. 41. — AN AYRSHIRE COW — VIOLA DRUMMOND. 10,000 pounds of luilk in 365 days ; test, 3.9 per cent. fat. Riverside Stock Farm, Woodville, N. Y. FIG. 42. — A HOLSTEIN COW. Owned by M. E. Moore, Cameron, Mo. 174 MILK AND ITS CARE. 175 weather, sudden fright, milking at irregular in- tervals, and sickness. 6. First and Last Milk Draum. — The first milk drawn from the udder at any milking is much poorer in quality than the last. The first often tests as low as i to 1.5 per cent, fat, and the last 8 to 9 per cent. fat. 7. Intervals between Milkings. — When the in- tervals between milkings are equal in length, the morning and night milk is usually about the same in quantity and quality. When the inter- vals are not equal, the larger amount, but the lower per cent, fat, follows the longer interval VI. The Babcock Test. I . Need of a Test for Butter Fat. — M ilk varies greatly in richness. The writer once tested the milk of a herd of cows each day for a year. The milk of one cow averaged 2.7 per cent, butter fat ; that of another, 7 per cent. The variation in milk from different herds, although less ex- treme than the case mentioned, is found to be very marked ; hence, to do justice to all, milk is now bought or sold at wholesale, as a rule, by the test. The creamery or cheese factory pays a cer- tain price for each pound of butter fat as ascer- tained by the test, and not for the gallon or hundredweight of milk. This does away with all temptation to milk adulteration by watering or skimming when selling by the test. Milk 176 AGRICULTURE. sold at retail in cities is required in most places, either by state or city law, to contain not less than a certain per cent, of butter fat — usually 3 or 3.25 per cent. Problem. — A owned a cow giving milk which averaged 2.7 per cent, butter fat. B owned a cow giving milk averaging 7 per cent, butter fat. C bought one gallon (8.4 pounds) of milk of A daily, from March ist to September ist, at 6 cents a quart. D bought milk of B for the same time, buying the same amount daily, at the same price per quart. If butter fat was worth 25 cents per pound at the cream- ery, how much did D gain by buying milk of B instead of A for the six months named ? Did he pay more or less than the milk would have sold for by the test, sup- posing that a gallon of the milk weighed 8.4 pounds? How much ? Another and possibly the greatest value of the test is as a means of enabling the farmer to judge which cows are profitable and which are not. The writer once fed two Jersey cows standing side by side the same kind of feed and practically the same amount to each. During the year one produced 145 pounds of butter, the other 428 pounds. The farmer should take into account not the per cent, of butter fat alone, but the amount of milk and the test together. The following is the record of two cows in the same herd: Pounds Pounds Per cent. Milk Butter Butter Fat No. I 12,111 538 3-81 No. 2 6-523 532 7.00 MILK AND ITS CARE. 177 In this case it will be observed that the rich- ness of the milk alone is not a fair means of judging the value of the two cows, neither is the amount of milk alone. 2. The Babcock Method. — The method gen- erally used for finding the amount of butter fat in milk and its products is known as the Bab- cock test, and has done more to revolutionize the dairy industry than any other invention ex- cept the centrifugal cream separator. This method was invented by Dr. Babcock, of the Wisconsin Experiment Station, in 1890. It is an accurate, rapid method for finding the per cent, of butter fat in milk, cream, skim-milk, butter- milk, whey, or cheese. In this system sulphuric acid is used to dissolve the solids other than fat in milk, and the fat is then separated by centri- fugal force, and measured on a graduated scale. The apparatus includes the following (Fig. 43) : test-bottles, 17.6 centimeter pipette, acid meas- ure, sulphuric acid, and a centrifugal machine (Fig. 44). (i) Test-bottles. — The test-bottles are made of strong glass, to withstand sudden changes of temperature. On the neck is a scale graduated from o to 10. Each whole di- vision represents i per cent., and is subdivided into five divisions, each one reading .2 percent. By estimating between divisions, the reading of the test may be made to . i per cent. 178 AGRICULTURE. g i J 1 cr FIG. 43. — GLASSWARE FUR BABCOCK TESTER. a — Measuring pipette, b — Milk-testing bottle, c — Cream-testing bottle d — Acid measure. (2) Pipette, — The basis of the test is 18 grams of milk. Asa matter of convenience, the amount is measured and not weighed. It is found that a pipette holding 17.6 cubic centi- meters to the mark delivers 18 grams of milk. The pipette is filled by suction of the lips, and MILK AND ITS CARE. 179 the top of the pipette closed with the fore- finger. (3) Acid Measure. — This holds 17.5 cubic centimeters, and is usually made in the form of a cylinder with a base. The acid used is that known as commercial sulphuric acid, having a specific gravity of 1.8 1 to 1.83. If the acid be a little weak the fact will be known by white sediment appearing under the fat column, and this may be remedied by usinga little more acid in another test. If the acid be too strong it will be indicated by the column of the fat being blackened and having black sediment below. This can be remedied by using somewhat less acid. Acid very much stronger or weaker than the standard does not give satisfactory results. (4) Centrifugal Machine. — Many forms of machines are made, varying in capacity from two to forty test-bottles. The smaller (Fig. 44) are made for use in small dairies, and run by hand ; the larger ones are used in factory work, FIG. 44. — HAND-POWER BABCOCK TESTER. This style is made especially for farm use. 180 AGRICULTURE. and are run by steam-power. The bottles should always be arranged so that the machine will be balanced before running- it. The speed at which these machines are to be run depends upon the size of the revolving wheel, but the rim should, as a rule, move from 60 to 70 feet per second. (5) Sampling Milk. — In testing milk the greatest care is necessary to get a fair sample of the lot to be tested. The entire amount should be poured from one vessel to another several times if possible, or, if this cannot be done, it should be stirred thoroughly from top to bottom. Many errors are made by not secur- ing the correct average sample. (6) Making the Test. — (a) Mix the milk thoroughly, and measure sample into test-bottle, (d) Add measure of acid by pouring carefully down side of bottle held at slight angle from perpendicular.* {c) Mix thoroughly by shaking with a rotary motion until the liquid be- comes an even chocolate brown color. (^) Run in a centrifugal machine five minutes at correct speed, (c) Stop and fill to base of neck with hot water or distilled water, 150" F. or above. (/) Whirl 3 minutes, then fill with hot water to 7 or 9 per cent. mark, (g) Whirl 2 minutes and make reading. (7) Reading the Test. — -Care must be taken to keep the contents of the test-bottle hot and the fat entirely liquid. It is at times necessary * Care should be taken not to allow the acid to come in contact with the fingers or clothing. MILK AND ITS CARE. 181 to place the bottle in hot water between whirl- ings before making the reading. The reading of the fat column is taken from the extreme top to the extreme bottom. (8) Testing Skim-milk and Buttermilk. — The operator of a butter or cheese factory should keep close watch on the losses of butter fat in the skim-milk and buttermilk by making frequent tests. For testing these products exactly the same method is used as described for testing milk, except a special kind of bottle, having two necks, is used, which allows finer readings to be made. Each small division on these bottles reads .05 of i per cent., and by estimating readings can be made to .01 of i per cent. (9) Testing Cream. — It is far more difficult to make an accurate test of butter fat in cream than in milk. Cream varies greatly in amount of butter fat present, ranging from 12 or 15 per cent, to 60 per cent, of butter fat. As the milk test-bottle only reads to 10 per cent., it is neces- sary to have a special testing-bottle for cream where much testing is to be done. Cream can be tested in ordinary milk test' bottles by adding two measures of water to one of cream, then testing the mixture in the same manner as for milk, multiplying the reading by three. When the common cream test-bottles are at hand which read to 30 per cent., the 17.6 182 AGRICULTURE. milk pipette may be used and the testing carried out the same as with milk, except only about three-fourths the usual amount of acid is used. If the cream has more than 30 per cent, of fat it cannot be read on the scale on the bottle. U nder these circumstances one measure of cream and one of water may be mixed together, and a test made of the mixture, doubling the readings. Weio-h Out Cream for Testing. — The fore- going- methods of testing cream are accurate enough for some purposes, but when cream is bought and sold by the per cent, of butter fat the amount of cream taken as a sample for test- ing should be zueighcd out and not measured. The measuring of cream introduces several errors which cannot be discussed in detail here, but all tend to make the result of the test too small. The chief error affecting accuracy of measuring cream is the difference in specific gravity of cream and milk. The i 7.6 c.c. pipette delivers 18 grams of milk, but as cream is lighter than milk, does not deliver 18 grams of cream. To avoid all these errors, small balancers are used, and 18 grams of cream weighed out into the test-bottle. i)'.— CREAM. I. Separation of Cream. Cream is that portion of milk into which most of the fat globules have been gathered. It has the same constituents as milk, but in a different MILK AND ITS CARE. 183 proportion, due to the large amount of fat present. Cream is separated from milk for food pur- poses, and as a matter of convenience and econ- omy in making butter. Butter can be made, and is made in some countries, by churning milk. Cream may contain from 12 to 60 per cent, of butter fat. Cream as sold at retail usually has from 18 to 20 per cent., and a very rich cream has from 35 to 45 per cent, of fat. The apparent thickness of cream is not a reli- able means of judging its real quality. Cream is separated from milk by taking advantage of the difference in specific gravity between the fat globules and the remainder of the milk. We have two general systems of separating cream. Both take advantage of the difference in specific gravity already mentioned. I. By Gravity. — If milk be allowed to remain undisturbed in a vessel of any kind, the fat glob- ules, being slightly lighter than the other con- stituents, gradually rise to the top. This is the oldest and, until recent years, the only method of separation in use. There are two methods of gravity creaming in common use : shallow pans, and deep setting. (i) Shallow Pans. — Although the oldest and least effective in every way, this is still the most common method used in many localities. As generally used, the milk is placed in shallow 184 AGRICULTURE. pans or crocks, kept at a rather low tempera- ture, as in a cellar, until the cream has risen. It is then skimmed off with a flat skimmer. The conditions most favorable for this system is a layer of milk not over four inches deep and cooled rapidly to a temperature of about 60° F., and allowed to stand 36 hours before skimming. This separation of the cream is not very com- plete by this method, and in this respect it ranks lowest of all systems used. On an average, about one-fourth of the butter fat is lost in the skim-milk when using the shallow pans. The quality of cream for butter-making purpose is also the poorest. On account of the large sur- face exposed to the air during the rising of the cream, any obnoxious odors of the atmosphere are readily absorbed, and this exposure also makes conditions favorable for the formation of strong, undesirable tastes in the cream and but- ter. Cream from this system is in condition for food purposes only when skimmed off much sooner than would be done when used for butter- making. (2) Deep Setting. — The deep-setting system consists in placing the milk in cans about twenty inches deep and six inches in diameter (Fig. 45), set in water which should be kept at 40° F., or below, for twelve to twenty-four hours. At the end of this time skimming is done by using a conical dipper, or drawing off first the skim- 186 AGRICULTURE. milk and then the cream from a faucet in the bottom of the can (Fig. 45). This system is in general use in some localities, and with general satisfaction. The deep setting ranks, both in thoroughness of separation and quality of cream for food and butter-making, next to the centrifugal separator. Under proper con- ditions, by its use 80 to 90 per cent, of the butter fat should be secured in the cream. The cream from this system is rather low in but- ter fat, as a rule testing from 18 to 20 per cent. fat. (3) Dilution. — Within recent years an old plan of diluting milk with cold water has been revived, and devices for using this method have been sold very extensively in many places under the name of "water separators," "aquatic sep- arators," etc. The general plan is to add cold water equal in volume to the milk. Instead of ranking with the cream separator, in whose name they are wrongfully given, they rank with the shallow pan in thoroughness of separation. As a rule, from 20 to 50 per cent, of the butter fat is lost in the skim-milk. The diluted condition of the skim-milk is another disadvantage. The quality of the cream is better than that of the shallow pan, and it is more convenient. 2. By Centrifugal Force. — The centrifugal separator (Fig. 46) has revolutionized the dairy industry within recent years. The first centri- MILK AND ITS CARE. 187 fugal separators were put in practical use in Europe about 1879, but were not in general use until ten years later. At present they are considered indispensable BOWLOPEN KH;. 46. — A MODERN HAND-rOWER CREAM SEPARATOR. This separator has a capacity of 450 pounds of milk per hour. The bowl on the right generates the centrifugal force by revolving rapidly. to the successful dairyman. In the separator the centrifugal force generated by a rapidly re- volving bowl takes the place of gravity and acts with a force very much greater. The milk flows into the revolving bowl (Fig. 46) in a continu- 188 AGRICULTURE. ous Stream, while the cream flows from one opening and the skim-milk from another. As the milk flows into the revolving bowl, it is acted upon by centrifugal force, and fiies to the outside wall of the bowl. The skim-milk, being heavier than the cream, is forced outward with greater force, and seeks the outside of the bowl, forcing the lighter cream toward the cen- ter. Near the outer edge of the bowl are open- ings of small tubes, into which the skim-milk flows and through them passes out of the bowl. Near the center of the bowl is the opening of a small tube, which carries out a constant stream of cream. A number of conditions affect the thorough- ness of separation with a centrifugal separator, especially the speed of machine, the tempera- ture of milk, and the rate of inflow of milk. The most favorable temperature for separating milk is from 85° to 100° F. When the temper- ature falls much below 80°, the loss of butter fat with the skim-milk begins to increase. Some types of separators are much more sensitive to low temperature than are others. The proportion of the milk taken out as cream can be changed in most separators with- out changing the thoroughness of separation by slightly turning what is called the cream screw. By this means most separators may be adjusted to separate from 10 to 50 per cent, of MILK AND ITS CARE. 189 butter fat. The centrifugal separator should remove about 98 per cent, of the butter fat in the form of cream. The cream from the sepa- rator, being removed while the milk is sweet, is in the best condition for food or for butter- making purposes. Separators vary in capacity from 150 to 4,000 pounds of milk per hour. Problem. — A farmer feeds lo hogs 5 gallons (42.5 pounds) of skim-milk daily from June ist to December ist. What will be his loss, supposing that butter aver- aged 18 cents per pound, and he sells his hogs for $5.00 per hundred pounds, if he separated his cream by the gravity process — (a) With shallow pans ? (d) With cans 20 inches deep? (c) If he used the centrifugal separator? {d) By which method of separation would he lose most, and how much more than by each of the other two methods ? II. Ripening Cream. It is a well-known fact that milk which is al- lowed to stand in a warm place for a few hours begins to sour and finally coagulates. This is a process of fermentation, and is due to the growth of an immense number of living organ- isms called bacteria. These bacteria are not in the milk when it leaves the animal body, but gain access from many sources, such as unclean utensils and dust from the air. The souring fermentation is undesirable in milk to be used for food, but is a necessary part 190 AGRICULTURE. of making the best butter. The consumers of butter prefer that it have the peculiar taste which is characteristic of butter made from soured or fermented cream. Butter churned from sweet cream is insipid in flavor and is not desired by many; furthermore, it does not keep as well as that from soured cream. For these reasons cream is allowed to sour before being- churned into butter. This condition is usually brought about within twenty-four hours or less by leaving the cream moderately warm, usually from 60° to 70°. The most approved method is to add what is called a starter, to cause the desired kind of souring to begin. This may be likened to the use of yeast in bread-making. When the proper condition of sourness is reached the cream is ready for churning. This stage is detected by taste and appearance, or in factory work by an accurate test. The condition may be described as a mild, sour taste, and a somewhat thickened or granular appearance of the cream. C— BUTTER. I. Coloring Butter. The natural color produced, when cows are on fresh grass, is the standard butter color. This shade should be maintained throucrhout the year, and this requires the use of artificial coloring part of the time. Coloring made for this purpose is a common article in the markets. MILK AND ITS CARE. 191 The best coloring used in butter is made from annotto, a vegetable product, and is entirely harmless. There can be no objection to color- ing butter, as it deceives no one and pleases the eye of the consumer. Butter without artificial coloring is almost unsalable in most markets durinof the winter months. The colorine-matter is added to the cream before churnine- The coloring-matter is dissolved in an oil which unites with the fat of the butter and does not color the buttermilk. II. Kinds of Churns. A large number of churns have been invented, but none is better suited for the small dairy than the common barrel churn (Fig. 47). Churns with dashes, or other means of agitating the cream violently, are objectionable, on account of loss in churnincr and effect upon the quality of butter. Within recent years a new type of churn, called " com- 1 . 1 1 , 1 M I-'IC. 47. — BARREL CHURN. bmed churn and worker. Adapted for farm use. has been put on the market. These churns are now used almost exclusively in large butter factories, and in many dairies. As the name indicates, this machine churns the cream, and later works the butter in the same apparatus. 192 AGRICULTURE. III. Churning^. Churning is the gathering together of the fat globules into a mass called butter. This may be accomplished by any kind of agitation violent enough to cause the fat globules to come together with some force. I. Effect of Temperature. — One of the most important factors to be considered in connection with churning is the temperature. Temperature controls, to a large extent, the time of churning, the loss of butter in the buttermilk, and that important quality of the butter called the grain. The higher the temperature of the cream the softer the butter fat becomes, and the more readily it unites, shortening the time of churn- ing. The temperature should be so regulated that the time required for churning will be be- tween one-half hour and one hour. No definite temperature can be given as applicable to all cases, as it must vary somewhat with the thick- ness of the cream, season of the year, and period of lactation. The best rule is to churn at as low a temperature as it is possible to have the butter form within the desired time. Butter factories, as a rule, churn cream from 50*^ to 54*^ F, in summer and from 54"^ to 58° in winter. (Smaller dairies usually churn at somewhat higher temperature.) The greatest improvement that could be made at a small expense in the method of butter- making^ on the averagfe farm would be the use MILK AND ITS CARE. 193 of a thermometer, and a proper control of the churning temperature. Butter churned too warm lacks firm texture, and is said to be "weak bodied" and softens easily in a warm tempera- ture. Churning at too low a temperature re- sults in unnecessarily lengthening the time of churning, with no advantage gained in the con- dition of the butter. 2. Other Factors Affecting Tiine of Churn- ing. — The per cent, of butter fat has an impor- tant bearing upon the time of churning. A cream with a low per cent, of butter fat churns more slowly than does a richer cream, and re- quires a higher temperature. Cream from cows that have been giving milk a long time churns harder than cream from fresh cows, and requires a somewhat higher churning temperature, as the butter fat of the former is harder, the globules smaller, and the milk more viscid or sticky, mak- ing it more difficult for the fat globules to ad- here togfether. Cream from cows producing large fat glo- bules churns a trifle easier than does that from those producing small ones, and maybe churned at a lower temperature. Cream produced from dry feed churns more slowly than that produced from green feed, and should be churned at a higher temperature, on account of the hardness of the fat and more vis- cid condition of the milk. 194 AGRICULTURE. 3. When to Stop ChiLvning. — Churning should be stopped when the butter granules are about the size of larofe orrains of wheat. Churnino- until the butter is p-athered into a mass, as is often clone, makes the removal of the butter- milk impossible, resulting in poor keeping qual- ity and injured grain of the butter, IV. Washing Butter. When churning is completed and the butter- milk removed, the next thing to be done is to wash the butter. For this purpose clean, cold water, at a temperature somewhat colder than that at which the cream was churned, is used About two-thirds as much water as there was cream is added to the butter, and the churn re- volved slowly for six or eight turns. It is then stopped and the cold water drawn off. The ob- ject of washing is to remove the buttermilk from the butter. V. Salting. Butter is salted as a matter of taste. The amount of salt used may vary somewhat, but, as a rule, it is from three-quarters to seven- eighths of an ounce to each pound of butter. The salt used should be of the best quality, and made especially for this purpose. The act of mixing the salt with the butter is known as working the butter. MILK AND ITS CARE. 195 VI. Working Butter. The objects of working are to expel a portion of the water, to mix thoroughly the salt with the butter, and to get the butter into compact, mar- ketable form (Fig. 48). The combined churn and worker runs the butter between slowly revolving rollers, and is used almost exclu- sively in large butter factories. The work- ingr is continued until the salt is evenly dis- tributed and the grain "g. 48.— farm dairy butter- /. 1 T 1 WORKER. 01 the butter shows ^ ,,, u .. ^ One of the best tor farm use. the right stage has been reached. At this stag^e the (granules of butter almost lose their identity and string out slightly when the butter is broken, instead of breaking straight across. Overworking butter spoils its grain, and insufficient working results in uneven or streaked color of the butter, known as mottling. The latter is a very common and a very objectionable fault in butter. VII. Composition of Butter. The average composition of butter is about as follows : Fat, 85 per cent.; casein, i per cent.; salt, 2.5 per cent.; water, 11.5 per cent. The composition varies considerably, espe- cially the fat and water. Butter of good quality 19G AGRICULTURE. seldom contains less than 80 per cent, of fat or more than 15 per cent, of water. VIII. Overrun. The term "overrun" is used to express the excess of butter made over the amount of butter fat contained in the cream or milk. The Bab- cock test shows the amount of pure butter fat. When this is made into butter, water, salt, and casein are present, in addition to the fat. Under the best conditions of handling, the butter should exceed the butter fat about one-sixth, but may vary greatly. The common method of estimat- ing the yield of butter from the Babcock test is to find the total number of pounds of butter fat, and add one-sixth of its weight. This is the plan used by experiment stations and dairymen keeping records of the production of individual cows. IX. Packing and Marketing. After the butter is thoroughly worked, it is next packed in form for market. The style of package will vary with the market for which the product is intended. When large quantities are to be shipped some distance, various sized tubs (holding from ten to sixty pounds) are used. These tubs are made of ash or spruce, and the sides are lined before use with a piece of parchment paper, a circle of the same being placed in the bottom of the tub and another on the top. For local sale, various 198 AGRICULTURE. packages are used — as, different sizes of wooden pails, glass or earthen jars, and paper boxes; but the one most favored is the rectaneular pound print wrapped in parchment paper. These are made rapidly by means of molds de- signed for the purpose, and when once adjusted print very accurate pounds (Fig. 49). Z:*.— REFERENCES. " Dairying at Home and Abroad." Year-book, 1902. " Utilization of By-products of the Dairy." Year-book, 1897. "Care of Dairy Utensils." Year-book, 1896. "Care of MilR on the Farm." Farmers' Bulletin 63, United States Department of Agriculture. " Facts About Milk." Farmers' Bulletin 42, United States Department of Agriculture. " Feeding the Dairy Cow." Bulletin Missouri Agricultural Experiment Station. " Milk and Its Product." Wing. 1900. 10. " Testing Milk and Its Products." Farrington & Woll. 1900. Mendota Book Co., Madison, Wis. " Dairy Bacteriology." Russell. 1899. Madison, Wis. " Butter Making on the Farm." Farmers' Bulletin sy. "Milk as Food." Farmers' Bulletin 74. OUTLINE OF CHAPTER IX. PROPAGATION OF PLANTS. ^.—PROPAGATION FROM SEEDS. SEP.US AND SEEDLINGS. I. The Seed-coat. Str.Jifictition. II. The Testing of Seeds. 1. Jmpo' taiice of Seed-testing, 2. Purity. 3. Vitality. Factors influencing vitality are : (i) Time of Gathering. (2) Condition of Parent Plant. (3) Age (4) Method of Preservation. (II. Germination of Seeds. A stiui}" of tiie conditions for germination 1. 'xei.iperaturc. 2. Moisture. 3. Atr. 4. Geotropisni. 5. Light. 6 Otiier Conditions. IV. Treatment of Fine Seeds. V. Variation of Plants. 1. Causes of Variation. (1) Difference in Food Supply (2) Climatic Conditions. (3) Sexual Reproduction. 2. Fixation of Variation. (i) Means. {a) Natural Selection. {b) Artificial Selection. 199 200 AGRICULTURE. (2) Time Depends Upon: (a) Tendency of the Plant to Vary. {l>) Rate of Development. ^.—PROPAGATION FROM BUDS. I. Cutting. 1. Green IJuwd Ci/ flings. (i) Leaf Cuttings. (2) Stem Cuttings. 2. Hard-wood Cuttings. (i) Stem Cuttings. (2) Root Cuttings. II. Budding. 1. Spring Budding. 2. Late Slimmer or Early Fall Budding. III. Grafting. General principles of. Subdivisions of. 1. With Reference to Position of the Scion Upon the Stock. (i) Root-grafting. {a) Whole-root Grafting. {b) Piece-root Grafting. (2) Stem-grafting. {a) Top-grafting. {b) Crown-grafting. 2. With Reference to Insertion of Scion Into the Stock. (i) Tongue or Whip Graft. (2) Cleft Graft. IV. Layering. 1. Simple Layering. 2. Mound Layering. 3. Pot Layering. C— REFERENCES. CHAPTER IX. PROPAGATION OF PLANTS. The basic principle of all horticultural opera- tions is a thorough hiowledge of tJie plant and its environment. This necessitates a careful study of the nature and conditions of the seed- ling- throughout its development from the em- bryo to the adult plant. ^.—PROPAGATION FROM SEEDS. SEEDS AND SEEDLINGS. I. The Seed-coat. Examine the outer covering of a number of dif- erent seeds — as, the corn, bean, squash, peach, canna, and locust — noting carefully the difference in their textures. If these seeds be planted at the same time and under the same conditions, they will show equally as great variations in the time which they require for germination. In nature, the hard, tough seeds of many or- chard and forest trees — as, apple, peach, and hickory — are buried beneath the litter of the orchard or forest, where they are subjected to winter snows and changes of temperature until their outer coverings are softened or cracked, so that the embryonic plant may develop, while the seeds of such species as the catalpa (Fig. 50), honey-locust, and Kentucky coffee-bean re- 203 AGRICULTURE. main on the trees all winter. This indicates that a cold, moist ground would be disastrous to them ; consequently, these seeds are shed in the warm days of spring, the higher temperature unsealing the waxy covering of the honey-locust, and the spring winds widely disseminating the delicately winged seeds of the catalpa. By fol- lowing these hints of nature, man may perform and regulate these processes almost at will. Sir atiji cation is a very practical and simple method of preparing many seeds having a hard or tough outer covering for germination. By this means the seeds are protected from mice, chipmunks, squirrels, etc., and at the same time given the conditions furnished by nature. Directions for stratifying seeds: {a) In October or November take the seeds of cherry, apple, peach, plum, hickory, and walnut, which have been collected during the summer and autumn. [b) Place, in a shallow box, a layer of sand, leaf- mould, or even garden soil, then a layer of the seeds; in this way alternate a layer of sand with one of seeds until the box is full. [c) Sink the box in the ground in some shady place, and leave uncovered, exposed to the winter snows, rains, and frosts until the following spring. [d) When the weather permits, plant thickly in rows in well-prepared soil. (See " Tillage.") II. The Testing of Seeds. I. The Iinportance of Seed-testing prepara- tory to planting, and the simple methods by which it may be done, are not generally realized. FIG. 50. CATALPA TREE. Showing seed pods intact in February. 204 AGRICULTURE. Often many annoyances and disappointments would be averted, and much time and labor saved, if proper attention were given to the quality of the seeds sown. Bad seeds not only result in partial or total failure of the crop, but may be the means of introducing noxious weeds — as, the plantains. A field is frequently sown in bracted plantain when it was meant to be sown in red clover. The principal points to be considered in determining the quality of seeds diVe. pitrt^y and vitality. 2. Purity. — Various impurities may exist, either incidentally, or purposely, in commercial seeds — such as inert matter, or seeds of other useful or injurious plants — any of which would make the seeds more expensive if not altogether objectionable. Purity of seeds may be tested by carefully examining with the eye — or lens, if necessary — a fair sample of the seeds to be planted. 3. Vitality of Seeds. — In the testing of seeds it is not safe to rely upon general appearances — such as form, color, and odor — but the seeds must be actually tested to be certain of their vitality. Experiment 15. — [a) From each kind of seeds de- sired, select at random a certain numben according to the quantity to be planted. (J)) If the seeds are large, it may be advantageous to soak them a few hours. PROPAGATION OF PLANTS. 205 (c) Saturate several thicknesses of heavy blotting- paper, and fit them into shallow flats or plates ; now place the seeds directly upon this moist paper. (If very fine seeds, put them upon squares of cheese-cloth spread upon the paper.) Cover the flats with pieces of window- glass, leaving crevices to admit air. Each day note carefully, and remove the number of seeds which sprout. {d) What per cent, of seeds was vital ? What does the ti///e required for sprouting indicate regarding their vitality? Could the same results be expected from out- door conditions? Would a farmer be justified in plant- ing the seeds from which these samples were taken ? Does not this test warrant the revision of the old adage, "Taste and try before you buy," to "Test and try be- fore you buy," in this case ? Factors influencing- the vitality of seeds are : (i) The time of gathering; (2) the condition of the parent plant ; (3) the age of the seeds, and (4) the method of their preservation. Experiment 16. — (a) Take seeds of several garden or farm crops — as, wheat, corn, beans, peas, radishes, let- tuce, and apples — which have been gathered at intervals during the growing season, so that two stages (imma- turity, maturity) in the development of the seeds may be represented. (d) Note the date of gathering, the appearance of the seeds, and the condition of the parent plant at each of these stages. (c) Plant those of each stage in a separate row and label the rows. (d) Observe, compare, and tabulate the time of appear- ance of each seedling. {e) From your results in this experiment, what effect do you conclude the ^t'me of gatherijig has upon the vital- 206 AGRICULTURE. ity of seeds ? Why ? Wliat effect has the condition of the parent plant upon the vitalit)'^ of tlie seeds? (3) Age of Seeds. — For the success of the following experiment time and patience are the chief requisites. The work may be begun in one class, and continued by each successive class as long as any of the seeds show vitality, or some student may elect this work through- out his school course. Experiment 17. — () Divide each kind into two lots. Plant one of these g08 AGRICULTURE. lots (each kind at the proper depth) in a box of sand; the other lot place in a shallow dish of water, and soak for ten or twelve hours; then plant these seeds in the sand at the same depth and under the same conditions as the first lot. (c) Note and tabulate the time of the appearance of the seedlings of the soaked and unsoaked seeds of each kind. (d) Was the time of germination of each kind short- ened by the soaking? Were any seeds damaged by soaking? Experiment 20. — (a) Select seeds, as in the above ex- periment. Soak one-half of each kind, as before. (b) Now separate the soaked and the unsoaked seeds each into three lots. (c) Plant one lot of each (the soaked and unsoaked) in dry soil, another in moist soil, and the third in wef soil, other conditions being the same for each. (d) Tabulate, and compare results. (e) What does this experiment teach concerning the condition of the soil with regard to moisture at the time of planting seeds? 3 ^^'^■ Experiment 21. — (a) Fill a pot with moisf sand or mellow garden soil, and another pot with clay or loam that has been 7oet and well stirred until about the con- sistency of paste. Now plant in each pot several beans, peas, or grains of corn, pressing them in and carefully smoothing over the top. {b) Place both pots under the same external con- ditions. If the puddle clay or loam cracks, moisten it, and again press the surface smooth. {c) Observe and note results. What fills the inter- stices in the jar of moist sand or soil ? What in the puddled clay? Do the seeds in each pot germinate PROPAGATION OF PLANTS. 209 equally well ? Why? What condition is present in one pot that is not in the other? 4. Geotropism. Experiment 22. — {a^ Plant in moist sand or sawdust a number of squash seeds and grains of corn in various positions — some with either side down, some with either edge down, and some with either end down. {b) Label each group as to position in planting. {c) After two or three days, examine to see if any of the seeds have sprouted. (. Flower or fruit bud. to the open ground as soon as the weather per- mits. Where this is not practicable, they may re- main packed in the sawdust until favorable weather, and placed at once in the open ground, which has been prepared by deep plowing and thorough pulverizing. ('. stipule scar. d. Leaf scar. ^.Growth of one season. ./. Two-year-old wood. FIG. 66. — TWIG OK WHITE ELM {Ultmts Americana, X,.) 328 AGRICULTURE. ( r fc> *5' \ / mal Garden.) cleft-grafting. The tongue or whip graft is used for both piece and whole root grafting. Directions for root-grafting : {ci) Hold the stock or scion vvliicli is to be cut in the left liand, with the end supported by the index finger. 234 AGRICULTURE. (^) Now make a diagonal cut through the base of the scion or the top of the stock, as the case may be. While still holding it in this position, beginning one-third of the length from the outer end of this cut, make a verti- cal slit about an inch long. {c) When the stock and scion are each thus prepared, H FIG. 75. — STEPS IN ROOT-GRAFTING. carefully insert the tongue of the one into the slit of the other in such a manner as to bring the cambium layer of the stock into direct contact with that of the scion (Fig. 75), and wrap closely with No. 18 knitting cotton or moist rafifia. (d) Cut this wrapping into foot lengths, and, begin- ning at one end of the grafted parts, pass the thread several times around, allowing one end of the thread to be held beneath this wrapping. Now pass the thread on up to the other end of the graft, and wrap again, this time fastening the free end of the thread by slipping it firmly between the projecting and the united parts of the graft, as in Fig. 75. This grafted stock when com- pleted should be about eight or ten inches long. PROPAGATION OF PLANTS. (ress the soil closely about the. roots, allowing but one bud to re- main above the surface. As a rule, they should be allowed to grow two years before being transplanted to the orchard, during which time clean cultivation should be given throughout the growing seasons. (2) Stem-grafting. — In stem-graft- ing, old or otherwise undesirable trees are used as stocks. (a) Top-grafting. — The metJiod of grafting used most often in this work is the cleft-graft, on account of the large size of the stocks to be grafted. For good results, however, the branches used as stocks should not be much over one and one-half inches in diameter. It would be too great a shock to fig. 76.— dor- the tree to remove all of the old top '^^'^'^^ apple r TWIG. in one season; consequently, a por- 1,2, 3, 4 are scions '■ ^ ^ which may be cut tion of it should be grafted each ^a^^respecdveiy.' ^' 236 AGRICULTURE. successive season, for three or four seasons, until the entire old top has been replaced. Directions for top-grafting: (a) Time. This work should be done in the spring, just before, or about the time, the buds open, or even later, /r6'7^/V/^ keep out air and moisture. Grafting-wax is made by breaking into small pieces two to two and one-half parts (by weight) beeswax and four to five parts resin, and melting them together with one part of tallow or linseed oil. The greater the pro- portion of resin and beeswax, the harder the grafting- wax will be. When this mixture is melted, pour it into cold water. As soon as it is cooled enough to handle, remove the wax from the water and pull like taffy until it becomes light colored. It may be applied with the fingers, if the hands have been carefully greased, or ap- plied with a little stick while the wax is hot, if care be taken not to injure the parts waxed. (<^) Crown-grafting. — This method is gener- ally used for shrubs, grape-vines, etc. Directions : In crown-grafting tlie stock is prepared by cutting off the plant at the surface of the ground. The process is th.e same as that of top-grafting, the only difference being t\\G position of the graft. IV. Layering. This method of asexual reproduction differs from that of cuttingr buddinor, and eraftinp-, in that the new plant is rooted while still attached to the parent plant. This is not only the sim- plest, but also the most certain, method of bud propagation wherever practicable. In nature familiar examples of layering are the black rasp- berry (Fig. 55), strawberry, and dewberry. In fact, very many plants will send out roots if brougrht in contact with moist soil. 238 AGRICULTURE. I. Simple Layering. — Directions for layering : {a) This is ordinarily done by merely bending down any one of the lower side shoots, placing it in a slight depres- sion, pegging it down with a forked stick, and covering it with a few inches of mellow soil. In a dry season it will be necessary to moisten this soil, and mulch it with dry earth or grass. {p) Under favorable conditions roots will form at the buried node, and a new plant may be secured by separat- ing the rooted shoot from the old plant. If more than one plant is desired, bury as many nodes as the old plant will sustain. 2. Mound Layering. — A very simple process called mound layering is practiced where a num- ber of new plants are desired from a single parent. Directions for mound layering: {a) The parent plant is cut off at or near the surface of the ground before growth begins in the spring, and is called the " stool." By the following spring many shoots will have been produced. {h) The stool and the base of the shoots are mounded up with soil to the depth of several inches. Roots will be formed at the underground nodes of these the same summer (Fig. 78). (r) In autumn, or the following spring, the newly rooted shoots maybe removed from the stool and trans- planted as individual plants. (^/) The same stool may be repeatedly used, if well cared for by thorough cultivation and liberal applica- tions of stable compost. Any low, stubby plants — as, the gooseberry, or even the quince — may be advantageously propagated by mound layering. PROPAGATION OF PLANTS. 239 Wherever the process of layering cannot be performed by bending the branch to meet the soil, the soil, or a substitute, may be lifted up to the branch. There are various devices used in doinof this. 3. Pot Layering. — (i) The limb which has been par- FIG. 78. — MOUND LAYERING. tially girdled in order to check the backward flow of sap is surrounded by some moist material — as, sphagnum moss, vegetable fiber, or soil. This should be held in place by merely wrapping the moss or fiber closely about the wounded portion of the stem. This wrapping should form a ball about five or six inches in diameter, so that it will not dry out too quickly. This may be further protected by an additional covering of a heavy paper cone. (2) Instead of the moss or fiber, layering pots contain- ing soil may be used. (a) A simple form of layering pot may be con- trived from a tomato-can by cutting a hole in the bottom of the can slightly larger than the stem to be inclosed ; then make a slit down one side of the 240 AGRICULTURE. can and lialf-way across the bottom to the hole in the center. {/>) Carefully spring the can far enough apart to admit the limb (which should be well wrapped with cloth just where it is encircled by the bottom of the can, to keep it from being cut), and adjust it so that the girdled portion will be in about the center of the can. {c) Wrap the can securely in both directions with wire, and support it by attaching the wire to an upper limb {(f) Now fill the can with moist soil, and see that it is kept moist. (e) When the soil is filled with roots cut off the stem below the can, prune back the top, and transplant where desired. An ingenious teacher may contrive many simple de- vices for layering by using such material as is at hand, as, chalk-boxes, etc. (3) Where several layers are to be obtained at one time from a tall shrub or small tree, a long, box of soil may be supported by a post beneath the twigs to be layered. These must be pegged down in the soil until rooted. For any particularly desirable bud variation (" sport") this plan is especially advantageous. C— REFERENCES. " Top Working Orchard Trees." Year-book, 1902. "The Superior Value of Large Heavy Seed." Year-book, 1896. "Testing Seeds at Home." Year-book, 1895. " Seed Selling, Seed Growing, and Seed Testing." Year-book, 1899. "The Propagation of Plants." Farmers' Bulletin 157, United States Department of Agriculture. " The Apple and How to Grow It." Farmers' Bulletin, 113. " Plant Propagation." Circular No. 13, Missouri Agricultural Experiment Station. PROPAGATION OF PLANTS. 241 " Orchard Technique." Bulletins 98, 99, 100, and loi, Virginia Agricultural Experiment Station. "The Apple Orchard." Bulletin 49, Missouri Agricultural Experiment Station. " Orchard Management." Bulletin 59 Illinois Agricultural Experiment Station. " The Principles of Plant Production." Circular No. 15, Mis- souri Agricultural Experiment Station. " Principles of Plant Culture." Goff, 1899. Published by the Author, Madison, Wis. " Principles of Agriculture." Bailey. 1900. 10. "Garden-making." Bailey. 1898. 10. "The American Fruit Culturist." Thomas. 1897. William Wood & Co., N. Y. "Propagation of Plants." Fuller. 1887. Orange Judd Co., N. Y. " New Creations in Plant Life." Harwood. 10. OUTLINE OF CHAPTER X. IMPROVEMENT OF PLANTS. Basis of : 1. Variation. 2. Heredity. 3. Selection. y^.— IMPROVEMENT OF EXISTING TYPES, I. Selection of Seeds. 1. Table of Standards. 2. A Study in the Selection of Seeds. II. Isolation of Seedlings. III. Given Normal Conditions. IV. Selection Should Be Repeated. V. Example of Type Improvement. ^.—ORIGINATING NEW VARIETIES. I. Determining the Ideal. 1. Definite Characteristics. 2. Characteristics Chosen Along the Natural Develop nient. 3. Characteristics Must Harmonize witli Eacli Other. (i) Earliness. (2) Size. (3) Number. i. One Leading Characteristic. 243 244 AGRICULTURE. II. Variation Furnishes the Starting-point 1. Variation of Scealiiigs. 2. Variation may be induced by — (i) Environmental Changes. {a) Change in Food-supply. {h) Light Relations. {c) Pruning. (2) Cross-fertilization. {a) Limits of Crossing. {b) Varying Results of Crossing {c) Process of Cross-pollination 3 Bud Variation. III. Fixing the Type. C— REFERENCES. CHAPTER X. IMPROVEMENT OF PLANTS. '* Those who improve plants are true benefactors." GOFF. Variation, heredity, and selection form the basis of all plant improvement. 1. Variation. — It is evident that the first re- quisite toward the improvement of plants must be the power to vary ; for were it not possible for plants to vary, no change could take place. It is these individual differences that make one plant more desirable than another, and thaty>/r- nish the starting-point for the improve7nent of the existing type, or for the origination of a new variety. 2. Heredity. — While variation furnishes the starting-point, the desired characteristics would be of no avail in plant improvement were it not possible for them to be transmitted by heredity. 3. Selection. — By continued selection through a number of generations, the characteristics fur- nished by variation are preserved and accumu- lated through heredity. yi.— IMPROVEMENT OF EXISTING TYPES. When the object desired is simply to improve a given variety, individual plants can be found 245 246 AGRICULTURE. in any field or garden crop which are especially good representatives of the existing type. I. Selection of Seeds. The very first thing to be done is to select the most perfectly developed seeds from those particular plants which most nearly conform to the standard of perfection for that type, Agricultural Kipuriuieiit Station, Ames, luwa. FIC. 79. — VAKIATION IN GRAINS OF CORN. No. I is liLst since the grains are full and plninp at the tips next the cob, and have large germs indicating strong vitality and feeding value. Nos. 2, 11, and 12 are the next best forms in order. Nos. 5, 6. and 7 are weak, with low feeding vahie and small percentage of corn to cob. Since the grains are fio/ uniform in size, the planter will not drop the same inimber in each hill. These grains were taken from ears that appeared to be good when examined from the standpoint of the ear, and shows the importance of paying more attention to the selection of grain from the seed ears of corn. Exercise io. — A Study in Corn Judging. — {a) Procure a half-bushel of mixed or unimproved corn and ten or twelve ears of an improved variety of corn. {b) Judge and score the improved or standard variety of corn according to the points and directions on the score card. (<:) Judge and score the mixed corn. (^ 7!4-7/^ St. Charles Yellow lo-i i 7/4-8 Boone County White lo-i i 7/4-8 Farmers' Interest lo-i i 7/4-7M St. Charles White 9-10 7-7^^ Silvermine 9-9/4 7-7/4 Cartner ^Vz-gVi 7-7 -^^ Student's Name. Date. 248 AGRICULTURE. HOW TO APPLY THE POINTS OF THE SCORE CARD. Uniformity of Exhibit. (IS) — The ears of an exhibit should be uniform in size, color and indentation. The 15 points allow 5 to be given for size, 5 to color, and 5 to indentation. Each ear may be cut as much as one- half point under each of these heads. For each ear that is larger or smaller than the prevailing type cut one-fourth to one-half point. For each ear of different shade or color from the prevailing type cut one-fourth to one-half point. For each ear that differs in indentation from prevailing type cut one-fourth to one-half point. The sum of these cuts gives the total cut of uniformity of exhibit. Maturity and Marlcet Condition. (10) — Each ear should be solid and free from injury or decayed soots. Each ear showing a marked degree of looseness should be cut not to exceed one point. For ears less imperfect in this respect a cut of one-fourth to three-fourths may be made. Ears showing rotten spots or injuries should be cut one-fourth to one-half point each. Purity — Kernels. (5) — Kernels should be free from mixture with corn of opposite color. Mixture in yellow corn is shown on caps of kernels in white corn on the sides. For each mixed kernel in an ear cut one-fourth point. Purity — Cobs. (5) — Cobs should be of one color; in yellow corn, red; and in white corn, white. (Except St. Charles White.) For each cob of opposite color cut 2 points. For pink cobs cut one-fourth to one-half point, according to shade. Two cobs of opposite color shall bar exhibit. Shape of Ear. (10) — Ears should be as nearly cylindrical as possible. A cylindrical ear usually means a greater jjer cent of corn to cob and a larger number of kernels of uniform size and shape for planting. Cut one-fourth to one point for each ear that tapers too greatly. Proportion of Length to Circumference. (10) — The ratio of length to circumference should be as 4 to 3, or the circumference measured at a point one-third the distance from butt to tip should be three-fourths the length of the ear. Cut one point for each ear markedly out of proportion. Shape and Uniformity of Kernels. (10) — The ideal kernel is slightly wedge-shaped but not pointed, the length of which is approximately one and one-half times as great as the width at the widest part. For each ear showing kernels of poor shape, or kernels which are larger or smaller than the prevailing type, cut one-fourth to one point. Should an ear have ker- nels deficient in both uniformity and shape cut two points. Character of Germ. (10) — Germ should be full, smooth, bright, not blistered, shriveled, or discolored. When broken it should show a fresh, brit- tle, oily appearance. Cut not more than one point for each ear showing inferior germs. Butts. (5) — An ideal butt on an ear of corn should be well-rounded out, with deep, regular kernels, solidly and evenly compacted around a clean cup-shaped cavity. Cut not to exceed one-half point for each de- fective butt. Tips. (5) — The tip should be filled out to the end with deep kernels in regular rows. The ideal tip is completely covered, but if kernels are deep and regular to end of cob no cut need be made. Cut not to exceed one-half point for each tip. Space Between Rows. (5) — Furrows between rows should be narrow but not entirely closed. Cut not to exceed one-half point for each ear seriously deficient in this respect. Per Cent of Corn to Ear. (10) — The per cent of corn to ear should not be under 84. A high per cent of shelled corn is desirable, but too small cobs do not favor a large yield of corn per acre. Cut not to exceed one point for each ear markedly deficient in this respect, or where the sample is shelled and weighed, cut one and one-half points for each per cent which the sample averages below 84. IMPROVEMENT OF PLANTS. 240 proved corn and compare them with the improved vari- ety of corn. How do they compare as to per cent, of corn? How many of the best ears of your improved corn would it take to make a busliel (56 pounds) of shelled corn? How many of the best ears of tlie mixed corn would it take? Do you know wliich yields the more per stalk? Which requires the more ground to grow a bushel of shelled corn ? Which requires the more seed to plant the ground ? Which requires the more labor to produce the bushel ? Which, then, is the more economical and profitable kind to grow? II. Isolation of Seedlings. The selected seeds should be planted In a place where they will be isolated from other plants of the same or of a different variety with which they would readily mix, else they would be contaminated by their neighbors ; for if they were not isolated from other individuals of the same variety, they would probably mix with in- ferior ones, and the improvement would, there- fore, be less. For this reason, also, it would be well to weed out from the seedlings of the selected seeds all inferior plants before the pollen ripens. If these selected seeds were planted near a different variety, the two varieties might mix, and the resulting offspring, in all probability, would not conform to the type. * It may seem to some that undue importance is placed upon the details of this study. But comparatively few persons realize the bearing of careful, intelligent selection upon the improve- ment of the agricultural products of America. 250 AGRICULTURE. III. Given Normal Conditions. The seedling's should be kept tifider normal conditions, for any variation in the conditions would have a tendency to induce variation in the plant (see " Variation," p. 214). IV. Selection Should Be Repeated from generation to generation, so that these type characteristics may be transmitted, accu- mulated, and fixed ; thus will result the improve- ment of the type. V. Example of Type Improvement. As an example of the improvement of the existing type may be given the Boone County white corn improved by Mr. James Riley, of Indiana. He took for his type a fine white sort, selecting seed from the best-formed plants bear- ing one or two well-formed ears. He con- tinued this selection for a nuniber of years. In addition to this he went through the fields just as the tassels were appearing and cut out all imperfect and barren stalks. In this way the type was improved, as is shown in Fig. 80. * i?.— ORIGINATING NEW VARIETIES. I. Determining the Ideal. I. The first step in originating a new variety is to determine definitely the characteristics which one ivishes to develop in the new plant. * Let each student prepare a definite, original, feasible, plan for the improvement of some promising existing type which needs improving. IMPROVEMENT OF PLANTS. 351 Fir,. So. — IMl'KOVEMENr UF CORN liY SELECTION. Boone County white on left, and the original type from which it was developed by selection on right. 2. These desired characteristics must be chosen along tJie line of tJie natural development of the plant. In this way not only is the time lessened in reaching the desired variety, but the attainment of that variety is much more nearly certain. 3. These charactci'isties ninst be in Jiaj'nwny with eaeh other. (i) For example, if earliness is especially desired, size must not be expected, as in the earliest varieties — for example, sweet corn — the size not only of the ears but of the whole plant is much reduced. 352 AGRICULTURE. (2) If size is desired, time and number must often be sacrificed. As Emerson says, "For everything you have missed, you have gained something else ; and for everything you gain, you lose something." The Ponderosa tomato is a good example of increased size at the ex- pense of number. A single plant bears about a dozen immense tomatoes. (3) If number is to be increased, then size must necessarily be diminished. Of this the little preserving tomato affords a good example. A single plant sometimes yields several hundred tomatoes. 4. There should prevail one leading charac- teristic. Continued selection should be made with this predominating character in mind. If high flavor is the one character most desired, then all other characters must be made subor- dinate. In case other desirable qualities are found combined with high flavor in the same plant, as is often the case, it would then be ad- vantageous to breed from that plant. For ex- ample, in breeding for high flavor in the straw- berry, those plants should be chosen which possess the highest flavor, other characters being given secondary consideration ; but if individual plants can be found which combine both qualities, prolificacy and flavor, it would, of course, be advisable to propagate from those particular plants. IMPROVEMENT OF PLANTS. 253 II. Variation Furnishes the Starting-point. 1. Variation of Seedlings. — When the charac- teristics of the desired variety have been defi- nitely determined, then if one will diligently and carefully search among his plants, he may find — owing to variation — individuals which possess these characters in a more marked degree than do the others. But if such individuals are not found, then 2. Variation maybe induced hy (i) Environ- mental Changes. Important among these is («) a change in food-supply. Darwin says: "Of all the causes which induce variability, excess of food, whether or not changed in nature, is probably the most powerful." If heavy foliage and rank-growing plants rep- resent the " ideal," they should be given a liberal supply of nitrogeneous food (see " Effect of Nitrogen," Chapter IV.) If dwarf size and fruitfulness are the desired characters, then foods containing potash and phosphorus should be substituted. Experiment 26. — {a) To show variation induced bv change of food supply. Secure one-half bushel of pure white sand, and sterilize^ it by thoroughly baking it in a hot oven. {b) The tomato, geranium, etc., are suitable plants for this experiment. Select three small, similarly developed plants grown from cuttings of the same stock (see page 220). ^54 AGRICULTURE. (c) Pot these plants in similar-sized small pots, re- potting as tlie sand in each pot becomes filled with roots Place them under similar conditions as regards light, air, temperature, and water. Label the pots i, 2, and 3. {(/) Prepare stock solution No. i, containing the es- sential elements of plant-food in approximately the proper proportions, by thoroughly pulverizing and dis- solving in 1,000 parts of water (say \,oooc. c.) 15 parts monocalcium phosphate, 20 parts potassium sulphate, 2 parts magnesium sulphate, 30 parts sodium nitrate, and 2 parts sodium chloride — adding a few drops of some soluble iron compound. Prepare stock solution No. 2 in every way like No. i, except that you leave out the sodium nitrate. Prepare stock solution No. 3 similar to No. i, except that you leave out the potassium sulphate. (The mineral matter will not entirely dissolve, so these solutions should be well shaken before using.) {e) When watering plant No. i, occasionally add a definite amount of solution No. i. (The condition of the plant must be the guide as to the time and amount of this food-supply.) Begin with a small amount, and gradually increase or diminish it. \t the same time add to the water used in watering plant No. 2 the same amount from stock solution No. 2, and to that used in watering plant No. 3 add the same amouni of stock solution No. 3. (/) Measurements and observations should be taken at stated times during several months upon the follow- ing points: Number, size, and color of leaves of each of these plants; hight and mean circumference of their stems; number and size of branches; time of flowering; number and character of blossoms; and in the tomato, the number, size, and quality of fruits. Experiment 27. — If for any reason the above experi- aient is not practicable, substitute (a) ordinary soil (no' i: p. « w=3 256 AGRICULTURE. rich soil) for the sand; select the plants, and label the pots as in above experiment. [b) When watering the plant in pot No. 2, add a small but definite amount of water leeched from wood ashes; when watering the one in pot No. 3, add the same amount of water leached from stable compost; when watering pot No. i, add the same amount of each. As above, the condition of the plants must determine the time and amount of the food-supply. {c) Make the same observations and comparisons as in Experiment 26 (/). (Ji) Light is another factor in inducing vari- ation among plants. Light, in some degree, is essential to the growth of all green plants. Hence, all such plants strive to adapt themselves with reference to their light relations — (a) in the arrangement of their leaves by the rosette habit (Fig. 81), as in the plantain and dande- lion; (^) in the manner of branching and leaf- arrangement of trees; (r) in the elongation of and direction of the stems, as in the trees and vines of a dense forest; or (rt^) by turning to- ward the light, as in the sunflower. Experiment 28. — The student should be required to make actual observations and measurements of the variations of plants for adaptation to light from those plants of the same kind grown in the light and in the dark.or partial darkness. Experiment 29. ■ — Let him try to produce a volublej stem by starting some erect plant — as, the potato or tomato — in a darkened place, so arranged that light is admitted only from one small opening (about three inches square) at one side and above the plant. When it IMPROVEMENT OF PLANTS. 25^ has made a growth of several inches, place a round, straight stick in the pot for its support, and bind it to it with a soft string, leaving about two inches of the top of the plant free. When this free portion has bent directly toward the light, gradually turn the pot so that as the tip again turns toward the light the stem will at the same time make a par- tial revolution around the support. (Fig 82). Continue turning the pot in this manner throughout the growth of the plant. As the plant develops, it would be well to give it more light, but this should always be obtained from a northern exposure. (f) Variation Induced by Pruning (Fig. 83). — Not only is the food-supply distributed to a less number of branches, thereby increasing the amount to each branch, but the form of tJic en- tire plant can be greatly modified by prtining. Buds or branches may be ac- cidentally destroyed or intention- voiuwe stem pro- ■^ ■^ >. duced by Experi- ally removed. As an example of ment 29. variation induced by accident may be given the origination of the Burpee Bush Lima bean. In 1883 " Mr. Palmer's entire crop of large White Pole Limas was destroyed by cutworms." KIG. 82. — POTATO TLANT. 258 AGRICULTURE. He found one little plant which had been cut off about an inch above the ground, and had put out a new growth, "It bore three pods, each containing one seed.'"'' These were planted the next spring, resulting in two dwarf plants. From these, by continued selection, the Burpee Bush Lima was de- veloped. Sutryfestion : If the school does not own a garden plot, the teacher should secure a vacant lot by paying a small rental, or, perhaps, by sharing the products. If this is not possible, then the work of pruning and cross-pollina- tion must be done by those members of the class who can have access to private gardens, and their results reported to the class. If it is desired to secure a stout, bushy plant, instead of a tall, single-stemmed one, let the student take the chrysanthemum or cosmos for example. FIG. S3. MODIFICATIDNS UF COSMOS BY PRUNING. * Bailc-y's Plaul-Hi fiuiiug , page 139. IMPROVEMENT OF PLANTS, 259 Experiment 30. — (a) As soon as the terminal bud has become quite distinct, it should be removed. (/^) The development of lateral branches should be carefully watched and their terminal buds removed. (r) This should be continued at will, according to the form of the plant desired (Fig. 83). Experiment 31. — If size of blossom or of fruit is de- sired, all but a few of the flower buds should be removed, allowing tliose which are most advantageously situated in regard to light and food supply to remain. The chrysanthemum or cosmos will afford good mate- rial for this experiment with reference to size of blossom, while the tomato will furnish excellent material with regard to size of fruit. The modifications of the plant and the bene- fits to be derived from the various methods of pruning will be further discussed under the gen- eral subject of pruning. (2) Variation may be induced by Cross-fer- tilization. It may be possible that no plant can yet be found which combines the essential characteristics of the " ideal." In that case it would be advisable to select two plants, each of which possesses one or more of these characters, and to try to combine these in one plant by means of cross-fertilization. The Trophy tomato well illustrates the com- bination in one plant of the desired characters of two separate plants. In 1850, Dr. Hand, of Baltimore County, Maryland, desired to ur.ite the large size and firm fiesh of the compound, much convoluted tomato with the smooth skin 260 AGRICULTURE. of the small, juicy Love Apple. By cross- fertilization " he succeeded in putting the solid mass of this compound growth into the smooth skin of the Love Apple, and then, by careful selection and cultivation year after year, in- creased its size and solidity until it became a mass of flesh interspersed with small seed cells." Another good example is that of the varie- gated hybrid carnation produced by crossing the pink variety (Scott) with the white Mc- Gowan (see colored plate). (rt) Limits of Crossing. — The two plants to be crossed must be members of the same family 2nd of species, or varieties which are in some way closely allied. But even among these it is impossible to determine, without actual experi- ment, just what plants will cross with each other. This uncertainty of crossing among plants is exemplified in the case of the pumpkin {Ciicur- bita pepd) and squash {Cnciirbita maxima), which are species of the same genus, yet will not cross.* While with the strawberry and rasp- berry, which belong to different genera, a cross has been obtained. {J)) Varying Results of Crossing. — Even when a fertile cross is obtained, it may not show the desired characters in the first generation. f It '*' Year-book, 1897, p. 389. f " The first generation is constituted by plants grown from the seeds produced by the cross-pollinated flowers." — Year-book, 1897, p. 392. IMPROVEMENT OF PLANTS. 261 should be borne in mind that " the possibilities are by no means exhausted, but it is quite pos- sible that the descendants of these hybrids will yield valuable sorts." In many cases the cross, or its descendants, may possess the desired characters of one parent, while those desired from the other parent may be entirely lacking. In that case "it would be advisable to cross the offspring with that parent * whose characteristics did not appear; for, by so doing the tendency to transmit those particular characters will be increased, for this tendency is itself variable.""}* At the same time, the individual plants of the original cross should not be discarded for sev- eral generations, for there is in the offspring a slight atavisticj tendency, or a tendency to re- vert to the character of some remote ancestor; hence, at any time an individual plant may appear which presents the very characters desired. In no instance can the plant-improver afford to neglect any condition or advantage which will tend to induce the desired variation. (c) Process of Cross-pollination. — This con- sists in the transference of pollen from a flower of one plant selected to be crossed to the stigma of a flower from the other plant selected. In * Year-hook, i8gg, p. 4S4. Wear-book, 1S98, pp. 355-357- 263 AGRICULTURE. order to do this, it is simply necessary to under- stand the nature and arrangement of the parts of a tlower (Fig. 84). -st FIG. 84. THE PARTS OF A FLOWER. Paris of (I Flo-Mci-. — A typical flower consists of four kinds of organs (calyx, corolla, stamens, and pistil), the parts of which vary in form and number in the flowers of different species. Starting from the outside, the first whorl is the calyx {ex), the separate parts of which are the sepals, usually green. The whorl just within the calyx is the corolla (<), composed of petals, which are often bright colored. Within the corolla are the stamens (j), consisting of filament, or stalk, and anther, or pollen-sac. In the center of the flower is the pistil (/), a stalk-like organ, the upper portion of which is somewhat rough and swollen, and is known as the stigma {st). The stamens and pistil are the only organs concerned in repro- duction, the others being merely accessory. The organs concerned in fertilization are the stamens (male organs) and the pistils (female organs). In many plants both stamens and pis- tils are borne on the same flower — as, the bean and pea ; in others they are borne on the same IMPROVEMENT t)F PLANTS. 2G3 plant but in separate flowers — as, the corn and cucumber ; while in still others they are pro- duced on separate plants — as, the ash and box elder. In case both stamens and pistils are borne on the same flower, the anthers must be removed FIG. 85. (IKAXr.l". BITD AND HLOSSOMS. a — Orange bud. b — Mature orange blos.som. c — An emasculated flower. before the pollen is shed, to prevent self-fertili- zation. To be sure of this, they should be re- moved before the bud is fully opened (Fig. 85, a), and in certain cases — as, wheat, etc. — in even an earlier stage, since pollination takes place before the bud opens. Directions for cross-pollination: {a) The bud should be carefully opened to expose the anthers (Fig. 85, ^), which should be picked off (Fig. 85, c) with a pair of tweezers, or cut off with a pair of tiny scissors. The best results will be obtained by selecting two or three of the strongest flowers of the cluster for emasculation, and removing all others. {b) The flower cluster thus treated should be at once enclosed in a paper bag, the open end of which should have been slightly moistened by quickly dipping it in 264 AGRICULTURE. water. Now the bag sliould be carefully tied around the twig, below the flower cluster, so as to insure the exclusion of insects and undesirable pollen (Fig 86^'). (r) The bag should be removed from time to time and the stigma examined with a hand-lens, to see if it is ready to receive the pollen. This can usually be told Pi^nl^^^^^^^^^^^^^^l ■ .ff'^Q^H ■ kJ HM^ FIG. 86a. ORANGE FLOWER Enclosed in paper bag after emasculation. FIG. 86(5. — NEARLY MATURE HYBRID ORANGE Enclosed in gauze bag to prevent loss by dropping. by the presence of a mucilaginous excretion, or by the appearance of papillae upon the surface of the stigma. {d\ It should not be forgotten that the flowers from the other plant selected to be crossed must likewise be protected from insects and foreign pollen. This is done by enclosing the entire flower cluster in a paper bag be- fore the bud opens. (e) When the anthers begin to open, the pollen should be collected, labeled, and kept until the stigma is ready to be fertilized. Then the pollen is gently applied to the stigma by means of a fine-pointed scalpel or even a pen- knife. IMPROVEMENT OF PLANTS. 265 {/) When the stigma is pollinated, it should be re- sacked and labeled. (g) After the fruit is set, it might be well to replace the paper sack with a gauze one (Fig. 86/^), which should be allowed to remain until the fruit is ripe, thus freely admitting air and light, yet affording protection from insects and birds, and preventing its loss by falling or being picked through mistake. 3. B?(d Variation. — It may be that a single branch may show new and striking characters (Fig. 87), and possibly very desirable ones ; for example, the smooth skin of the nectarine is the product of a bud variation of the peach, and the mossy stem of the moss-rose is also a bud varia- tion or so-called sport.* It becomes necessary to perpetuate such varia- tions by bud propagation, since the characters of the plant as a whole are more likely to be re- produced through the seed, even of that partic- ular branch, than are the characters of a single branch. f III. Fixing the Type. It must be remembered that thus far only a star tijig- point for a variety has been obtained. It yet remains "to fix" that variety — that is, to make it "come true" from seed. This requires far more skill and patience than the work of securing the desired variation in the first place. "Selection is the force which augments, de- * Bailey's Plant Bretding, p. 161. \ Year-book, X898, 357. 266 AGRICULTURE. FIG. 87. COSMOS in.OWKRS. From same stem, showiug variation. velops, and fixes type." * When a seedling possesses desirable qualities, " it is almost in- variably necessary to render these characters hereditary by careful and continued selection and in-and-inbreeding- through several gen- erations." Year-book, 1897, p. 40S. IMPROVEMENT OF PLANTS. 267 While the tendency of the plant to vary is so essential in furnishing the starting-point for a new variety, it is also the most difficuU factor'- to overcome in making that variety approach a fixed type ; for out of a number of seeds from the plant having the desired characters, only one 1st year SELECT PLAKTT^l) 2oYE:AR ioVEAR 4t>»YEAR 5th YEAR SELECT PLANT (T)*K SELECT PLANTt SELECT PLANT(T) -DIAGRAM SHOWING METHOD OK SELECTING AND IMPROVING SEED. may come true. In that case, seeds should be used from that one plant only, and these planted in an isolated place. Possibly the next genera- tion may furnish several of the desired plants, and again seed must be selected only from these. WitJi selection, isolation, and cultivation con- timied for many generations, one may hope to obtain seeds the majority of which will come 268 AGRICULTURE. true. But the work of selecting the best seeds from the most uniform and typical plants must never be neglected, or the plants will in time revert to degenerate types. If inbreeding is not possible, the variety may be perpetuated by bud propagation where prac- ticable ; indeed, in many cases it is the possi- bility of propagating by buds that makes the crossing of plants profitable.* C— REFERENCES. "Progress in Plant and Animal Breeding." Year-book, 1901. United States Department of Agriculture. " Progress of Plant Breeding in the United States." Year- book, 1899. " Hybrids and Their Utilization in Plant Breeding," Year- book, 1S97. " Influence of Environment in the Origination of Plant Varie- ties." Year-book, 1896. "Improvement of Corn by Seed Selection." Year-book, 1902. "Pollination of Pomaceous Fruits." Year-book, 1898. " Improvement of Plants by Selection." Year-book, 1898. "The Improvement of Our Native Fruits." Year-book, 1896. " Every Farm an Experiment Station." Year-book, 1897. "Improvement of Corn by Seed Selection." Missouri Agri- cultural Experiment Station. "The A. B.C. of Corn Culture." P. G. Holden. 11. " Plant Breeding." Bailey, 1897. 10. "Principles of Plant Culture." Goff, 1S99. Published by author. "Self-Origination of Species and Cross-Fertilization." Dar- win. 9. "Variations of Animals and Plants Under Domestication." Darwin. 9. " Origin of Cultivated Plants." De Candolle. i. * Bailey's Plant-Breeding, p. 51. OUTLINE OF CHAPTER XL PRUNING OF PLANTS. General Principles. 1. Development of the Organism. 2. Purpose of the Plant to Itself. 3. Mutual Relation Between Root and Top, A.— HOW TO PRUNE. I, Nature of the Wound. 1. Function of the Cambium. 2. Effect of Improper Pruning. IL Removal of Large Limbs. in. Treatment of Wounds. 1. Pine Tar. 2. Grafting-ivax. 3. Lead Paint. IV. Pruning Back of Small Limbs. 1. Removal of Buds. 2. Removal of New Groivth. ^.— WHEN TO PRUNE. I. Fall Pruning. 1. Advantages : (i) Conserves Food. (2) Prevents Disease. 2. Disadvantage : Not Conducive to Healing. 269 270 AGRICULTURE. II. Spring Pruning. 1. Advantage : Conducive to Healing. 2. Disadvantage : Waste of Food. III. Summer Pruning. (See A.— IV., i.) C— WHY TO PRUNE. I. Pruning at Transplanting. 1 . Trees for Fruit. 2. Trees for Timber. 3. Trees for Shade. II. Pruning to Induce Fruitfulness. III. Pruning to Prevent Overbearing. IV. Pruning Hardy Shrubs. Z>.— REFERENCES CHAPTER XL PRUNING OF PLANTS. I. General Principles. Sound reasoning- is the first requisite to suc- cess in pruning. 1. It should be borne in mind that the first work of importance in growing a plant is the devclopine7it of a strong, wcll-foruicd oroanism. This development depends upon selection, pruning, food supply, and other environmental conditions. 2. The basic principle of all subsequent prun- ing is the fact that the paramount pui'posc oj the plant (to itself) is that of perpetuating the species, and that it does this both asexually and sexually. Asexual reproduction is accomplished by the formation of buds, which develop into branches. These may or may not become separate plants. Sexual reproduction is accomplished by the formation of buds, which develop into flowers and fruit, the seed of which give rise to separate plants. One of these methods of reproduction is apt to predominate, and hence the food supply will be taken for its support at the ex- pense of the other method. 271 273 AGRICULTURE. Pruning is an important factor in regulating and, in a measure, controlling these two adverse tendencies of the plant to suit man's purposes. 3. Another point which must not be over- looked is the imttjial relation between root and top. In the normally developed plant there is a state of equilibrium between the leaf-system and the root-system. As the top develops there must be a corresponding development of roots to supply the crude material to be converted into food by the leaves, and in turn there must be a corresponding growth of the leaf-system — if the root-system is to be enlarged — in order to convert the crude material into food for the growth of new roots. Hence, when this equi- librium is disturbed, either accidentally or on purpose, the plant bends its energies to restore it. Thus it is that pruning the roots checks the growth of top, and pruning the top not only checks the growth of roots, but gives increased food supply to the remaining parts. A.—WOVJ TO PRUNE. I. Nature of the Wound. It will be seen from a careful study of a cross- section of a stem (Fig. 89), that in order for the cut surface to heal it must be in direct commu- nication with the cambium layer of the stcpport- ing stem. I. Function of the Cambium. — The process PRUNING OF PLANTS. 273 FIG. 89. — DIAGRAMMATIC CROSS-SECTION OK A BASSWOOD STEM TWO YEARS OLD. / — Pith, m — Medullary raj's. c — Cambium, vb — Vascular buudle. of healing Is carried on by the throwing out of new tissue at the cut edge of the cambium, which gradually rolls out from the circumference to- ward the center of the wound (Fig. 90), where in time it unites and forms a continuous layer of cambium, which gives rise to both wood and bark cells, as in any other portion of the stem. // is of the 2ttmost ivi- portance that in remov- ing the limb the cut should be made in such a manner as to bring all parts of its circumfer- ITG. 90. — IMPROPER AND PROPER PRUNING. a — Cannot heal, b — Healing. 274 AGRICULTURE. ence as near as possible to the supporting stem. This is done by making the cut surface parallel to it (Fig. 90) ; for in this case the cut edge of the cambium still receives its food supply from the supporting stem. 2. Effect of Improper Pruning. — But if the limb is cut off so as to leave a projecting stub, healing cannot take place, since the prepared food for the support of this branch was elab- orated by its leaves and sent toward the triink; the supply having been removed, the cambium layer of this stub cannot grow. As a result, not only will the healing be prevented, but the cam- bium and bark will die back, leaving an unsightly stub of wood to rot down to the supporting limb or trunk ; and when the stub drops out, dust, water, and fungi, or other vegetation, will collect in the cavity left (Fig. 91), and thus in- troduce disease and decay into the heart of the tree, weakening its structure and possibly de- stroying it. II. Removal of Large Limbs. Should it become necessary to remove a large limb, it would be advisable to saw it off about a foot from the trunk of the tree, so there would be less danger of splitting down the trunk by the weight of the limb. This danger would be further lessened by making two cuts — the first below the limb to about the center, the second cut above the limb and just beyond the first cut, Z K *. £ ^ :;; 3 C O O z ? 5 ^ > /5 CS X o »4 t^ "ni is z rt S S w p 276 AGRICULTURE. as in Fig. 93. The remaining stub should now be sawed off close to the trunk (see Fig. 90, b). III. Treatment of Wounds. Where the cut surface is large, some protective substance should be applied to the exposed tissue. Tar is sometimes dressing for these It is regarded as an excellent one. 2. Another dressing which may be used upon any tree without injury is Grafting-wax (see Chapter IX., p. 237). 3. Lead Paint \'s> Ao\i\:)X\.^^?> the best dressing for all kinds of trees, since it is not only durable, but to some extent antiseptic, and comparatively inexpensive. IV. Pruning Back of Small Limbs. I. Removal of Buds.— The ideal method of pruning, or that which would insure to the plant the least waste of energy, is the pinching or rubbing off of buds that would develop into branches which would need to be pruned off. This method of pruning is especially adapted to the early or formative period of a plant's de- velopment. If close attention be given to the FIG. 93. THE WAY TO REMOVE A LARGE LIMB. PRUNINC. OF PLANTS. i removal of buds the plant may Ix- made to con- form to any dcsircMl shape. l^y the removal of the terminal bud the plant may be made to put out lateral branches, and thus become short and bushy {V\g. a 83), or by removing the lateral i(^ branches it will throw the more vii»"or into the central stem, causing- it to become long and slender. 2. Removal of New Growth. — In large trees the; above; nu;thod is impracticable. The best practical method for such trees is to in- spect them each year and remove such branches, or portions of branches, as growth may indicate;. In doing this pruning the branch should be cut off just above a bud (as in Mg. 94), taking care not to cut too close to the bud, as it would then dry out. \ km;. 94. — WllKKK TO CUT TWV. NKW GROWTH. ^.— WHKN TO PRUNE. If tlie purpose of pruning is merely to remove dead or deceased branches, or the pinching off of superflous or undesirable buds, the work may be done at any time when it is necessary. It is agreed by the best authorities that gen- eral pruning should be done while the trees are in a dormant state. There is, however, a dif- 278 AGRICULTURE. ference of opinion among" these authorities as to whether this work should be done as soon as the leaves are shed in the fall or before the buds have begun to swell in the spring. I. Fall Pruning. 1. TJic advantages of fall pruning are : (i) that a greater amount of food would then be distributed over a less number of branches ; for by spring, owing to the slow dissemination of food taking place through the winter months, the nutriment would already have been distrib- uted to all the branches of the tree, particularly to their terminal portions, which would be re- moved by spring pruning i"^'' (2) that immature branches, which would probably be frozen and tend to injure the tree, would thus be removed. 2. However, there is one decided disadvan- tage in fall pruning ; that is, that the wound does not readily heal. This is due to the fact that healing is affected by the growth of the cambium layer, and as this is inactive in winter, healing cannot take place at that time. Hence, the exposed surface is liable to dry out or freeze, thereby inducing decay of the wood and invit- ing disease. II. Spring Pruning. I. The main advantage of spring pruning lies in the fact that the wound readily heals, owing to the active condition of the cambium layer. * Authorities are not agreed upon this point. PRUNING OF PLANTS. 379 2. The chief disadvantage is the waste of energy of the plant in the loss of the accumu- lated food supply by the removal of the terminal portions of the branches. Exercise ii. — To study tlie effect of fall and spring pruning, let the student remove several small branches of as man}' different kinds of trees as are accessible, carefull}' labeling each branch pruned with the student's name and the date of pruning. In the spring let them prune off as many more branches from the same trees and label with date. Just before school closes for the year critically exam- ine all the branches pruned. Compare and tabulate results. Was the result in each case due to the lime of pruning or to the position and nature of the cut ? C— WHY TO PRUNE. One should never remove a limb or even a twig from a tree without knowing why. I. Pruning at Transplanting. The utmost care should be taken in lifting plants for transplanting, but even then many of the fine feeding roots will be broken off or mutilated ; consequently, the equilibrium be- tween root and leaf will have been destroyed. To re-establish the equilibrium : first, all the mutilated roots should be cut off, so that the energy of the plant may not be wasted in trying to restore these injured parts; second, the leaf- bearing surface should be reduced to correspond to the loss of root-system. This principle holds good in the transplanting of any plant. 280 AGRICULTURE. The vianncr in which phmts are pruned at transphmting depends largely upon the purpose FIG. 95. — APPLE-TREE HEADED LOW. for which the tree is grown. If grown ior fruit the tree should be headed low (Fig. 95); that is, the first limbs branching^ out from the trunk PRUNING OF PLANTS. 281 U. S. Dei.t. A-r. FIG. 96. — TREES GROWN CLOSE TOGETHER FOR TIMBER. should not be more than eighteen inches from the ground. At the same time the lateral branches should be pruned back so that the cen- tral stem will lead. The advantages of heading a tree low are: (i) it makes a tree stronger and less liable to be 282 AGRICULTURE. blown over; (2) the trunk is thus protected from the direct rays of the sun, thereby prevent- ing sun-scald ; (3) that the tree's energy is con- served by lessening the distance through which the food is carried ; (4) that the fruit is easier gathered. The greatest objection in heading a tree low is that it renders cultivation more difficult. 2. If a tree is grown for timber,^ tall, straight trunk should be encouraged by pruning off most of the lateral branches and planting the trees close together (Fig. 96), so that they will be forced to grow upright to obtain the light. As the trees develop, and room and food supply become insufficient, some of them should be re- moved. 3. Slow-growing shade-trees require very little or no pruning, save the removal of diseased or broken branches. But rapid-growing shade- trees — as, some of the maples — should have a portion of the last season's growth pruned back each year, thus forming a compact head, making the tree stronger, and obviating the necessity of severe top-pruning, which renders the tree use- less (for shade, at least) for one year, as well as presenting a very unsightly appearance. II. Pruning to Induce Fruitfulness. As has been said, the paramount natural pur- pose of a plant is that of reproduction. Every plant has a certain amount of available food. In PRUNING OF PLANTS. KIG. 97. — NORWAY M.^I'LE (Acer platanoides^ . Horticultural Grounds, Missouri Experiment Station. the early years of its development this food supply should be directed to the upbuilding of a strong, vigorous tree; but when the tree is mature, if one system of reproduction predominates over the other, it uses more than its share of this available food and the other system is deprived of its rightful portion, and thus its development is checked. Man may, by pruning or other means, equal- ize the distribution of food. If vegetative 284 AGRICULTURE. growth or asexual reproduction is so far in the ascendency as to prevent the development of fruit, this growth should be checked. Slight "heading-in induces fruitfulness by checking growth and by encouraging the formation of side spurs upon which fruit may be borne." " In extreme cases, where a tree has never fruited, the growth may be checked by reducing the food supply. This may be done by with- holding fertilizers, or stopping cultivation and seeding down in grass or clover for a few years, or by judicious root pruning. Root Priming. — Root pruning is attended by considerable risk, as the equilibrum between root-system and leaf-system is thus destroyed. There is less danger of injury to the tree when the work is done in spring, as evaporation is less, and the conditions at this season of the year are more favorable for the readjustment of the growth. Roots are sometimes pruned in summer, when the wood and fruit buds are developing for the next year; thus the formation of fruit buds would be encouraged. But at this period of the year the process is attended by a greater risk, as evapo- ration is very great. The work is done by making a circular ditch around the tree at a distance from the trunk corresponding to the tips of the branches. One * Bailey's Principles ef Agriculture, p. i66. PRUNING OF PLANTS. 285 should be extremely cautious as to the extent of the root surface removed, since the small, grow- ing roots are the feeding roots upon which the plant is dependent for nourishment. III. Pruning to Prevent Overbearing. If sexual reproduction or the development of fruit predominates to such an extent as to be detrimental to vegetative growth, it should be checked by the removal of fruit buds, or a por- tion of the fruit, or even of some of the fruit- bearing branches. At the same time the vegetative growth should be encouraged by increasing the food supply through renewed cultivation and the application of nitrogenous fertilizers. IV. Pruning Hardy Shrubs. If the shrubs are grown for a hedee — as. the barberry {Berberis vulgaris), burning-bush (^Pyrus Japonica), or osage orange — the new growth should be sheared each year, forming a compact head. I. Early Flowering Shrubs, such as lilac, syringa, weigelia, and many roses, which pro- duce blossoms from buds developed the previous summer, should be pruned after they have bloomed. The terminal bud should be pinched out of the new growth to induce lateral branches, which will develop blossom buds for the next year. Pruning these shrubs in early spring would remove the blossom-bearinor wood. 286 AGRICULTURE. 2. Sliritbs which produce their blossoms from buds produced the same stuuincr, such as the althea, hydrangea, and button bush, should be pruned in early spring to increase the blossom- bearing wood. To admit more freely the air and light, the old branches — and, if too thick, some of the entire flowering stems — should be cut out. This will tend to increase the size of the blossoms, which may be further enlarged by pinching out some of the flower buds. (See "Plant Improvement.") Exercise 12. — kw expedition should be made to an orchard or grove, for the purpose of observing the actual conditions of all phases of the work suggested in this chapter. A written report should be required, touching upon all the points of the outline, which are exemplified by any plants seen during the trip, (a) Note upon a mature plant the effect, upon its use and upon its strength, produced by correct, incorrect, or no pruning in its eaiiy stages of development. (b) If in fruiting season, do you note any trees which are overbearing? Any that are not bearing ? Can you see why ? How would you effect a change ? {c) Note wounds that are healing. Describe and ex- plain. Do you note any that have not healed ? Why? Could this condition have been prevented ? Explain. How will it affect the tree? What treatment would you advise ? 2;.— REFERENCES. " Pruning and Training of Grapes." Yearbook, iS(j6. United States Department of Agriculture. " Principles of Pruning and Care of Wounds in Woody Plants." Year-book, 1895. " Pruning of Trees and Other Plants." Year-book, 1898. " The Pruning Book." Bailey. 1899. 10. " The American Fruit Culturist." Thomas. 1S97. OUTLINE OF CHAPTER XII. ENEMIES OF PLANTS. .4.— INJURIOUS INSECTS. I. General Characters of Insects. II. Metamorphosis. III. Apparatus Needed in Collecting and Rearing Insects. 1. Net. 2. Cyanide /'Ottle. 3. Byecdiiig-jars. IV. Field Trip. V. Laboratory Studies. 1 . Study of the Live Insect. 2. Grasshopper. 3. Nymph. 4. Butterfly., or M-th. 5. Caterpillar. VI. Economic Classification of Insects. 1. Group I.— With Bitini^ Mouth-parts. 2. Group II. — With Sucking Mouth-parts. VII. Preventives. 1. Removal of Debris. 2. Change of Crops. VIII. Insecticides. 1. Group I. — Poisonous Insecticides. 2. Group II. — Contact Insecticides. 287 288 AGRICULTURE. IX. Study on Spraying. X. Natural Enemies. 1. The Birds. 2. Predaceous Insects. (i) Specific Examples. (2) Required Exercise. XI. Specific Examples of Injurious Insects. 1. Flant-lice. 2. Rose-slug. 3. Tent-caterpillar. 4. Forest Tent- caterpillar. 5. Codling- moth. 6. The Borers. (i) Example: The Round-hkaded Apple-tree Borer. (2) Preventives. i5.— INJURIOUS FUNGI. I. Specific Examples. 1. Brown Rot. 2. Black Rot. 3. Bitter Rot. 4. Apple Scab. . II. Fungicides. 1. Bordeaux Mixture. Dust Bordeaux. 2. Ammoniacal Copper Carbonate. C— REFERENCES. CHAPTER XII. ENEMIES or PLANTS. In dealing with plants one of the most im- portant problems which arises is how to meet their enemies. In order to do this one must know something of the nature and habits of each particular species which he needs to con- trol. Actual observation of them at work is the best means of obtaining a knowledge of the enemies of plants. But some good work on in- sects and fungi (like those listed at the end of the chapter) should be consulted, or if none of these are at hand, one should write to one's own State Entomoloofist for advice and literature. These enemies may be divided into two great classes: (i) animal forms, (2) plant forms. Among animal forms the most important ene- mies of plants are injzcrious insects. y^.— INJURIOUS INSECTS. I. The General Characters of Insects in the adult state are one pair of antennae; three body divisions, head, thorax, and abdomen ; three pairs of legs, and two pairs of wings. 2S9 390 AGRICULTURE. II. Metamorphosis, or Development, of Insects. All insects develop from eggs, and all undergo a more or less marked change in form during their life-cycle.* Many insects when they emerge irom the Ggg are much like the adult form. These nymphs, as they are called, have no wings. They feed greedily, and as growth demands the hardened skins split and are cast — that is, the insects molt. The wings, if wings are present in the adult stage, develop as little pads, which grow larger with each molt until the adult stage is reached, when growth ceases. This method of develop- ment is called incomplete metaniorphosis, the three stages of which are ^gg, nymph, and adult. Common examples of this method of develop- ment are grasshoppers, crickets, plant-lice, and dragon-flies. Many other insects, when they leave the ^^g, differ markedly in form from that of the adult. These caterpillars, grubs, maggots, etc., as the case may be, are called the larva;. In this larval or second stage they feed, grow, and molt, but do not change their form. When they are full grown they stop eating, become restless, and pass into the third stage of their development (that of the pupa), some attaching themselves to a stick or leaf, others spinning a cocoon, while * Those insects belonging to the small order T/iysaiiirra un- dergo no metamorphosis. ENEMIES OF PLANTS. 591 still others form a leathery case and bury them- selves in the ground. Here they remain quiet for a time, when the pupa-cases split open and the adult forms emerge, lay their eggs, and thus FIG. gS.^NET FOR COLLECTING INSECTS. their life-cycle is completed, and the life-cycle of another generation is begun. III. Apparatus Needed in Collecting and Rear- ing Insects. A few simple, inexpensive articles are all that is necessary. Nets, cyanide bottles (Fig. 99), and a few empty bottles will be needed in collecting. I. The net may be made by bending a heavy wire into a circle about a foot in diameter, turn- ing the ends of the wire out, as shown in Fig. 98. For a handle an old broomstick may be used. A hole should be made in the end by burning it with a hot iron rod or boring it with a small bit. Now fasten the ends of the wire firmly into this hole with pegs or nails. Make a cheese-cloth sack a yard long, round one cor- 292 AGRICULTURE. ner off, and firmly sew the open end to the wire, as in Fig-. 98. 2. Cyanide Bottle for Killino- Insects. — Place in a wide-mouthed bottle, which will hold about a pint, a few small pieces of potassium cyanide. This should be handled with great care, as it is Potass ivfn FIG. 99. — CYANIDE BOTTLE. FIG. 100. — BREEDING-JAR FOR REARING INSECTS. extremely poisonous. Now cover the cyanide with a layer of plaster of Paris. Thoroughly moisten the plaster of Paris with water, pouring it in slowly through a funnel to prevent the sides of the bottle from being smeared. Let it stand until the plaster of Paris sets. Remove any surplus water, and allow the bottle to be- come thoroughly dry before using. Tightly ENEMIES OF PLANTS. 293 close the bottle with a cork thick enough to be easily removed (Fig. 99). 3. Breeding-jars for rearing insects should be prepared before the insects are collected. Place about two inches of clean sand in the bottom of glass fruit-jars ; moisten the sand, and provide covers of cheese-cloth, or mosquito-netting, and narrow rubber bands to keep them in place. IV. Field Trip. Equipped with net, cyanide bottle, and empty bottles for the reception of live insects, the class should make afield trip to study the habitat and the habits of insects, and to collect their own material for laboratory work. (^j") Look in the grass and weeds, under leaves, stones and boards, and on the bark of trees. Are some insects harder to find than others ? Why ? Why do you find certain kinds in one place rather than in another? Ob- serve especially upon what plants and what part of the plant each species is found feeding. Collect a portion of this plant to place in the breeding-jar with this insect when you get home. Notice how the plant has been affected by the feeding of the insect. Are there any holes in the leaves or stem ? How were they made ? In what stage of the development of the insect was the damage done ? (See " Water Forms," a and b?) V. Laboratory Studies. I. Study of the Live Insect. — Keep each species of in- sect in the breeding-jars supplied with fresh food, and watch each through all the subsequent changes of devel- opment. {a) Make careful notes and drawings on each stage. {b) Does the insect eat the tissue or simply suck the juices of its plant-food ? Hoin does it obtain its food in each stage of development ? 294 AGRICULTURE. (t") Will any of tlie insects in the larval or adult form eat other insects in any stage cf development ? Water Forms. — If the students have access to a pond or stream, it would be both interesting and instructive FIG. lOI. — COLLECTING INSECTS. to (a) collect forms which pass through some or all the stages of development in the water. [d) Take a quantity of the mud and water in which these \\ater forms are found, together with algae, or other food, back to the laboratory, and place with the different species in breeding-jars similar to that in Fig. lOO, {c) Observe all changes in their development, and make careful notes and drawings of eech stage. (d) If there are a number of any one kind, it would ENEMIES OF PLANTS. 295 be well to preserve some of them in a solution of forma- lin (made by mixing one part of formaldehyde, 40 per cent., with 19 parts of water) for museum specimens. If possible, have each stage of every species represented in your collection of specimens. 2. The Grasshopper. — Find the three body divisions — head, thorax, and abdomen. The Head. — (1) Find the antennce (slender feelers). How many segments in each ? Draw. (2) Find the compoutid eyes. Examine a portion of one under the low power of the microscope. What is the general shape of these parts, or facets, of the eye ? Draw several of them. In what direction can the grasshopper see ? (3) How many ocelli, or simple eyes, do you find ? (4) Mouth-parts. — {a) Find the labrum, or upper lip. Lift and remove it. Draw. {I)) Note the mandibles, or true jaws, exposed by the removal of tlie labrum. In what direction can you move them ? Take out one. Draw. Does the grasshopper obtain its food by biting or sucking ? (c) Find the labium, or lower lip. Remove it. Draw. Is it a single appendage or two united ? {il) Look for the labial palpi attached to the labium. How many segments in t.^ch. palpus ? {e) Find the maxillcc, just in front of the labium. These each consist of three parts united at the base ; the outer one, tlie maxillary palpus j tlie middle one, a spoon- shaped piece, the galea ; the inner piece, the lacinia, [maxilla proper). Draw. (5) Take a fresh specimen and draw a front view of the head, labeling all the parts.* * Every question in the above outline should be answered by actual observations upon the insects. It may be that the student will be better able to answer some of these questions, after hav- ing made the laboratory study of the live insect. 296 AGRICULTURE. The Thorax. — The segments of the thorax are the prothorax, mesotliorax, and vtetathorax. (i) What append- ages has each? Look on the mesothorax, just above the legs, for a pair of spiracles or breatliing pores. Do you find another pair between mesothorax and meta- thorax ? (2) Draw the thorax, and label the parts. The Legs. — (i) How do the first and second pair of legs differ from the third pair in size, and in the direc- tion in which they extend from the body? Why? What modes of locomotion lias the grasshopper? (2) Make a careful study of the hind legs, {a) Note the coxa, a short segment attached to the body. Next to it is the trochanter, another short segment. The femur is the large segment following this, attached to which is the slender tibia. With what is tlie latter armed ? For what purpose ? The terminal portion is the tarsus or foot. Is it segmented ? Note the hooks and pads. {p) Make a drawing of the entire leg, and label each part. The Wings. — {a) Note the wings on one side of the body while folded, and their position with reference to the body; with reference to each other. {b) Spread tliem out and compare as to size, shape, color, use, texture, and position. {c) Make a carefid drawing. The Abdomen. — (i) How many abdominal segments do you find ? Are the last three distinct ? ^2) {a) Look alon^ the groove on each side of the abdomen for spiracles. How many in each of these segments ? In how many segments are they found ? {p) Catch a live grasshopper and watch it breathe. Do the walls of the abdomen move ? What movements have the spiracles ? Try to drown the grasshopper by holding its head under water. Explain. (3) Find the ear membrane on the side of the first segment. ENEMIES OF PLANTS. 297 {4) (a) Examine tlie end of tlie abdomen. Is it blunt, and do you find two appendages, the cerci, on the upper side ? If so, the specimen is a male. If the end of the abdomen is tapering and divided into four points — parts of the ovipositor — the specimen is a female. {l>) Draw the abdomen, showing all the parts. Draw the entire grasshopper as seen from the side. Now, before discarding the specimen, cut through the mouth beyond the oesophagus into the crop, open it, and examine its contents. See if you can find out what is the grasshopper's food. 3. T/ie A^xiiiph, or Young Grass/topper. — Do vou find all the parts mentioned in the study of the adult grass- hopper present in your specimen ? {a) Compare the parts with those of the adult. {/>) Draw a side view of the nymph. 4. T/ie Butterfly, or Moth. — Identify tiie three body divisions, and locate the antennae, eyes, legs, wings, and spiracles. Compare with those of the grasshopper. Mouth-parts. — Make a careful study of the mouth- parts, (i) Note .the two short projections, the labial palpi, in the front of the head. (2) Uncoil the long tube between the palpi and ex- amine it. The parts of the tube correspond to the maxillse of the grasshopper. (3) ('0 Does the butterfly obtain its food by sucking or biting? Are there other mouth-parts present? [b) Make a drawing of the mouth-parts present in their natural position. (r) Remove them, and draw. 5. Caterpillar. — Make a careful examination of some caterpillar, the larva of a moth or butterfly — for ex- ample, the tomato-worm. (i) Do you find the general characters of the adult insect — three body divisions, one pair of antennae, and three pairs of legs — in the caterpillar? 298 AGRICULTURE. (2) Do you find eyes, spiracles, and mouth-parts? How do they compare with those of the adult moth ? (See mouth-parts of the butterfly.) (3) Make drawings of the entire larva, showing all parts. (4) Remove the mouth-parts, and draw. Are they adapted tor biting or sucking? VI. Economic Classification of Insects. Insects are divided into two great groups ac- cording to their mouth-parts, in order that one may know what insecticides to apply in com- bating them Group I. — This includes all insects in that stage of their development in which their mouth parts are formed for biting. These insects actually bite off, chew, and swallow small por- tions of the plant or other material upon which they feed. Consequently, they would be killed by poison placed upon the food and taken into the stomach. Common examples of this group are grasshoppers, beetles, and caterpillars. Group II. — This includes all insects in that stage of their development in which their mouth- parts are formed for sucking. These insects obtain their food by thrusting the beak below the surface of the plant or animal upon which they feed and sucking its juices, but they do not swallow any of its tissue; hence, poison placed upon the surface of the plant-food would not be taken into the stomach by the insects of this ENEMIES OF PLANTS. 399 group. Plant-lice, scale insects, mosquitoes, tiies, etc., are examples of Group II. The student should have already observed that an insect, according to the form of its mouth-parts, may in one stage of its develop- ment belong to one of these groups, while in another stage it belongs to the other — as, the tomato-worm, the larval stage of the sphinx- moth, which belongs to Group I., while the adult stage, the moth, belongs to Group II. VII. Preventives. A siuall amount of time and labor spent in preventing insects from becoming established on the farm is often of more value than a great amount spent in trying to destroy them. 1. Removal of Debris. — By the prompt re- moval and burning of all dying or diseased branches, trees, or plants, decayed fruits, and general debris, many insects, as well as their eggs, will be destroyed; while if such mate- rial is allowed to remain, it will afford protection for insects duringr their hibernatinof and breed- ing seasons, thus promoting the development of overwhelming^ numbers. 2. Change of Crops. — If an insect pest makes its appearance in a field of grain, one may pre- vent its devastation the following year by plant- ing the field in some other crop upon which the insect does not feed. For example, the Hes- sian fly may be observed in a field of wheat. 300 AGRICULTURE. The following- year the development of the Hessian tly in this field may be prevented by putting in a crop upon which it does not feed — as, corn or clover. VIII. Insecticides. In general, insecticides also are divided into two groups. Groiip I. — Poisonous Insecticides, or those that kill by being taken into the stomach of the insect. The principal poison in this group of insecticides is arsenic in some form. Paris o-reen is the most common, and if una- dulterated is a very effective arsenical insecti- cide. It is prepared as follows: Paris green i pound Quicklime i pound Water 100-300 gallons Mix thoroughly, and strain the mixture through a gunny-sack or sieve. The purpose of the lime is to render any free arsenic in the Paris green insoluble, since soluble arsenic would poison the tissue of the plant. It must be remembered that the particles of arsenic are held in suspension and not in solution ; hence, the mixture must be kept well stirred while being- applied. In spraying plants with tender foliage — as, the peach and plum — the Paris green mixture should be diluted. Scheele's green differs from Paris green in ENEMIES OF PLANTS. 301 that it does not contain acetic acid, and in the per cent, of arsenic. It has the advantages of being held longer in suspension, as it is a finer powder, and of costing only about half as much. Home preparation insures purer and better arsenical spraying mixtures — as, arsenite of soda and arsenate of lead. White arsenic i pound Sal soda 4-5 pounds Water 2 gallons Mix the above ingredients and boil until clear — about fifteen minutes. Add enough water to replace that which boiled away. This forms a stock solution which should be placed in Mason jars, labeled poison, and kept until needed. This stock solution is used similarly to Paris green. Since it is soluble in water, and hence would damage the foliage, it is prepared for use by mixing two quarts of the stock solution and eight or ten pounds of freshly slaked lime with one hundred gallons of water. Arsenate of Lead.^ — This insecticide has several advantages over the others just men- tioned: (i) it can be used in stronger solutions and in larger quantities without injuring tender foliage, since it is absolutely insoluble in water ; (2) it will remain longer in suspension ; (3) * Commercial arsenate of lead sold under the name of dis- parene, is said to be perfectly reliable. It comes in paste form, and sticks on the foliage well. 302 AGRICULTURE. being white, it can be more readily seen on the foliage, thus indicating what has and what has not been sprayed. It is made as follows : Arsenate of soda 4 ounces Acetate of lead ii ounces Water 25-100 gallons Glucose 2 quarts Dissolve the acetate of lead in a zvooden bucket of warm water, and the arsenate of soda in another bucket of warm water. When thor- oughly dissolved, pour both into the quantity of water to be used, according to the strength of the poison desired, at the same time stirring rapidly. If two quarts of glucose be added, the spray will not be so easily washed off by rains. In applying any of the arsenical mixtures, the spraying should not be continued until the water drips from the foliage, as the fine particles of poison are carried away in the drops instead of being left upon the leaf by evaporation after a less quantity is used.* Group II. — Contact Insecticides, or those that kill by contact with the body of the insect. These may be effective in two ways, either by *Di'ST Strays. — White Hellebore the root of a plant, kills both by contact and by poisoning. It may be applied dry or in the liquid form. If used dry, it may be easily applied by mixing it with three or four times its weight of flour and dusting it over the plants when they are moist with dew, from a little cheese-cloth sack or applied with a hand dust-spray or bellows. Paris Green may be used dry by mixing it with ten times its weight of flour, and may be applied in the same way as the Hellebore. ENEMIES OF PLANTS. 303 penetrating the breathing pores and suffocating the insect or by corroding the body. (i) Kerosene Emulsion. — Of the contact in- secticides, kerosene emulsion is one almost universally used by Agricultural Experiment Stations. The emulsion formula : Soap 1^ pound Soft water i gallon Kerosene 2 gallons The best soap for this purpose is whale-oil soap, though ordinary soft soap or hard soap will answer. The soap should be shaved into the water and thoroughly dissolved by heating. When boiling hot, pour the solution into the kerosene, aioay from the fire, and churn vigor- ously about ten minutes by pumping the liquid back and forth with a force-pump until it resem- bles buttermilk. The emulsifying will increase the bulk about one-third; hence, the emulsion should not be prepared in too small a vessel. If tightly sealed, this stock solution will keep for some time. When wanted, dilute with ten to twenty parts of water. If too strong, the kerosene will injure tender foliage. Apply with a spray-pump (Fig. 102) to the infested plants. The emulsion must come in contact with the body of the insect, so that the kerosene may penetrate the breathing pores and suffocate the 304 AGRICULTURE. insect. The soap also tends to clog the breath- ing pores. (2) Tobacco in various forms is a useful in- secticide. Its use is especially recommended for house plants, greenhouses, gardens, and orchards. As a spray, it is prepared by steeping the stems of refuse tobacco, and usinof the tea in a di- luted form. Nikoteen as commercially pre- pared is excellent for house plants and roses if applied in a dilute form. Tobacco dust or stems is an excellent preventive or remedy when scattered about the Hoor under benches in greenhouses. It is doubly useful when scattered about on the surface of the soil around plants, since it is rich in potash, and acts as a fertilizer as well as an insecticide. Tobacco Smudge. — This is an especially good remedy in the greenhouse, or in places where the smoke can be confined. The smudge is made by slow/y burning moistened tobacco, taking care that it does not burst into flame. FIG. 102. — A BUCKET SPRAY. ENEMIES OF PLANTS. 305 Care should be taken not to allow the plants to be too long exposed to the strong fumes, or the foliage will be damaged ; hence, it will be necessary to repeat the smoking.* Carbon bisulphide is especially adapted for use in store- houses, seed- boxes, mu- seum - cases, etc., or as a remedy for underground insects, such as borers and root-lice. It is a color- less, mobile, and a very volatileliquid. It is not only very infiarnmable, hut ex- treme/y poisonous ; therefore, great caution should be taken in using this insecticide. Under no condition should a lighted lamp, or a FIG. 103 (a). — THE BORDEAUX NOZZLE. FIG. 103 (/')• — HAND STRAY — CUNVENIENT SPRAY FOR LOW PLANTS. * There is nothing better for fumigating than " Nikoteen Aphis Punk." 306 AGRICULTURE. cigar, or even a spark of fire, be brought near the fumes. For storehouses, bins, etc., place the liquid in small, shallow dishes. These should be placed near the top of the bin, since the fumes of car- bon bisulphide are heavier than air. This bin should be kept tightly closed for twenty-four to forty-eight hours, and then zvell ventilated. The amount of the liquid used should be in the proportion of one pint to one thousand cubic feet of space. For destroying root pests, small vertical holes should be made in the soil around the plant. Into each hole pour a teaspoonful of the carbon bisulphide and cover at once. Car- bon bisulphide is also useful in protecting furs and clothing, since it volatilizes and leaves no stain. The odor is so disagreeable and pene- trating that the clothing must be well aired for several days before wearing. Of the contact insecticides that kill by cor- roding the body of the insect, those most com- monly used are lime, soap, and carbolic acid. These are effective on soft-bodied insects, lime being, perhaps, the most important. Lime is useful both as a preventive and a remedy. It may be applied dry as a dust or as a whitewash. Some of the contact insecticides — as, kerosene emulsion and carbon bisulphide — are equally ef- fective upon biting and sucking insects, since they kill by suffocation. ENEMIES OF PLANTS. 307 IX. study on Spraying. Exercise 13 — (a) From the formulas given, compute the amount of each material required to make one-half gallon of some one arsenical spray — as, Paris green — and one of the contact insecticides — as, kerosene emulsion — and carefully prepare each. {U) Spray some plants infested with caterpillars or slugs — as, the tomato-worm or tlie rose-slug, and other plants infested with plant-lice — with each of these insec- ticides prepared, and watch results. (c) To be absolutely sure of these results, place a por- tion of the plants infested by each of these insects ex- perimented upon in each of two breeding-jars, placing that portion sprayed with Paris green in- one jar and that sprayed with kerosene emulsion in the other. Label each, and note the effect of each spray upon each kind of insect. (^/) Did the Paris green affect all of them in the same way? Examine the mouth-parts of each insect experi- mented upon and explain the action of the poison. {e) Did the kerosene affect all alike ? Explain. X. Natural Enemies. Among the natural enemies of insects are birds, predaceous \ insects, toads, spiders, etc. Few persons realize the extent of the work done by these natural enemies in exterminating noxious insects. Particularly is this true of the birds and predaceous insects. I. The Bi7^ds to which we so begrudge our fruit and grain are more than compensating us for this loss by keeping in check insects that would otherwise increase with such rapidity as to endanger the entire crop of orchard or field. 308 AGRICULTURE. Of the birds of the open field the farmer has no better friend than the meadow-lark. It is unrivaled as a destroyer of injurious insects. The stomachs of two hundred and thirty- eight meadow-larks, collected from twenty-four different States, and in every month of the year, FIG. 104. — MEADOW-LAKK {.Salurnella magna). (United States Department of Agriculture.) examined by the United States Division of En- tomology, showed that 72 per cent, of the food of these larks was insects, while only 27 per cent, was vegetable matter. The unassuming little house-wren is one of the most useful birds in destroying insect pests. Actual examination of the contents of the stomachs of wrens by the Division of Entomol- ENEMIES OF PLANTS. 309 ogy at Washington shows that 98 per cent, of the food of the wren consists of injurious in- sects. Many other birds of wide geographical distri- bution are recognized as the farmer's friends; FIC. 105. — HOUSE WREN (Troglodytes a-don'S. (United States Department of Agriculture.) among them are the robin, oriole (Fig. 117), mocking-bird, brown thrasher, chickadee, and catbird. But there is another class of birds which is much persecuted because the farmer errone- 310 AGRICULTURE. ously considers them his enemies. To this class belong the crow, the blackbird, and- many species of hawks and owls.* Examination of the stomach contents of many of these birds has proven that they are more beneficial than harm- ful, destroying many insects as well as injurious rodents, such as mice and gophers. Again, some birds eat more or less weed seed throughout the year, even when insects are abundant. But their work practically extends from early autumn until late spring. During cold weather most of the birds about the farm feed extensively upon seeds. It is not uncom- mon for a crow blackbird to eat from thirty to forty seeds of smartweed or bindweed, or a field-sparrow one hundred seeds of crab-grass, at a single meal. In the stomach of a Nuttall's sparrow were found three hundred seeds of amaranth, and in that of another three hundred seeds of lamb's-quarters ; a tree-sparrow had consumed seven hundred seeds of pigeon-grass, while a snowOake from Shrewsbury, Mass., which had been breakfasting in a garden in February, had picked up one thousand seeds of pigweed. Among the weeds which are troublesome in fields, especially among hoed crops, may be mentioned ragweed {Ambrosia artemisics folia), several species of the genus Polygonum, includ- * Year-book, 1897. FIG. I06. FOUR COMMON SKEU-EATIXG BIRDS. a — Jiinco. 5— White-throated Sparrow, c — Fox-sparrow, d — Tree-sparrow. 311 312 AGRICULTURE. ing bindweed (/*. couvo/vii/iis), smartweed (^P. lap at hi folium^, and knotweed {P. aviculare), pigweed {^Amarantus I'etroflexiis and other spe- cies), nut-grass and other sedges {Cyperaceci), crab-grass {Paiiiciun sangitinale), pigeon-grass (^CJia'tocloa viridis) and (C gla2ica), lamb's-quar- ters [Cheitopoditim album), and chickweed [Al- sine media). Every one of these weeds is an annual, not living over the winter, and their seeds constitute fully three-fourths of the food of a score of native sparrows during the colder half of the year. Prof. F. E. Beal, who has carefully studied this subject in the upper Mis- sissippi valley, " has examined the stomachs of many tree-sparrows and found them entirely filled with weed seed, and concluded that each bird consumed at least a quarter of an ounce daily Upon this basis, after making a fair allowance of the number of birds to the square mile, he calculated that in the State of Iowa alone the tree sparrow annually destroys about 1,750,000 pounds, or about 875 tons, of weed seed during its winter sojourn." '' On a farm in Maryland " tree-sparrows, fox- sparrows, whitethroats, song-sparrows, and snow- birds fairly swarmed during December in the briers of the ditches between the corn-fields. They came into the open fields to feed upon * Quoted from the Year-book, 1898: " Birds as Weed Destroy- ers." From Ye.ir-book, 1898. FIG. 107. — FOUR COMMON WEEDS, THE SEEDS OF WHICH ARE EATEN KY BIRDS. a — Amaranth, d— Crab-grass, r— Ragweed, d — Pigeon-grass. 313 314 AGRICULTURE. weed seed, and worked hardest where the smart- weed formed a tanorle on low ground. Later in the season the place was care- fully examined. In one corn-field near a ditch the s mart w e e d formed a thicket over three feet high, and the ground beneath was literally black with seeds. Examination showed that these seeds had been cracked open and the meat removed. In a rectangular space of eight- een square inches were found 1,130 half seeds and only two whole seeds. Even as late as May 13 the birds were still feed- inof on the seeds of these (I— Bindweed. /^-I^ambs-quarters. and Other WCeds lu the c— Purslane, rf- Amaranth. ''~ r i i > > ^ \ i Spotted spurge. /-Ragweed. ^— UeldS. ' A SearCll WaS Pigeon-grass. /,-Dandelion. ^^^^^^ ^^^ ^^^^^ ^^ VarioUS weeds, but so thoroughly had the work been done that only half a dozen seeds could be found. The birds had taken practically all the Year-book, 1S98. FIG. lOS. — WEED SEEDS COM- MONLY EATEN BY BIRDS. * Quoted from the Year-book, 1S9S: " Bird.s as Weed Destroy- ers." ENEMIES OF PLANTS. 315 seed that was not covered. The song-sparrow and several others scratch up much buried seed. No less than fifty different birds act as weed destroyers, and the noxious plants which they help to eradicate number more than threescore species. Some, the blackbirds, the bobolink, the dove, and the English sparrow, in spite of their grain-eating proclivities, do much good by consuming large quantities of weed seed. Horned larks, cowbirds, shore-larks, and gros- beaks also render considerable service, while the meadow-lark is even more beneficial. The " quail as an enemy of insect pests and destroyer of weed seed has few equals on the farm. Goldfinches destroy weeds not touched by other birds, confining their attacks chiefly to one group of plants (the Compositse), many of the members of which are serious pests. But the birds which accomplish most as weed destroyers are the score or more of native sparrows that flock to the weed patches in early autumn and remain until late spring. Because of their gre- garious and terrestial habits, they are efficient consumers of the seeds of ragweed, pigeon-grass, crab-grass, bindweed, purslane, smartweed, and pigweed (Fig. io6). In short, these birds are little weeders whose work is seldom noted, but always felt." "* * Quoted from the Year-hook, i8g8 : " Birds as Weed Destroy- ers." 316 AGRICULTURE. When one considers, then, that the greater per cent, of the food of birds is composed of in- sects, and that of the vegetable material they consume a large per cent, is weed seed, and that they obtain fully one-half of the grain they do eat from the waste of the feed-yard and other places, and this largely in the winter months, FIG. 109. — "LOOK OUT when insects are scarce, it will be realized that the best and cheapest means of keeping insects in check is the encotiragement and protection of birds. It would be cheaper to allow the birds a portion of the grain or fruit than to allow the insects to take all, which would happen ENEMIES OF PLANTS. 317 in a few years if the birds were extermin- ated.* " What! would you rather see tlie incessant stir Of insects in the windrows of the hay, And hear the locust and the grasshopper Their melancholy hurdy-gurdies play ? Is this more pleasant to you than the whir Of meadow-lark, and her sweet roundelay, Or twitter of little field-fares, as you take Your nooning in the shade of bush and brake ? " You call them thieves and pillagers; but know, They are the winged wardens of your farms. Who from the cornfields drive the insidious foe. And from your harvests keep a hundred harms ; Even the blackest of them all, the crow, Renders good service as your man at arms, Crushing the beetle in his coat of mail. And crying havoc on the slug and snail." — The Birds of Killifigworth, Longfellow. 2. Predaceoiis Insects. — Predaceoiis insects, or those that prey upon or eat other insects, are also helpful to the farmer. (i) Specific Examples. — Among the most useful of these insects are several species of ladybugs {Coccincllidcr). Both the adult and larval forms feed upon * It would be a profitable investment to plant out some Russian mulberry-trees on purpose for the birds, or to grow in waste places and corners such plants as hemp and sunflowers, allowing them to stand throughout the winter as supplies for the birds when food is scarce. 318 AGRICULTURE. plant-lice and scale insects. The ladybugs are small, rather pretty, turtle-shaped beetles nearly always bright colored (orange or red), with jet black spots upon them, or black with white, red, or yellow spots (Fig. I lo). This bright color is a warning to the birds that these bugs are un- pleasant to the taste ; hence, they are seldom eaten by the birds. The larva is equally protect- ed by its terrifying ap- pearance, since it is cov- FiG. \\o.—Anatisis-pu)ictata, ered with long or sharp , , '. spmescriP^. wo a). (After Riley.) r V & / The ladybugs are very common, and are found upon plants infested with plant-lice and scale insects (Fig. 1 1 1). The fruit growers of California prevented the de- struction of their orchards by importing a species of ladybug from Australia to prey upon these scale insects.* But there are enemies in the camp : three species of ladybugs are injurious to plants. One species (Fig. 112), in both larval and adult stages, devours the leaves, flowers, and green pods of the bean. Another species feeds upon * The United States Division of Entomology has imported a Chinese ladybug to prey upon the San Jose scale. ENEMIES OF PLANTS. 319 KIG. ITI.- -1 ADYBUG AND LARVA PREYING UPON SCAl.K INSECTS INFESTING A I'EAR. (After Howard and Marlatt, Division of Entomology, Department of Agri- culture, Washington, D. C.) squashes, melons, and cucumbers. This beetle is yellowish in color with big black spots, and is slightly pubescent.;^ The larva is also yellow and covered with forked spines. Lace-winged Fly. — Another strong ally in fighting our insect foes is the common lace )fe»i'-book 1898. FIG. 112. — Epilackna corrupts. a — lyarva. ^—Beetle, c— Pupa, rf— Egg mass. All about three times natural size. 320 AGRICULTURE. winged fly, or Aphis lion (Fig. 113, a). It is a beautiful little creature, with brown antennae and large, lustrous, golden eyes. Its body is of FIG. 113. — CHRYSOPA SPECIES. (After Brehm.) a pale green color, as are also its wings of deli- cate lace. Its attractive appearance, however alluring to the birds, is protected by a disagree- able odor. The eggs, laid in clusters, each Ggg upon a white, threadlike stalk, look like a diminutive grove (Fig. 113,^). This stalked ENEMIES OF PLANTS. 331 arrangement is to prevent their being eaten by larvae, not only of other insects, but of those of their own family, for they are veritable cannibals. The larvae ( Fig. 1 13, (^) are as ugly as the adult is beautiful. They are active, spindle-shaped little fellows with crescent- shaped mandibles, which never seem to tire of piercing to death all insects they can capture ; but they are particularly de- structive to plant-lice (aphides), and for this reason are often called f-^ aphis lions. They hold their prey be- tween the tips of their '•'<"•• im- — ichneumoi ^ I'OSITING AN EGG WITHI mandibles, and suck the juices through the long tubes formed by a groove along the under side of each mandible and the slender maxilla which fits into it. When this larva reaches its growth it rolls itself into a ball and spins a cocoon of snowy white, from which it comes forth through a circular lid (Fig, 113,/") a wondrously changed creature — the dainty lace- winged fly. Another group of our insect friends is the parasitic Hymenoptera, such as the ichneumon- N-FLY DE- N COCOON. (Slightly magnified.) 322 AGRICULTURE. flies, Chalcis flies, and braconids. These generally lay their eggs in or on the body of the larva of other insects, but sometimes they deposit them in the adult, the pupa (Fig. 1 14), or even the Ggg. When the eggs hatch, the larvae feed upon the substance of the host, thus destroying it, to- gether with all of its posterity, which in a few years might have been countless. One genus of the ichneumon-flies which is often mistaken for an enemy of plants is the thalessa, a yellow or black (according to the species) insect, with a long, slender, though powerful, ovipositor, with which it pierces into the wood of a tree. It will be found upon ex- amination, however, that the tree is infested with borers ( Fig. 122), and that what the ichneu- mon really does is to deposit its eggs in the nest of the borer, where the larva, when it hatches, fixes itself to the body of the borer, liv- ing upon its juices and gradually killing it. The many species of Chalcis flies, as well as the ichneumon, are parasitic upon a great num- ber of different insects, one species feeding upon the chrysalis of the cabbage-butterfly.'-' (2) Exercise 14. — {a) As many kinds of these insects as can be obtained should be placed in the breeding-jars and watched through their development. {b) Experiment with the food of these insects in dif- ferent stages of their development to ascertain in what stage they are predaceous and wliat insects they will eat. * The larvae of Syrphus-flies do much good by destroying scale insects and aphides, in whose colonies they live. ENEMIES OF PLANTS. 323 (c) It will be interesting and instructive to place the larva and the adult forms of the ladybug, and of the lace-winged fly in the breeding-jars, and supply them with portions of plants infested by aphides, and watch what takes place. (d) In which of these stages did your specimen of ladybug devour the plant-lice ? How ? {e) In which of these stages did your specimen of lace- winged fly devour the plant-lice ? How ? XI. Specific Examples of Injurious Insects. I. Plant-lice are among the most familiar and most annoying of the insects injurious to plants. The family includes many species, all of which are small, the largest measuring only one-fourth inch in length. Most of those we see are wing- less, but some of the common species have two pairs of transparent wings. Our most common species of plant-lice are green or black, but others are red, brown, or yellow. The beak is three-jointed. It is not coiled up like that of the butterfly, but is attached to the head by a hinge, and is bent up against the under side of the body when the insect is not feeding. They feed upon the buds, leaves, and tender growing stems or roots of plants, and in such immense numbers as to often do much damage. Exercise 15. — It will be easy to find colonies of these plant-lice upon crysanthemums, cherry, or plum sprouts, or even roadside weeds. {a) Watch them closely, taking care not to dis- turb them. What other insects do you see among theni ? Do you find two tiny tubes projecting from the 324 AGRICULTURE. terminal segment of tlie abdomen of the plant-louse ? Is there a drop of honeydew on the tops of these tubes ? What do you find ants doing with this honeydew ? If no honeydew is present, observe the ants stroke these plant-lice with their antennae. Do they then obtain the honeydew (Fig. 115) ? This process is commonly spoken of as the "ants milking their cows." Bees and wasps also like this honeydew. Ants care for the plant-lice in many ways, protecting their eggs and carrying the lice to the roots, upon which they feed. (^) Do you find any enemies in the colony ? {c) Kerosene emulsion is, perhaps, the best remedy. Why? (d) Will the Paris green spray kill them ? Explain. 2. T/ie Roses lug [Monosiegia rostri") is a soft- bodied larva, green above and yellowish below, which eats the surface of the rose leaves, leaving only the framework. When full grown the larva buries in the ground. The adult is a tiny black fly with dull-colored wings, and with the first and second pair of legs grayish. There are two broods a year (one in early summer and one in late summer), the second brood pupating in the ground over winter, and the adult emerg- ing in the spring. Either Paris green or kero- sene emulsion will form an effective remedy. Why? 3. Tent-caterpillar. — There are several species of tent-caterpillars ; but only two, the apple tent-caterpillar i^Clisiocanipa americana), and the forest tent-caterpillar (^Clisiocampa ENEMIES OF PLANTS. 325 disstj'-ia) are common in the United States east of the Rockies. The adult form of the C. amci'icana is a rather small, rusty brown moth, with oblique, pale yellow lines across the four wings (Fig. 1 16). The eggs are laid in summer in a circular KIG. 115. ANTS MILKING PI.ANT-I.ICE. (After Figuir.) band about a twig. This band of eggs {Fig. 116, c) is protected from the weather by a sticky substance with which the parent moth coats them over. The following spring, just before leaf buds open, these tiny caterpillars come 32G AGRICULTURE. FIG. Il6. — AMKRICAN TENT-CATEK I'lL- l.AR (Clisiocampa americana).^ forth to feed upon the buds, and soon the colony, for they are social beings, spins a silken web, or " tent," on the fork of a branch (Fig, 1 16, a to b), to which the cater- pillars retire at night and in cold and stormy weath- er. They grow rapidly, and greed- ily d evo u r the leaves as they come out, doing much damage. When the cat- erpillars are grown ni worms on the outside of they are about two the tent, c — Egg-niass, with the gummy cover- a and i^— FuU-growr ing removed. (/—Cocoon, containing the chrys- incheS lonoj' and alis. Above all, the moth. , • 1 1 • (After Riley.) covered With hairv * Our Western species Clisiocampa fragilis) U ,- ,' c t 1 <=> c T^Vip>ir resembles the above so closely that the figure OriStieS. 1 ncy serves equally well for it. 111 • 1 are black with a white stripe down the median line, and with short yellow lines and pale blue spots on each side (Fig. ii6, a and 8). When they have reached their growth they leave the tree, seek ENEMIES OF PLANTS. 327 shelter on the ground under boards, bark, etc., and spin a silken cocoon (Fig. ii6, a), from which, after a few weeks, the moth emerges. The apple and wild cherry are the trees most usually attacked by these caterpillars, but they FIG. 117. tALTIMORE ORIOLE ATTACKING THE NEST OF THE AMERICAN TENT-CATEK PILLAR. have been found upon the peach, rose, and other members of this family of plants, as well as upon forest and shade trees. Bacteria and parasitic ichneumon-flies, as well as many birds, such as cuckoos, blue jays, crows, 328 AGRICULTURE. and orioles (Fig. 1 1 7), serve as natural checks to these insects, but they are by no means sufficient to prevent them from doing great damao^e. Every farmer should take prompt measures to destroy them at their first appearance upon his trees. This may be done effectively by spraying the foli- age with arsenate of lead, or Paris green, or by collecting them in their tents early in the morning or late in the evening. This may be done by thrust- ing into the tent the end of a long pole, into which has been driven two or three nails, and turning the pole round and round FIG. 118.— FOREST TKNT-cocooNs SO as to twist the web IN APPLK LEAVES. , . r^^, about It. 1 he cater- pillars should then be burned or crushed. 4. T/ie Forest Tent-caterpillar ( C. disstria) is very like the American tent-caterpillar in appearance and habits. The markings upon the wings of this moth are dark instead of light, while in the caterpillar (Fig. 119) the median line is ENEMIES OF PL-VNTS. 329 marked with a row of white spots instead of a continuous line of white, as in the avicj^icana. In the colonies or masses which they form FIG. 119. — FOREST rENT-CATERriLLAKS FEEDING Ul'OX ELM LEAVES. when not feedingf there is a more or less dis- tinct web underneath them, but it does not form a complete covering above them, as in the amcricana. They not only eat away consider- 330 AGRICULTURE. able portion of the leaf, but they cut it in two, so that the end falls to the ground ; in this way the damage is doubled (Fig. 119). To this is also added the injury done to the foliage by binding up the leaves (Fig. 118) for the attach- ment and the protection of the cocoon. FIG. 120. — CODLTNG-MOTH. a — Injured apple. — b — Place where egg is laid. e — Ihic<; of h)W-^rowIn^ shrubs alon<^ the walls and in the angles of north(;rn exposures, nothinj^ is more beautiful than ferns IK.KNS AN'I) nil, OX. with their feathery fronds (I'ig. 143), which can Ix; us(;d so effectively in house decorations. When it ])ecomes necessary to have a fence or a hcd^e there are many shrubs adapted for this purpose — as. roses, barberries, japonicas, bush honeysuckles, privets, arbor-vita^s, elder bush('s, sumachs, and a dozen others. If several kinds of these shrubs are allowed to form a con- tinuous yet irregular band, Ixtcoming broader fc :2 cfl SCHOOL AND HOME GROUNDS. 379 in one place and higher in another, and in the background merging into a clump of tall shrubs or small trees, the effect will be much more natural than the closely sheared, stiff hedge. Where a number of varieties, species, or genera of varying habits are brought together in a group of shrubbery, the effect produced by the shades of differences in form and color and texture is usually more pleasing than that of a group formed from any one kind alone. For screens and masks, tall-growing, graceful shrubs should be used for the background or the center of the mass, and the outlines should gradually lose themselves in the lower plantings and green sward (Fig. 144). The plantings must be dense enough to conceal the view and to hide all trunks. Neither trees nor shrubs should expose long, bare trunks, making them look as though they were upon stilts. For this reason it is better to plant thickly, and cut out some shrubs when they need thinning. In massing shrubbery, again the gardner needs to know his plants. He should know those that first put forth their leaves in spring, the time of blooming, and the character of flowers and fruit. In general, mass those shrubs with the darker, restful colors in the background and those of lighter shades in the foreground. Those forms that blossom successively should be selected, for 380 AGRICULTURE. it is in this constant chano-e that we have one of the chief charms of the garden. As to material, the common native shrubs are really the best. Dogwoods (Fig, 145), elders, crab-apples, Judas-trees, sumachs, buckberries^ snowberries, wild roses, greenbriers, honey- suckles, currants, spice-bushes, and button- bushes — all are beautiful, each in its season. Besides these native plants, there are scores of beautiful and inexpensive ones to be had — as, the lilac, mock-orange, barberry, japonica, snow- ball, spirea, deutzia, hydrangea, weigelia, and many beautiful varieties of roses. There are multitudes of hardy climbers and annuals that may be used over porches, arbors, and against the bare masonry of buildings. For example, the climbing rose, honeysuckle, wistaria, Virginia creeper, clematis, trumpet- vine, wild grape, and hop-vine. Such annuals as cypress, Madeira, cinnamon-vine, wild cu- cumber, morning-glory, and moon-vine may often be used to advantage. Not all climbers will look well together, nor be suited for all places. Each has a special charm and beauty of its own, determined by its habit of growth, and the character of its flowers and foliage. Hardy climbers are more effective in uniting the lawn and walls of the house than annuals, which are present for a season and then gone, leaving not only the junction of the soil FIG. 145. — DOGWOOD IN FLOWER. 381 382 AGRICULTURE. and walls bare^ but the work to be done over again the next year. Flowers. — While lawn, trees, and shrubs are the main features of our plantings, the flowers must not be forgotten. True, many flowers will be had from month to month from the shrubs, if they have been rightly chosen. But some flowers must be grown, not so much for the sake of the picture "as for their own sweet sake." First, let flowers of the wild-wood be planted. Let violets of all kinds, sweet-williams, blue- bells, anemones, spring beauties, or dog's-tooth violets peep out from shady recesses among the grass and shrubbery. The old-fashioned flowers, such as phlox, poppy, marigold, pink, petunia, verbena, and portulacca, must not be forgotten. These are appropriate for the flower garden proper, but should not be scattered over the lawn to dis- figure it. "I have in mind a garden old, Close to a little-known highway, Where aster, pink, and marigold Keep their long summer holiday. 'Mid dreams and visions manifold I have in mind a garden old. " The fragrance of old-fashioned flowers. Where hollyhocks and daisies blow. Floats on the wings of summer showers Across the fields of long ago. Lo! from the sweet, rose-ripened bowers. The fragrance of old-fashioned flowers." — Frank Walcott Hutt. SCHOOL AND HOME GROUNDS. 383 Asters, chrysanthemums, pansies (Fig. 146), nasturtiums, and California poppies afford flow- ers for cuttino, but do not o^row them in beds outside of the tiower garden. Rather let them lill irregular nooks at the edge of the shrubbery, FIG. 146. PANSIES. and shrub and tiower will each enhance the beauty of the other (Fig. 144). Bulbs may be used in much the same manner as other flowers, and the season of blossoms be greatly advanced. The flowers from many bulbs are of surpassing beauty — as, the tulip, jonquil, and the lily-of-the-valley. Two others that are most pleasing when dotted here and there over the lawn are those cheery little harbingers of spring, the crocus and the un- 384 AGRICULTURE. assuming- little snowdrop, the most welcome of all. Temporary Screens. — If screens are needed for a season, what could be more beautiful than -SHALL THE CHILDREN PLyCK >XOWERS OR RATTLE TIN CANS IN THE BACK YARD? the tall sunflowers flanked by bashful golden- rods, with their torches of shining gold? If anything could be more beautiful, it is these same plants, now robed in duller hue, casting 386 AGRICULTURE. their outlines against the winter sky, and nod- ding a welcome to the birds who come to par- take of their bounties — or blossoming again, this time in snowy whiteness. Hollyhocks, castor-beans, cosmos, dahlias, chrysanthemums, and asters also make effective FIG. 149. — A BOUQUET OF SWEET PEAS. back-yard screens (Fig. 147), as do also sweet peas, morning-glories, moon-vines, wild cu- cumbers, and Madeira-vines, if furnished with a support. Here, as in other plantings, one, by rightly choosing from among the myriads of tall-growing plants or vines, may have an abun- dance of flowers throughout the season. Among annual climbers, sweet peas should be given the preference, since they furnish an abundance of fragrant flowers (Fig. 149) for decorating the SCHOOL AND HOME GROUNDS. 387 rooms and table from June to October, if the flowers are picked regularly and the seed pods not allowed to form. The vines should be given a support as soon as the tendrils appear. Wire netting makes a good and durable sup- port for sweet peas. Water. — If the possibilities of a place include water in the form of rivulet, stream, or pond, the owner is indeed fortunate. Running water enlivens a landscape ; still water renders it peaceful and quieting. Along the wooded banks of the brook one expects to find " tangles of vines and branches and brakes." The pond or small lake, itself a thing of beauty, offers unusual opportunities for the skill of the gardener. Ash and sycamore and willow and alder are looked for along its banks, and it is surely a disappointment if none of them are mirrored in its silvery surface ; for the reflections in the water (Fig. 150) are the best part of the picture.* A pond may simply look like a "cup set in the orround," or form the most beautiful and es- sential part of the picture. A fringe of willows may overhang its banks here and there. At other points the grass and rushes should quench * Before leaving the subject, the student should be required to draw an original design for a geometrical style and one for the natural style of landscape-gardening. These plans should be carefully worked out in ink on good paper and discussed in class. 388 SCHOOL AND HOME GROUNDS. 389 their thirst in the water's brink, while " further along the sedges and cattails may jut far out into the still water," upon the surface of which quietly rests the lily pads (Fig. 150). C— REFERENCES. " Plants as a Factor in Home Adornment." Year-book, United States Department of Agriculture, 1902. Cornell Nature-Study Quarterly^ No. 2. Part II., Fifteenth Annual Report, Agricultural Experiment Station, Kingston, Rhode Island. " Landscape Gardening." W. A. Waugh. igo2. 4. "Art Out-of-Doors. ' Mrs. Van Rensselaer. Charles Scrib- ner's Sons, N. Y. 1900. " How to Plant the Home Grounds." S. Parsons, Jr. Double- day & McClure Co., N. Y. 1S99. " In God's Out-of-Doors." Quayle. Jennings & Pye, Cincin- nati. OUTLINE OF CHAPTER XIV. FARM ANIMALS. E. A. TROWBRIDGE, Animal Husbandry, Unhiersity of Missouri. y^.— GENERAL PRINCIPLES. I. Early History. II. Improvement. III. Heredity. IV. Variation. 1. Atavism. 2. Ordinary Variation. 3. Extraordinary Variation. V. Selection. 1. Natural Selection. 2. Artificial Selection. VI. Functions of Animals Under Natural Conditions. VII. Changes Wrought by Man. VIII. Relation of Form and Function. ^.—HORSES. I. Light Horses. 1 . Type. 2. Breeds. II. Coach-Horses. 1. Type. 2. Breeds. III. Draft-Horses. 1 . lype. 2. Breeds. C— CATTLE. I. Beef-Cattle. 1 . Type. 2. Breeds. 391 392 AGRICULTURE. II. Dairy-Cattle. 1. Type. 2 . Breeds. III. Dual- Purpose Cattle. 1 . Type. 2. Breeds. ^— SHEEP. I. Mutton Form. II. Wool Form. (a) Fine Wool Sheep. 1. Type. 2. Breeds. (b) Medium Wooled Sheep. 1 . Type. 2. Breeds. A— SWINE. I. Lard Hogs. 1 . Type. 2. Breeds. II. Bacon Hogs. 1. Type. 2. Breeds. A— POULTRY. I. Laying Fowls. 1. Type. 2. Breeds. II. Meat Fowls. 1 . Type. 2 . Breeds. III. General- Purpose Fowls. 1 . Type. 2. Breeds. G^.— REFERENCES. CHAPTER XIV. FARM ANIMALS. E. A. TROWBRIDGE. Animal Husbandry, University of Missouri. I. Early History. The early history of domestic animals is as much in obscurity as that of the human race. Biblical references to some classes lead us to believe that they were known at a very early date. The findings of recent investigators tend to prove the existence of prehistoric ani- mals closely akin to some of our present domestic animals, particularly the horse. These prehistoric horses were very small and different from the horse of to-day in having two or more toes instead of the hoof, and their teeth were much less developed. Their color was probably more or less striped, resembling the zebra. Just when our domestic animals were brought into close relation with mankind is uncertain, but it is a certainty that it was at a very early date. They were first used for food and their hide for clothing. Later, the horse and ox were used as beasts of burden, and the horse was of great aid in warfare. 393 394 AGRICULTURE. II. Improvement. As time went on people became more civi- lized. Their habits, customs, ambitions and demands chanored. With this change in the people themselves many changes in domestic animals followed, as a natural consequence. It was a g-eneral changre in the direction of im- provement, although this was not always the case. There are three natural laws which are g-reat factors in affecting animal form and character in its reproduction, and make change possible. They are 1. Heredity. 2. Variation. 3. Selection. III. Heredity. Ribot defines heredity as " that biological law by which all living beings tend to repeat them- selves in their descendants." This is the law which makes possible the resemblance between a parent and offspring, and is well expressed in the common saying that " like produces like." It is this principle upon which we depend for the transmission of milk-producing quali- ties in dairy cattle, speed in race-horses, etc., and by which we are able to maintain a standard of breed, characteristics or type in animals. FARM ANIxMALS. 395 IV. Variation may be defined as the tendency in animals to produce characters in the offspring which differ from those of the parents. This law has given rise to the common expression that " like does not always produce like." At first sight these two principles would appear antagonistic ; but upon further study their difference may be understood. As the result of reproduction of animals of a certain breed, we expect offspring which re- semble the parents in general breed characters. For example, it is natural to expect an Abcj-dcen Angus cow to be the mother of a hornless calf, black in color and of meat-producing confor- mation ; and we will not expect her to be the mother of a fawn-colored calf with horns and capable of milk production at maturity rather than beef production. Thus, within limits, " like produces like." On the other hand, we would not expect this calf to be exactly like its mother in every respect, for who has ever seen two animals or two people exactly alike ? The calf might differ from its mother in size, spring of ribs, thickness of loin, length of legs, depth of body and various other ways. Thus, we see that like does not always produce like. Should the calf differ from its mother in these minor details, this variation would be called gradual or ordinary variation. But should it possess some 396 AGRICULTURE. of the characteristics mentioned as unexpected the difference would be called spontaneous or extraordinary variation, and might result from many different causes. Animals that have been bred for a long time with a certain type in view are more likely to produce animals of that type than are those animals that have come to this desired type by differing greatly from their parents. Thus, one of the values of pure-bred animals is their ability to reproduce themselves with a greater degree of accuracy than animals which have not been bred pure. 1. Atavism. — It sometimes happens that ani- mals are born with one or more characteristics which were not possessed by their parents or grandparents, but which were possessed by their ancestors many generations prior to their existence. This inborn tendency of animals to revert to their original type is called atavism, or reversion. 2. Ordinary Variation, for the most part, is caused by some of the many factors of environ- ment. Among these factors are food, climate, soil, exercise and general management. Food is one of the most important among them. Ample food supply is necessary to the maximum growth of animals, yet overfeeding leads to sterility and lack of vitality in offspring. A striking example of the effect of nutrition upon FARM ANIMALS. 397 animals is the Shetland pony, a very miniature horse in his original home, but gradually in- creasing in size when taken to a country of liberal food supply. As an illustration of the effect of climate on animals, one may observe the Galloway cattle of western Scotland. They have developed a remarkably heavy coat of hair because of the cold and stormy weather to which they have been subjected. Domesticated cattle receive their food with very little exertion other than that of eating, while the buffalo of the Western ranofe has been forced to cover considerable territory to find sufficient food. This continuous exercise, along with the severe weather endured, has brought about the lack of thick fleshing quality and the extraordinary constitution of the latter animals. 3. The causes of Spontaneous or Extraordi- nary Variation are not well understood. It is known, however, that this type of variation is transmitted only very irregularly. Selection may be divided into two classes ; namel}', natural selection and artificial selection, yet the latter has certain limits put upon it by the former. V. Selection. By Natural Selection is meant the repro- ducing of animals most capable of self-protec- tion, of subsisting and again reproducing under existinof conditions. It is what has been called 398 AGRICULTURE. the natural law of the "survival of the fittest." Among cattle those animals capable not only of protecting themselves in battle, but of destroy- ing the enemy, which might be weaker animals of their kind or of a different kind, were the survivors and remained to reproduce them- selves. Those individuals not able to withstand the hardships of a severe climate either starved, froze or were killed by their stronger brothers, who fought with them to obtain the available food. The buffalo, with heavy head, neck, strong fore-quarters and muscular but light hind-quarters, has this conformation ; because it permits of greater strength and agility, he is able to destroy his enemy and to move about to obtain food. Artificial Selection is the mating of animals controlled and directed by men. By careful study great breeders have developed our modern breeds of live stock. They have created types which were most efficient in particular lines of production and, in fact, have changed the form and function of many of our domestic animals. VI. Primary Functions of Animals. It will thus be seen that the laws of nature are at the very basis of all life. The first function of animals is self-preservation. For FARM ANIMALS. 399 preservation, the ability to gather food and to protect themselves against other animals and the climate, is necessary. The second function of animal life is that of reproduction, which is dependent upon general strength and vigor. Animals in their natural state have developed temperament, conformation and qualities that best fit them for the performance of these life functions. But under domestication oreat chanj^es have been wrought. Here to only a limited extent may we say that animals exert themselves for self-preservation. Their food, shelter and pro- tection from other animals is supplied by man. In domestic animals the process of reproduction is largely directed by man, consequently they have been relieved to some extent of the primary functions of their existence. VII. Changes Wrought by Man. Man, however, expects remuneration for his labor and his pains and seeks to obtain it in one form or another. He not only lessens the responsibility of domestic animals of their own preservation and reproduction, but seeks by proper nutrition, care and selection to develop them to a high efficiency along a given line. As an example of this development, one may note the dairy-cow. Observation taught that some animals produced more milk than others. Basing the procedure upon the law of heredity, 400 AGRICULTURE. these high-producing animals were allowed to reproduce themselves. Their ability to produce milk was increased by proper care and feeding. From each succeeding generation the best cows were selected and allowed to reproduce, the methods of feeding and caring for them were improved, until we have the dairy-cow of to-day, a veritable milk-producing machine. Further illustrations of man's efforts to in- crease the efficiency of domestic animals may be observed in the trotting-horse, the lard hog, the wool-producing sheep ; in fact, all classes of domestic animals. Thus, through these factors of food, care, selection and general management, prompted by man's necessities and his desires, the various classes and breeds of live stock have been developed. They have, however, been de- veloped under vastly different conditions and in widely separated locations. The development of various classes in their respective locations has been due to environment and the demands of the people. The beef-cattle business on the open range developed there because of the vast amount of cheap and government lands which might be pastured. The scarcity of help and markets, and the vast amount of land and cattle which must be under the supervision of one man, forbade the pursuit of any but an exten- sive business. Quite opposite are the conditions FARM ANIMALS. 401 surrounding- our large cities. The vast popula- tion creates a demand for milk. The high price of land prohibits the owning of large tracts by individuals, and the dairy business is capable of enormous profit per acre. Hence we see to-day the districts within reach of our cities attentive to that branch of agriculture. To make the dairy business profitable, high- class dairy-cattle are necessary. The draft-horse in the Northern United States is the result of a demand for animals to do heavy work in the timber, on the streets of the cities, and in the large fields. The heavy soil and bad roads in Virginia and Kentucky brought about the development of the American saddle- horse. Many other instances of similar char- acter mio^ht be cited. But without proper care all these improved classes of animals tend to revert to their natural conditions, under which they can protect and re- produce themselves with the greatest certainty. It is this retrogression that man guards against by selection, care and management of his live stock. VIII. Relation of Form and Function. It has been observed that animals possessing great efficiency in some one direction have cer- tain characteristics in common. This is true whether they have been developed independ- ently or in close touch with each other. As 402 AGRICULTURE. an example of this we have the draft-horse in England, and the draft-horse in Europe, de- veloped to a great extent independent of each other, yet possessing many characteristics in common. Some of those characteristics com- mon to both are weight, temperament, size of bone and general conformation. These coincident cases found in all classes of live stock have given rise to ideas regarding the "relation of form and function." To just what extent form and function are related is difficult to discern. Factors such as temperament and invisible characteristics have a great effect in determining the efficiency of animals. But that animal form and temperament are an index to their function and efficiency, within limits, can not be doubted. Examples of this may be ob- served in all classes of live stock with which we are concerned. From the following paragraphs the relation of the various forms and tempera- ments in the different classes of live stock to their function and efficiency will be seen. There are certain terms by which we refer to characteristics which are common to all animals; namely, quality, conformation, constitution, temperament, capacity and early maturity, and sex character. I. Quality is an indefinable characteristic which shows strength and ability for perform- ance without coarseness, and is indicated in FARM ANIMALS. 403 animals by symmetrical development, clean-cut features, strong, closely knit bone, well-defined joints, pliable elastic skin of medium thickness and fine hair, all of which go to make up an ap- pearance of general refinement. 2. Confoi'niation refers to the skeletal and muscular structure and development of animals. 3. Constitution refers to the physical powers of animals, their ability to withstand hardship and disease. It also refers to their ability to remain healthy and produce well on heavy rations. It is indicated by a broad, deep chest, a well-proportioned head, and a clean-cut muzzle of medium size. A sleek coat of hair, bright eyes, and alert temperament indicate thrift and general good health. 4. Temperament is the characteristic of ani- mals indicating nervous control and ability and disposition to do work. It is indicated by clear eye, graceful carriage, style and vigor in action. Terms commonly applied to temperament are lymphatic, nervous, sanguine and bilious. 5. Capacity is ability of animals to utilize food for the production of milk, meat, wool, speed or strength, as the case may be. It is indicated by good appetite, depth and width of barrel (well-developed digestive apparatus), and disposition to utilize food. 6. Early Maturity is a term applied to the 404 AGRICULTURE. tendency of animals at the present time to reach mature form and begin their life's work at an early age. 7. Sex Character has reference to the femi- nine features and the quiet disposition of females ; the strength, aggressiveness and mas- culinity of male animals. Animals which are clearly lacking in sex character do not usually prove valuable in a herd of live stock kept for breeding purposes. From the followincr discussion will be seen the various classes of live stock, the division of these classes into certain rather well-defined types and a subdivision of these types into breeds. The descriptions are those of the most efficient animals which are recognized by au- thorities on the various classes of stock. ^.—HORSES are classified according to their uses to a great extent. Light Horses are those used for light driving, road work and riding. Coach-Horses are used for drawing fashion- able turnouts and carrying fine harness. They are also used as general-purpose horses. Draft-Horses are used to perform heavy work of any kind when strength and weight are required. FARM ANIMALS. 405 I. Light Horses weigh from 900 to 1,200 pounds ; stand from 15 to 16 hands high, the larger ones being pre- FIG. 151. — " ARIIST MONTROSE." Sweepstake Saddle Stallion, at World's Fair, Chicago, 111., Sept. 6, 1893. Ridden by JefT Bridgford. ferred. They are somewhat angular in con- formation, with muscles of extreme length rather than thickness. Symmetrical develop- ment throughout is essential. The head should 40() AGRICULTURE. be of medium size, carried well up, with a grace- ful neck of medium length set on long sloping shoulders. A short, strong back with long rump and tail set high are desirable. The legs should be set squarely under the body. The skin and hair should be fine, the bones and joints of good size and well defined, giving a general appearance of quality and good breed- ing. Constitution and lung capacity are indi- cated by nostrils of medium size, by a well- defined windpipe and a deep chest of medium width. A temperament showing spirit and vigor yet tractability is desirable. Without this spirit, the high and vigorous action so essential to a light horse is impossible. Both at the walk and at the trot the gait should be regular, straight and springy. These horses are re- markable for their stamina and endurance. BRF.EDS OF THIS CLASS. 1. Arabians, which are a very old breed; native of western Asia and Africa. They are particularly characterized by their intelligence and endurance, and have had marked influence on the horses of to-day through the English Thoroughbred. 2. TJioroughb7'eds, which had their origin in England and have long been used as race (running) horses. They have been of great value in improving the quality and stamina of FARM ANIMALS. 407 some of the more modern breeds. In color they are usually dark. 3. Ainerican Trotters, which are of American origin and are represented by a preponderance of blood in the native light horses of America. They are usually dark in color, but vary greatly in type. Quality and stamina are outstanding attributes, since they are descended from the Thoroug-hbred. 4. Morgans, a branch of the American Trot- ters. 5. American Saddle-Horses, which are found most numerous in Kentucky, Missouri and Tennessee. This breed possesses extreme style and quality and shows five gaits ; namely, walk, trot, canter, rack, running walk or fox trot or slow pace. The solid dark colors are preferred in this breed. II. Coach-Horses are larger than those of the former class. They range in weight from i , 1 50 to i ,450 pounds, and in height from 15.2 to 16 hands, the average weight being about 1,250 pounds, and height 15,3 hands. They are similar to Light Horses in skeletal structure, but are very smooth in conformation, showing thicker muscles and more symmetrical body curves. Their use is to draw fine carriages and carry fine harness, consequently style, action and quality are essential. Extreme higrh action at knee and 408 AGRICULTURE. hock, with rather a short but straight and elastic stride, is desirable. Speed is a secondary consideration. The head and tail should be carried high and every action should be that of >Jfi^ FIG. 152. — HACKNEY STALLION "SIR HUMPHREY" (98S9), 956. OwnedbyPabst Stock Farm, Oconomowoc, Wis. Winnerof ist Prize Hackney Stallion and Championship, and ist Prize for Stallion of any breed for getting harness horses — at the International Show, I^V' :'';,/ . '"'■'m^ ' ""^^ '- ^,>^- A ., .* • ' • .,■' FIG. 154. — PURE-BRED ABERDEEN ANGUS STEER "ANDY." Owned by Minnesota Agricultural College. Three years a winner at the International Live Stock Show. sought characteristic in modern beef-cattle. It is indicated by the compact form and the tend- ency to fatten at an early age. BREEDS OF BEEF-CATTLE. I. SJiortJiorns, a breeci which had its origin in northeast England, but owing to its great range of adaptability has become very widely scattered FARM ANIMALS. 415 and is particularly numerous in the United States, Canada, Australia and South America. They are one of the largest beef breeds. As the name indicates, they have short horns, flesh- colored muzzles and may be red, red and white, white, or roan in color. 2. Herefords are natives of Herefordshire, England. They have disseminated widely and, owing to their hardiness, have been used on the ranges in this and other countries in great num- bers. They have rather large horns, flesh-colored muzzles, and have for a color some shade of red with white faces or heads and white along the underline. 3. Aberdeen Angus Cattle are natives of north- east Scotland, They have been popular at a later date than the above-mentioned breeds, and owe their popularity to their excellent killing qualities. They are hornless, and black in color, with possibly a bit of white on the underside of the body. 4. Galloiuay Cattle have southwestern Scot- land for their home. They have not been dis- seminated as widely as the other breeds, but are improving in beef quality and increasing in popularity. They are hornless cattle, black in color, with some white on the underside of the body. They differ from the Aberdeen Angus in not being as thick-fleshed, and in having a longer coat of hair, which is wavy. 416 AGRICULTURE. 5. Sussex Cattle are natives of Sussex, Eng- land. They are solid red in color. 6. West Highland Cattle are natives of the uplands of Western Scotland. They vary in color from yellow to red, black and brindle. II. Dairy-Cattle have come to be veritable milk-producing machines. In milking condition they show little superfluous flesh and a very angular form. They should develop the triple-wedge conformation. By this is meant that they should widen from the withers to the shoulder joints, from the withers backward and downward, and from chest to abdomen, as viewed laterally. Quality is paramount in dairy-cattle, and is shown by fine skin, hair, bone and symmetrical development. Active, alert, energetic, yet tractable disposition, showing great nervous energy, with a propensity to utilize food for dairy production, constitutes dairy temperament. It is indicated by clear, in- telligent eyes, energetic yet perfectly controlled actions, and lack of superfluous flesh. Spinal processes which are prominent and wide-spaced indicate nerve force. Constitution is indicated by depth and width of chest, medium-size, and a healthy condition. The factors indicating capacity are medium-size muzzle, deep and broad barrel, and good appetite. The udder, which is a very important consideration, should be broad and capacious, attached well up behind and well FARM ANIMALS. 417 forward on the abdomen. Teats should be of medium size and squarely placed. The struc- tural formation of the udder should be glandular, 1 1 <' !' I A 4. J? IIIHI^K.^^1 t|f^y 78 Nitrogen 31,48, 109 available 87 compounds of 86 effect of 80 exhaustion from the soil . . 109 in plants 79 how obtained 81 Nutritive ratio 138 wide and narrow .... 139 Nymphs 290, 297 Ocean 17 Oleomargarine 168 Orange flower 263 Osmosis 61 PAGE Owl 310 O.xygen 9, 79 Paris Green 300 Paths 367 Perpetuating species .... 271 Phosphate 48, 82 deposits of 90 of lime 89 Phosphorus 82 compounds of 89 function of 82 m plants 82 Pine tar 276 Pipette 178, 182 Planker " ^i Plant-lice 299, 323, 325 Plants, chemical effects ... 30 deposits of 33 food of ... 1 ... . 78 amount needed .... 94 from water 62, 79 mechanical effects .... 28 protecting the soil . 28, 30, 36, 37 repotting 224 Plowing 67, 73 Potash 48 Potassium 84, 91 compounds of 91 Potting plants 226 Poultry 431 Brahmas 432 Cochins 432 Langshans 432 Leghorns 431 Minorcas 431 Orpingtons 432 Rocks 432 Wyandottes 432 Prairie dog 34 Principles of feeding .... 131 profit in 131 Propagation of plants . . . 201 from buds 219 diagram of 220 Protein 1 16, 132 Pruning 271,286 at transplanting 279 effect of improper . . 274, 375 fall 278 INDEX. 449 PAGE Pruning, general principles of J/I hardy shrubs -85 large limbs J 74 root 284 to induce fruitfulness . . . 284 to prevent overbearing . . 285 shade-trees 282 spring 278 when to prune 277 wliy to prune 279 Quail 315 Quality 4i>2 Relation between root-system and leaf-system .... 273 Rivers 15 Rolling 71 Rose-slug 324 Rotation of crops 153 courses in i57 effect upon insects . . 157,299 effect upon soil 153 effect upon vi'eeds .... 156 Roughage 145 Sand 7. 8, 46 Scale insects 299, 319 Scheele's green 300 School grounds 349 Scion 233 Seed-bed, preparation of . . . 67 Seedlings, peach 231 isolation of 249 variation of 253 Seeds 201 age of 206 germination of 207 jjreservation of 207 purity 204 seed coat 201 selection of 246 stratification 202 testing 202 treatment of fine seeds . . 211 vitality 204 Selection 245 artificial 398 diagram of 267 natural 297 PAGE Sheep 421 Cheviot 425 Cotswold 426 Dorset 425 English Down 425 Leicester 426 Lincoln 426 Merino 424 Kambouillet 424 Tunis 425 Shrubs 349, 375, 378 Silage 147 Skim-milk 181 Snowslides 20 Soiling 146 crops 159 Soils, acidity 97 alkaline 98 alluvial 44 chemical analysis .... 85 classification and properties . 42 clayey 46, 49 collecting . 47 fertility 84 foothold for plants .... ^^ furnishes plant-food ... jy inoculation of iio moisture and preparation of . 57 physical properties .... 49 pores of 54 sandy 46, 49 sedentary 43 storehouse for water ... "n subsoil 43 temperature of 50 transported 44 Soy-bean 112, 125, 126 Stable compost 99 Starch in wood 84 Stock 2},}, Sparrow 310,312,315 Spider 307 Sugar maple 373 Sycamore 373 Temperament 403 Temperature, curve .... 50 regulated by soil .... 78 regulated by rains .... 62 Tent-caterpillar, American . . 324 450 INDEX. PAGE Tent-caterpillar, forest . . . 3j8 Test bottles 177, 179 Thoroughbreds 405 Till 44 Tillage, surface 70 Timber, trees grown for . j8i, j8j Toad 307 Tobacco 304 dust 304 Tobacco, tea 304 smudge 304 Tomato worm 299 Trees 351, 370, ^yz Trotters 407 Underground streams .... 16 Variation 212, 245 bud 265 causes of 214, 397 fixation of 216 induced by cross fertiliza'.ion 259 induced by light 256 induced by pruning .... 257 of animals 395 Varieties, new 250 PAGE \'egetation experiments ... 85 Vetch 110 inoculation of . . . 1 11, 112 Water 12, 25 assorting power 16 capillary 59 capillary rise of ... . 53, 71 chemical action of ... . 12 deposition by . . . 14, 15, 16, 18 disintegrating power . . 13, 25 frozen 18 ground 59 hygroscopic 60 mechanical action of . . . 13 percolation of ... 52, 65, 70 transporting power of . . . 14 Waves 17 Weeds 312 seed 314 Winds 6 work of 6, 7 Wolff-Lehmann I'"eeding Stand- ards 136 Wounds, treatment of ... 276 Wren 308 STANDARD BOOKS PUBLISHED BY ORANGE TUDD COMPANY NEW YORK CHICAGO 09-441 Lafayette Street Marquette Building TDOOKS setit to all parts of the ivorld for catalog price Discounts for large quantities on appli- catia . Correspondence ini'ited. Brief descriptive catalog free. Large illustrated catalog, six cents. Soils By Charles William Bl'rkett, Director Kansas Agri- cultural Experiment Station. The most complete and popular work of the kind ever published. As a rule, a book of this sort is dry and uninteresting, but in this case it reads like a novel. The author has put into it his individuality. The story of the properties of the soils, their improvement and manage- ment, as well as a discussion of the problems of crop growing and crop feeding, make this book equally valuable to the farmer, student and teacher. There are many illustrations of a practical character, each one suggesting some fundamental principle in soil manage- ment. 303 pages. 5J/2 X 8 inches. Cloth $1.25 Insects Injurious to Vegetables By Dr. F. H. Chittenden, of the United States Depart- ment of Agriculture. 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