Q.630.7 II 6sr no. 38 cop. 5 ^i^ OGLE COUNTY SOILS 3% .■^^ ifs'r'erjrnTo Se' if^ '^^^ "^'"'=*' '^ -^Ponsible for To renew call Telephone Center, 333 8400 '^^ Un.vers.fy. LI61— O-1096 ''■'•'-Sir/ n£jiijm UNIVERSITY OF ILLINOIS Agricultural Experiment Station SOIL REPORT NO. 38 OGLE COUNTY SOILS Bv R. S. SMITH, O, I. ELLIS, E. K. DeTURK, F. C. BAUER, AND L. H. SMITH UBBAiNA, ILLINOIS, SEPTEMBER, 1927 The Soil Survey of Illinois was organized under the general supervision of Professor Cyril G. Hopkins, with Professor Jeremiah G. Mosier directly in charge of soil classification and mapping. After working in association on this undertaking for eighteen years. Professor Hopkins died and Profes- sor Mosier followed two years later. The work of these two men enters so intimately into the whole project of the Illinois Soil Survey that it is im- possible to disassociate their names from the individual county reports. Therefore recognition is hereby accorded Professors Hopkins and Mosier for their contribution to the work resulting in this publication. STATE ADVISORY COMMITTEE ON SOIL INVESTIGATIONS 1926-1927 Ralph All6n, Delavan F. I. Marm, Gilman N. F. Goodwin, Palestine A. N. Abbott, Morrison G. F. TuUock, Eockford W. E. Riegel, Tolono RESEARCH AND TEACHING STAFF IN SOILS 1926-1927 , Herbert W. Munif ord, Director of the Experiment Station W. L. Birrlisou, Head of Agnmomv Department Soil Physics and Mapping R. S. Smith, Chief O. I. Ellis, Assistant Chief D. C. Wimer, Assistant Chief E. A. Norton, Associate M. B, Harland, Associate R. S. Staufifer, Associate D. C. Maxwell, Assistant M. R. Isaacson, Assistant Soil Fertility and Analysis E. E. DeTurk, Chief V. E. Spencer, Associate F. H. Crane, Associate J. C. Anderson, First Assistant li. H. Bray,. First Assistant E. G. Sieveking, First Assistant H. A. Lunt, First Assistant R. Cowart, Assistant M. P. Catherwood, Assistant F. M. Willliite, Assistant Soil Experiment Fieldg F. C. Bauer, Chief* H. J. Snider, Assistant Chief John Lajnb, Jr., Associate M. A. Hein, Associate C. J. Badger, Associate A. L. Lang, Associate A. U. Thor, First Assistant J. E. McKittrick, Assistant L. B. Miller, Assistant Soil Biology O. H. Sears, Assistant Chief F. M. Clark, Assistant W. R. Carroll, Assistant W. R. Paden, Assistant Soils Extension F. C. Bauer, Professor* C. M. Linsley, Associate Soil Survey Fuhlications L. H. Smith, Chief F. W. Gault, Scientific Assistant Nellie Boucher Smitli, Editorial Assistant ' Kngftged in Soils Extension as well as in Soil Kxperiment Field*. INTRODUCTORY NOTE It is a matter of common observation that soils vary tremendously in their productive power, dcpcndinc^ upon their physical condition, their chemical com- position, and their biological activities. For any comprehensive plan of soil improvement looking toward the permanent maintenance of our agricultural lands, a definite knowledge of the various existing kinds or types of soil is a first essential. It is the i)urpose of a soil survey to cla.ssify the various kinds of soil of a given area in sucli a manner as to permit definite characterization for description and for mapping. With the information that such a survey affords, every farmer or landowner of the surveyed area has at hand the basis for a rational system of improvement of his land. At the same time the Experiment Station is furnished an inventory of the soils of the state, upon which intelli- gently to base plans for those fundamental investigations so necessary for solving the problems of practical soil improvement. This county soil report is one of a series reporting the results of the soil survey which, when completed, will cover the state of Illinois. Each county report is intended to be as nearly complete in itself as it is practicable to make it, even at the expense of some repetition. There is presented in the form of an Appendix a general discussion of the important principles of soil fertility, in order to help the farmer and landowner to understand the significance of the data furnished by the soil survey and to make intelligent application of the same in the maintenance and improvement of the land. In many cases it will be of advantage to study the Appendix in advance of the soil report proper. Data from experiment fields representing the more extensive types of soil, and furnishing valuable information regarding effective practices in soil manage- ment, are embodied in the form of a Supplement. This Supplement should be referred to in connection with the descriptions of the respective soil types found in the body of the report. Wliile the authors must assume the responsibility for the presentation of this report, it should be understood that the material for the report represents the contribution of a considerable number of tlie present and former members of the Agronomy Department working in their respective lines of soil mapping, soil analysis, and experiment field investigation. In this connection special recognition is due the late Professor J. G. Hosier, under whose direction the soil survey of Ogle county was conducted, and Mr. K. W. Dickenson who, as leader of the field party, was in direct charge of tlie mapping. UWIVl. : jt ILLINO AT UR8ANA-CHAMPA1G CONTENTS OF SOIL REPORT No. 38 OGLE COUNTY SOILS PAGE LOCATION AND CLIMATE OF OGLE COUNTY 1 AGRICULTURAL PRODUCTION 1 SOIL FORMATION 2 Geological Aspects 2 Changes in the River Systems 3 Physiography and Drainage 4 Soil Development 4 Soil Groups 4 INVOICE OF THE ELEMENTS OF PLANT FOOD IN OGLE COUNTY SOILS 6 The Upper Sampling Stratum 7 The Middle and Lower Sampling Strata 10 DESCRIPTION OF SOIL TYPES 15 (a) Upland Prairie Soils 15 (b) Upland Timber Soils 18 (c) Terrace Soils 22 (d) Residual Soils 26 (e) Late Swamp and Bottom-Land Soils 27 APPENDIX EXPLANATIONS FOR INTERPRETING THE SOIL SURVEY 29 Classification of Soils 29 Soil Survey Methods 31 PRINCIPLES OF SOIL FERTILITY 32 Crop Requirements with Respect to Plant-Food Materials '. 33 Plant-Food Supply , 34 Liberation of Plant Food 35 Permanent Soil Improvement 36 SUPPLEMENT EXPERIMENT FIELD DATA 46 The Mt. Morris Field 47 The Dixon Field 54 The Vienna Field 55 The Oquawka Field 57 The Manito Field 59 OGLE COUNTY SOILS By R. S. smith, O. I. PILLIS, E. E. DeTURK, F. C. BAUER, and L. H. SMITH' LOCATION AND CLIMATE OF OGLE COUNTY Ogle county is situated in the northwestern part of Illinois, about 24 miles south of the Wisconsin state line. It comprizes about 754 square miles and is traversed almost centrally from northeast to southwest by Rock river. Most of the county is tillable with the exception of the rough and broken land along Rock river. Approximately 21/2 percent of the area of the county is so rough and broken that it should be left permanently in timber. The weather data collected at Dixon, Lee county, for the fourteen-year period from 1911 to 1924 are used to indicate the climatic conditions of this region. The greatest range in temperature for any one year was 122 degrees, in 1919. The highest temperature recorded was 104°, in 1921 ; the lowest, 24° below zero, in 1919. The average date of the last killing frost in spring for this period was May 5 ; the earliest in autumn, October 16. The average length of the growing season is therefore about 164 days. The average annual rainfall for this period was 32.28 inches. The rainfall by months was as follows : January, 1.17 inches ; February, 1.33 ; March, 2.79 ; April, 2.70 ; May, 3.50 ; June, 3.82 ; July, 3.29 ; August, 3.57 ; September, 3,83 ; October, 3.01 ; November, 1.69 ; December, 1.55. AGRICULTURAL PRODUCTION Ogle county is regarded as distinctly agricultural, with about 95 percent of the land tillable. The Census of 1920 reports 2,784 farms in the county, as compared with 2,962 in 1910 and 3,093 in 1900. The agriculture of the county includes grain farming, dairying, and live- stock farming. It may be classed as general farming, with great emphasis placed on dairying and livestock, including the production of beef cattle, hogs, and, to less extent, sheep. It will be noted in the following tables that the total value of all livestock, for 1919, as reported in the Fourteenth Census, was about 8 million dollars, and that the total value of all crops for this same year was 131/^ million dollars. It is interesting to note in this connection that very little grain is shipped out of the county, most of it being used for feeding either on the farm where it is grown or on neighboring farms. Dairying is the predominant type of farming on the rolling and broken land adjacent to Rock river. The following figures taken from the Fourteenth Census indicate the rela- tive importance of the various kinds of livestock for 1920, and of livestock products for 1919 : * B. S. Smith, in charge of soil survey mapping; O. I. Ellis, Assistant Chief in soil survey mapping ; E. E. DeTurk, in charge of soil analysis ; F. C. Bauer, in charge of experiment fields ; L. H. Smith, in charge of publications. 2 Soil Report No. 38 Ammals and Animal Products Number Value Horses 19,205 $1,723,621 Mules 423 47,912 Beef cattle 39,656 2,362,449 Dairy cattle -. . 23,898 1,772,073 Sheep 8,423 124,367 Swine 70,533 1,705,248 Poultry 325,240 338,140 Eggs and chickens 742,495 Dairy products 1,196,735 Wool 51,165 lbs. 28,037 The report gives the total value of livestock as about 1% million dollars. The principal field crops are corn, oats, wheat, barley, hay, and clover. According to the Census, the total value for all crops in 1919 was $13,585,000. The following figures give the acreage and yield of some of the more important crops for the year 1919 : Crops Acreage Production Yield per acre Corn 107,799 4.298,629 bu. 39.8 bu. Oats 91,478 3,016,268 bu. 32.8 bu. Wheat 26,461 433,121 bu. 16.3 bu. Barley 11,854 293,959 bu. 24.7 bu. Rye 4,608 67,455 bu. 15.0 bu. Timothy 10,290 12,425 tons 1.20 tons Timothy and clover 31,428 44,299 tons 1.09 tons Clover 6,271 9,723 tons 1.55 tons Silage crops 10,101 76,514 tons 7.56 tons Corn for forage 12,387 31,361 tons 2.53 tons Figures furnished by the U. S. Department of Agriculture give the follow- ing acre-yields for the ten-year period 1911-1920 : corn, 36.2 bushels ; oats, 36.5 bushels; tame hay, 1.41 tons; winter wheat, 17.5 bushels. The fruit industry is not developed in Ogle county. Very little fruit is grown aside from small plantings for home use. SOIL FORMATION GEOLOGICAL ASPECTS One of the most important periods in the geological history of the county, from the standpoint of soil formation, was the Glacial period, during which and immediately following, the material that later formed the mineral portion of the soils was being deposited. During the Glacial period, great ice sheets moved southward from the centers of accumulation in Labrador, in the Hudson Bay region, and in the northern Rocky mountains. At least six great ice movements took place, each of which covered a part of northern United States, altho the same parts were not covered during each advance. The glaciations of northwestern Illinois, including the area occupied by Ogle county, have been a matter of uncertainty ever since the first classification of the drift sheets of this region. As explained on page 30, the system of number- ing the soil types is based largely upon the glaciations as outlined on the glacial map prepared many years ago by Leverett. This map shows Ogle county as being covered mainly by the lowan and Pre-Iowan glaciations but in the light of more recent evidence, the most of the county is now considered as belonging to Ogle County 3 the lUinoisan. It may be said, however, that so far as the identity of the soil types are concerned, the matter is not important. The eastern end of tlie county was probably invaded by a lobe of the early Wisconsin glaciation and the south- eastern corner of the county is occupied by Wisconsin moraines. The drift averages about 4 feet in depth on the upland, ranges from 150 to 400 feet deep in the preglacial valleys, and is about 100 feet deep on the Wis- consin moraine in the southeastern corner of the county. The loess or loess-like silt which constitutes the surface material varies from about 20 inches in depth in the eastern part of the county to 6 or 7 feet in depth in the western part. The shallow blanket of loess and drift explains the frequent occurrence of rock out- crop and stony soil along Rock i-iver and its tributaries, where the rolling topog- raphy has allowed the removal of the soil material by erosion. CHANGES IN THE RIVER SYSTEMS The drainage system of Ogle county has a complicated history. The pre- glacial Rock river flowed south from its present junction point with Kishwaukee river thru the eastern end of Ogle county. It cut a valley 3 to 5 miles wide thru most of its course and its depth below the present surface averages about 400 feet. The minor streams also have changed their courses and in some instances reversed their direction of flow. The gravel and sand ridges, known as eskers, also indicate major changes in the drainage channels of the county. Three of these eskers occur in Ogle county, known as the Adeline, Hazelhurst, and Stillman eskers. R7E i lOWAN GLACIATION PRE-IOWAN GLACIATION EARLY WISCONSIN MORAINES ^n>n\>^ terrace and SWAMP Fig. 1 — Drainage Map op Ogle County Showing Stream Courses, Terraces and Swamp Lands, and Glaciations (Glaciations based on Leverett map) 4 Soil Report No. 38 PHYSIOGRAPHY AND DRAINAGE The topography of Ogle county varies from flat to rolling, with rough and broken areas along Rock river and the others streams of the county. The flat topography is found in the terraces, while the undulating to rolling prevails in the upland prairie. Rock river is the main drainage channel of the county and most of the minor streams flow into this river within the boundaries of the county. The accom- panying drainage map shows the drainage of the county in detail. The altitude of Ogle county varies from about 700 to 931 feet. The follow- ing figures give the altitudes for a f eAv points in the county : Creston, 903 feet ; Rochelle, 795; Oregon, 702; Forreston, 931; Byron, 726. The altitude of Bloomington moraine in the southeastern part of the county varies from about 850 to 910 feet. SOIL DEVELOPMENT During the time which has elapsed since the last ice invasion, weathering and other processes have been active, resulting in the formation of the soils of the county as we know them today. When first deposited the general composition of any soil material, particularly loess, is rather uniform but with the passing of time various physical, chemical, and biological agencies of weathering form soil out of the parent material by some or all of the following processes : the leach- ing of certain elements, the accumulation of others; the chemical reduction of certain compounds, the oxidation of others; the translocation of the finer soil particles, and the arrangement of them into zones, or "horizons"; the accumu- lation of organic matter from the growth and decay of vegetable material. One of the very pronounced characteristics observed in most soils is that they are composed of more or less distinct strata, called horizons. As explained somewhat more fully in the Appendix, these horizons are named, from the surface down: A, the layer of extraction ; B, the layer of concentration or accumulation ; and C, less-altered material, or the layer in which weathering has had less effect. The development of horizons in a soil is an indication of its age. Since the upland prairie of this region has been occupied, probably con- tinuously, by grass vegetation, relatively large amounts of organic matter have accumulated, resulting in the formation of productive dark-colored soils. The areas adjacent to streams, which have been occupied by timber, are light-colored because of the relative deficiency of the surface soil in organic matter. The bottom-land soils are made up, for the most part, of alluvial material brought down from the uplands and deposited by the streams. These soils are to be re- garded as relatively young or immature and therefore have not developed horizons as have the mature soils of the upland. SOIL GROUPS The soils of Ogle county are divided into five groups, as follows: (a) Upland Prairie Soils, or dark-colored soils, usually rich in organic matter. Ogle County (b) Upland Timber Soils, or light-colored upland soils, usually relatively poor in organic matter. (c) Terrace Soils, including bench lands and second bottoms, formed by de- posits from flooded streams overloaded with sediment. (d) Swamp and Bottom Lands, including flood plains along streams and some poorly drained muck and peat areas. (e) Residual Soils, including Rock Outcrop and Stony Loam areas and soils formed in place thru weathering of rocks. Table 1 gives the area of each soil type in Ogle county and its percentage of the total area. It will be observed that 57.42 percent of the county consists of upland prairie, 20.50 percent of upland timber, 11.89 percent of terrace soils, 8.56 percent of swamp and bottom-land soils, and .95 percent of residual soils. The accompanying map, appearing in three sections, shows the location and boundry lines of the various types. For explanation concerning the classification of soils and interpretation of the maps and tables, the reader is referred to the first part of the Appendix to ■ this report. Table 1. — Soil Types of Ogle County, Illinois Soil type No. Name of type Area in square miles Area in acres Percent of total area (a) Upland Prairie Soils (600, 700, 900) 6261 7261- Brown Silt Loam 384.24 1.38 42.21 1.64 .10 .04 2.11 1.58 245 914 883 27 014 1 050 64 25 1 350 1 Oil 50.91 926J 626.51 726.5/ 760 Brown Silt Loam On Limestone .18 Brown Sandy Loam 5.59 660.5 760.5 Brown Sandy Loam On Limestone Brown Sandy Loam On Sandstone .22 .02 6281 728/ 781 Brown-Gray Silt Loam On Tight Clay Dune Sand ". .01 .28 6901 790/ Gravelly Loam .21 433.30 277 311 57.42 (b) Upland Timber Soils (600, 700, 900) 6341 734^ 9341 635\ 735/ 634.5 734.5 635.5 735.5/ 6641 764/ 665 \ 765/ 664.5 764.5 Yellow-Gray Silt Loam Yellow Silt Loam Yellow-Gray Silt Loam On Limestone . . . . Yellow Silt Loam On Limestone Yellow-Gray Sandy Loam Yellow Sandy Loam Yellow-Gray Sandy Loam On Limestone . . Yellow-Gray Sandy Loam On Sandstone . . 118.46 154.76 75 814 17.39 11 130 .81 518 .89 570 14.77 9 453 1.72 1 101 .09 .63 58 403 99 047 15.70 2.30 .11 .12 1.95 .22 .02 .08 20.50 Soil Report No. 38 Table 1.— Soil Types of Ogle County, Illinois — Concluded Soil type No. Name of type Percent of total area (c) Terrace Soils (1500) 1527 Brown Silt Loam Over Gravel 51.70 16. n 7.32 1.81 .25 8.69 2.19 .46 1.07 .05 .05 33 088 10 310 4 685 1 158 160 5 562 1 402 294 685 32 32 6.85 1525 Black Silt Loam 2.13 1566 1560.4 1561 Brown Sandy Loam Over Gravel Brown Sandy Loam On Gravel Black Sandy Loam .97 .24 .04 1536 1567 1564.4 1581 Yellow-Gray Silt Loam Over Gravel Yellow-Gray Sandy Loam Over Gravel .... Yellow-Gray Sandy Loam On Gravel Dune Sand 1.15 .29 .06 .14 1528 1568 Brown-Gray Silt Loam On Tight Clay Brown-Gray Sandy Loam On Tight Clay . . .01 .01 89.70 57 408 11.89 (d) Residual Soils (000) 083 Sand 2.92 3.62 .36 .31 .08 1 869 2 317 230 198 51 .38 098 098 099 099 Stony Loam — Limestone Stony Loam— Sandstone Limestone Outcrop Sandstone Outcrop .47 .05 .04 .01 7.29 4 665 .95 (e) Late Swamp and Bottom-L and Soils (1400) 1450 Black Mixed Loam 21.06 43.08 .38 13 479 27 571 243 2.80 1454 Mixed Loam 5.71 1401 Deep Peat .05 64.52 41 293 8.56 (f) Miscellaneous Water Gravel Pit 4.82 .18 .07 3 085 115 45 .64 .03 Rock Quarry .01 5.07 3 245 .68 Total 754.64 482 969 100.00 INVOICE OF THE ELEMENTS OF PLANT FOOD IN OGLE COUNTY SOILS In order to obtain a knowledge of its chemical composition, each soil type is sampled in the manner described below and subjected to chemical analysis for its important plant-food elements. For this purpose samples are taken usually in sets of three to represent different strata in the top 40 inches of soil ; namely, an upper stratum (0 to 673 inches), a middle stratum (6% to 20 inches), and a lower stratum (20 to 40 inches). These sampling strata correspond approxi- mately in the common kinds of soil to 2 million pounds per acre of dry soil in the upper stratum, and to two times and three times this quantity in the middle and lower strata, respectively. This, of course, is a purely arbitrary division of Ogle County 7 the soil section, very useful in arriving at a knowledge of the quantity and dis- tribution of the elements of plant food in the soil, but it should be borne in mind that these strata seldom coincide with the natural strata as they actually exist in the soil and which are referred to in describing the soil types as horizons A, B, and C. By this system of sampling we have represented separately three zones for plant feeding. The upper, or surface layer, includes at least as much soil as is ordinarily turned with the plow, and this is the part with which the farm manure, limestone, phosphate, or other fertilizing materials are incorporated. The chemical analysis of a soil, obtained by the methods here employed, gives the invoice of the total stock of the several plant-food materials actually present in the soil strata sampled and analyzed. It should be understood, how- ever, that the rate of liberation from their insoluble forms, a matter of at least equal importance, is governed by many factors, and is therefore not necessarily proportional to the total amount!^ present. For convenience in making application of the chemical analyses, the results as presented here have been translated from the percentage basis and are given in the accompanying tables in terms of pounds per acre. In doing this the assumption is made that for ordinary types a stratum of dry soil of the area of an acre and 6% inches thick weighs 2 million pounds. It is understood, of course, that this value is only an approximation, but it is believed that with this under- standing it will suffice for the purpose intended. It is, of course, a simple matter to convert these figures back to the percentage basis in case one desires to consider the information in that form. With respect to the presence of limestone and acidity in different strata, no attempt is made to include in the tabulated results figures purporting to repre- sent their averages for the respective types, because of the extreme variations frequently found within a given soil type. In examining each soil type in the field, however, numerous qualitative tests are made which furnish general in- formation regarding the soil reaction, and in the discussions of the individual soil types which follow, recommendations based upon these tests are given con- cerning the lime requirement of the respective types. Such recommendations cannot be made specific in all cases because local variations exist, and because the lime requirement may change from time to time, especially under cropping and soil treatment. It is often desirable, therefore, to determine the lime require- ment for a given field and in this connection the reader is referred to the section in the Appendix dealing with the application of limestone (page 36). THE UPPER SAMPLING STRATUM In Table 2 are reported the amounts of organic carbon, nitrogen, phosphorus, sulfur, potassium, magnesium, and calcium in 2 million pounds of the surface soil of each type in Ogle county. In connection with this table attention is called to the variation among the soil types with respect to their content of the different plant-food elements. It will be seen from the analyses that a variation in the organic-carbon content of the different soils is accompanied by a parallel variation in the nitrogen content. The organic-carbon content, which serves as a measure of the total organic 8 Soil Report No. 38 matter present, is usually 10 to 12 times that of the total nitrogen. This re- lationship is explained by the well-established facts that all soil organic matter contains nitrogen, and that most of the soil nitrogen (usually 98 percent or more) is present in a state of organic combination. This close relationship is also main- tained in the middle and lower sampling strata. The range in content of organic matter and nitrogen is very wide. The upland prairie soils are, for the most part, relatively high in these constituents. The upland timber soils are generally fairly low, with essentially no overlapping of organic matter in the two groups of soil types. The upland timber soils range from 19,660 pounds of organic carbon an acre in Yellow Silt Loam up to 30,410 pounds in Yellow-Gray Silt Loam, with an average of 24,460 pounds. The upland prairie soils, ranging from 30,500 to 49,380 pounds, average 41,330 pounds. One type, Dune Sand, is omitted from the average for upland prairie soils as given above, for, as is usually the case with very sandy soils, it is very deficient in organic matter and nitrogen, the organic carbon amounting to only 15,640 pounds an acre in the surface stratum. "While most soils should receive regular additions of organic materials in the form of green or animal manures and crop residues, in order to maintain an adequate supply of organic matter in actively decomposing condition, the fre- quent use of such materials is particularly necessary in the management of Dune Sand and similar types. The porous, open character of these soils permits the rapid oxidation of organic matter, so that it disappears from such soil much more rapidly than from the heavier types. Dune Sand is, in fact, but little more than the skeleton of a soil and cannot readily be brought up to, and maintained in, a state of productiveness without first incorporating active organic materials in it, and continuing with frequent subsequent additions. The soil is usually acid and hence limestone and legume green manures constitute the first and most important steps in converting it into a productive soil. Black Silt Loam con- tains the largest amount of organic carbon of any soil in the county, except Deep Peat, which is made up largely of organic matter. The organic carbon of Black Silt Loam amounts to 113,570 pounds an acre, with a corresponding nitrogen content of 12,990 pounds. While such soils as this will withstand more abuse by the practice of continuous cropping and are not so greatly in need of additions of organic materials as are soils containing only 20,000 to 30,000 pounds of organic carbon, yet the use of manure and the systematic growing of legumes for pasture and for plowing down serve to renew the active organic material in the soil in a way which is reflected in increases of crop yields. Other elements are not so closely associated with each other as organic matter and nitrogen. There is some degree of correlation, however, between sulfur, another element used by growing plants, and organic carbon. This is because a considerable tho varying proportion of the sulfur in the soil exists in the organic form, that is, as a constituent of the organic matter. Most of the Ogle county soils are fairly well supplied with sulfur. It ranges, in the surface soil, from a minimum of 260 pounds an acre in Dune Sand up to 3,550 pounds in Deep Peat. Excluding Deep Peat, the sulfur content of Ogle county soils amounts to one-half to two-thirds that of phosphorus. The sulfur available for crops is Ogle County 9 affected not only by the soil supply, but also by that brought down from the atmosphere by rain. Sulfur dioxid escapes into the air in the gaseous products from the burning of all kinds of fuel, particularly coal. The gaseous sulfur dioxid is soluble in water and consequently it is dissolved out of the air by rain and brought to the earth. In regions of large coal consumption the amount of sulfur thus added to the soil is relatively large. At Urbana, during the eight- year period from 1917 to 1924 there was added to the soil by the rainfall 3.5 pounds of sulfur an acre a month as an average. Similar observations have been made in other localities for shorter periods. At Spring Valley, in Bureau county, the rainfall during six summer months in 1921 brought down 34.5 pounds of sulfur an acre, or an average monthly precipitation of 5.75 pounds. The maxi- mum for a single month was 8.77 pounds, in June. At Toledo, Cumberland county, from April to November 1922, the average precipitation was 3 pounds an acre a month. The precipitation at the various points in the state in a single month has varied from a minimum of .74 pound to 10.22 pounds an acre. These figures afford some idea of the amounts of sulfur added by rain and also of the wide variation in these amounts under different conditions. On the whole, these facts would indicate that the sulfur added from the atmosphere supplements that contained in the soil, so that there can be no extensive need for sulfur fertilizers in Ogle county. In order to determine definitely the response of crops to applications of sulfur fertilizers, experiments with gypsum have been started at five experimental fields, namely, Raleigh, Toledo, Carthage, Hartsburg, and Dixon. With regard to phosphorus, the upland timber soils as a group are found to be relatively low. One type, Black Silt Loam, is outstanding in its phosphorus content. This type in Ogle county is found in the terrace area, and the surface soil contains 2,380 pounds of phosphorus in an acre. This soil type not only exhibits an unusually high phosphorus content, but is high in organic matter, nitrogen, calcium, magnesium, and sulfur as well. This type, however, occupies only 16.11 square miles, or 2.13 percent of the area of the county. Potassium is deficient in Deep Peat, as is usually the case with this soil type, the total amount in the upper 6% inches of soil being only 4,290 pounds an acre. The sandy types in Ogle county are for the most part only slightly lower in potassium content than is the case with soils of finer texture. The Residual Sand areas, however, are particularly poor, not only in potassium but in all the other mineral elements. The potassium content of the samples obtained was only 3,060 pounds an acre, or about one-tenth the amount ordinarily found in the mineral soils. Sandy soils carry a considerable proportion of their potassium content in the coarse sand grains. The relatively small total surface exposed in the case of the coarse particles greatly lowers the solubility and availa- bility of the potassium in sand soils. This is partly offset, however, by the greater depth of the feeding zone for crop roots in sandy soils as compared with the heavier types. The other types are normal in content of potassium. The variation in the calcium and magnesium content in the soils of this county is wide. Nearly all the sand and sandy loam types are markedly low in both calcium and magnesium, containing, generally, less than 4,000 pounds of 10 Soil Report No. 38 magnesium in the surface 6% inches, and somewhat larger amounts of calcium. The soils of finer texture are fairly well supplied with both of these elements. THE MIDDLE AND LOWER SAMPLING STRATA In Tables 3 and 4 are recorded the amounts of the plant-food elements in the middle and lower sampling strata. In comparing these strata with the upper stratum or with each other, it is necessary to bear in mind that the data as given for the middle and lower sampling strata are on the basis of 4 million and 6 million pounds of soil, and should therefore be divided by two and three respec- tively before comparing them Avith each other or with the data for the upper stratum, which is on a basis of 2 million pounds. With this in mind it will be noted in comparing the three strata with each other that some of the elements exhibit no consistent change in amount, either upward or downward, with increasing depth. This is true particularly of potas- sium. Others exhibit more or less marked variation in amount at the different levels. Furthermore, these variations as a rule, go in certain general directions, and by a careful study of them it is frequently possible to obtain clues as to the age or stage of maturity of the various soils and the nature of the processes going on in soil formation. With the exception of Deep Peat it will be observed that all the soil types diminish rather rapidly in organic matter and nitrogen with increasing depth, and that this diminution is quite noticeable even in the middle stratum. The sulfur content decreases with increasing depth in nearly all cases. This is to be expected since a portion of the sulfur exists in combination with the soil organic matter which is more abundant in the upper strata, and also because inorganic forms of sulfur are not tenaciously retained by the soil against the leaching action of ground water. Phosphorus, on the other hand, is not removed from the soil by leaching. It is converted by growing plants into organic forms and tends to accumulate in the surface soil in these forms in plant residues at the expense of the underlying strata. Evidently it is the second stratum (6% to 20 inches) which furnishes most of the phosphorus thus moved upward. Consequently, in nearly all the soil types in Ogle county the surface soil contains a larger pro- portionate amount of phosphorus than the middle stratum, and in the majority of cases more than the lower stratum. Two important basic elements, calcium and magnesium, have undergone some shifting in the different levels as exhibited by analyses of upland types. The content of calcium, on the whole, is much higher than that of magnesium in the surface soil, indicating a more abundant supply of calcium in the soil-forming materials. The calcium content remains the same or diminishes in the middle stratum as compared with the upper. This is accompanied by an increase in the magnesium content in both the middle and lower strata. These two elements are unequally removed from the soil by leaching, the calcium being dissolved and carried downward to a greater extent than magnesium. As they are carried downward in solution, magnesium is more readily reabsorbed by the soil mass than calcium, thus forcing more of the latter element out into the solution to be carried farther down. Consequently, while magnesium tends to accumulate in Ogle County 11 Table 2. — Plant-Food Elements in the Soils of Ogle County, Illinois Upper Sampling Stratum: About to 6% Inches Average pounds per acre in 2 million pounds of dry soil Soil type No. Soil type Total Total Total Total Total Total organic nitro- phos- sulfur potas- magne- carbon gen phorus sium sium Total calcium Upland Prairie Soils (600, 700, 900) 6261 726^ Brown Silt Loam 49 210 5 000 1 120 840 33 060 7 080 9 830 926J 726.5 Brown Silt Loam On Rock 43 520 5 100 1 100 860 31 460 9 080 11 180 760 Brown Sandy Loam 30 500 2 580 860 600 29 910 3 690 7 000 760.5 Brown Sandy Loam On Rock. . . 34 030 3 050 1 010 460 32 230 4 260 5 310 728 Brown-Gray Silt Loam On Tight Clay 49 380 4 040 660 640 23 400 6 240 10 880 681 Dune Sand 15 640 1 220 780 260 29 760 1 620 3 040 690 Gravelly Loam' Upland Timber Soils (600, 700) 734 735 734.5 635.5 764 765 764.5 Yellow-Gray Silt Loam Yellow Silt Loam Yellow-Gray Silt Loam On Lime stone Yellow Silt Loam On Limestone Yellow-Gray Sandy Loam . . . Y'ellow Sandy Loam Yellow-Gray Sandy Loam On Limestone 30 410 19 660 3 120 2 440 860 900 490 380 32 650 26 800 6 560 6 100 23 600 20 680 29 050 22 100 2 480 2 340 2 260 1 560 620 600 680 620 920 340 450 580 31 780 35 600 29 880 26 880 6 460 8 060 3 850 4 880 25 690 2 050 730 330 25 760 3 620 10 230 9 720 10 160 11 040 6 950 8 300 6 390 Terrace Soils (1500) 1527 1525 1566 1560.4 1561 1536 1567 1564.4 1528 Brown Silt Loam Over Gravel . Black Silt Loam Brown Sandy Loam Brown Sandy Loam On Gravel Black Sandy Loam Yellow-Gray Silt Loam Over. . . Gravel Yellow-Gray Sandy Loam Over Gravel Yellow-Gray Sandy Loam On Gravel Brown-Gray Silt Loam On Tight Clay 60 740 113 570 24 760 20 180 90 160 5 770 12 990 1 600 1 720 8 000 1 260 2 380 600 700 1 520 890 1 750 340 520 1 220 32 090 27 220 27 300 27 000 35 900 4 550 13 860 2 200 2 940 9 060 25 370 2 610 860 590 30 590 4 130 31 120 2 620 860 760 23 120 3 520 20 340 1 620 720 420 21 240 2 560 29 260 2 120 720 660 15 980 2 460 8 690 54 630 3 440 4 780 21 580 7 610 5 180 5 160 3 880 Residual Soils (000) 083 Residual Sand 28 340 1 680 620 520 3 060 1 620 1 140 098 Stony Loam^ Late Swamp and Bottom-Land Soils (1400) 1450 Black Mixed Loam^ 1454 Mixed Loam^ 1401 Deep Peat* 287 460 31 880 1 740 3 550 4 290 6 730 25 280 LIMESTONE and SOIL ACIDITY.— In connection with these tabulated data, it should be explained that the figures for limestone content and soil acidity are omitted not because of any lack of importance of these factors, but rather because of the peculiar difficulty of presenting in the form of numerical averages reliable information concerning the limestone requirement for a given soil type. A general statement, however, will be found concerning the lime requirement of the respective soil types in connection with the discussions which follow. 'Analyses not given because of uncertainty regarding the sample. ^Representative samples could not be taken because of the stony character of the soil. 'On account of the heterogeneous character of mixed loams, chemical analyses are not included for these types. ^Amounts reported are for 1 million pounds of Deep Peat. 12 Soil Report No. 38 Table 3. — Plant-Food Elements in the Soils of Ogle County, Illinois Middle Sampling Stratum: About Q% to 20 Inches Average pounds per acre in 4 million pounds of dry soil Soil type No. Soil type Total organic carbon Total nitro- gen Total phos- phorus Total sulfur Total potasi- Total magne- sium Total calcium Upland Prairie Soils (600, 700, 900) 626 726 926J 726.5 760 760.5 728 681 690 Brown Silt Loam. Brown Silt Loam On Rock Brown Sandy Loam Brown Sandy Loam On Rock. . . Brown-Gray Silt Loam On Tight Clay Dune Sand Gravelly Loam^ 51 320 56 920 44 690 50 900 38 520 26 480 5 000 5 720 4 390 4 300 3 400 1 640 1 820 2 000 1 590 1 960 1 360 2 120 1 270 1 040 970 900 920 240 66 740 63 200 64 200 64 660 49 760 65 480 17 670 20 120 8 550 7 620 15 920 2 320 20 800 25 960 15 190 10 900 19 760 5 560 Upland Timber Soils (600, 700) 734 735 734.5 635.5 764 765 764.5 Yellow-Gray Silt Loam Yellow Silt Loam Yellow-Gray Silt Loam On Limestone Yellow Silt Loam On Limestone Yellow-Gray Sandy Loam Yellow Sandy Loam Yellow-Gray Sandy Loam On Limestone 26 800 20 840 2 910 1 920 1 670 1 800 690 800 65 680 59 000 14 760 10 000 26 840 29 600 25 960 25 400 2 280 2 760 2 050 3 600 1 320 1 400 1 110 1 560 1 200 600 520 960 58 520 68 320 55 570 54 120 16 760 75 960 10 660 14 200 30 480 2 440 1 520 600 48 720 9 080 20 310 20 200 18 520 198 360 13 370 13 840 13 400 Terrace Soils (1500) 1527 1525 1566 1560.4 1561 1536 1567 1564.4 1528 Brown Silt Loam Over Gravel Black Silt Loam Brown Sandy Loam Brown Sandy Loam On Gravel Black Sandy Loam Yellow-Gray Silt Loam Over Gravel Yellow-Gray Sandy Loam Over Gravel Yellow-Gray Sandy Loam On Gravel Brown-Gray Silt Loam On Tight Clay 65 310 91 400 40 040 29 080 92 720 5 750 9 200 3 080 2 400 7 800 1 830 3 280 1 360 1 320 2 400 1 090 1 820 720 680 1 320 66 080 55 880 53 880 52 600 64 960 13 750 17 180 3 800 7 520 19 800 24 640 2 320 1 460 980 64 720 13 920 29 440 2 200 1 520 1 080 44 800 10 680 23 200 2 160 1 560 600 53 320 6 800 24 360 1 680 1 000 880 31 080 6 360 16 150 62 520 7 920 10 000 37 720 15 800 10 000 9 560 7 560 Residual Soils (000) 083 Residual Sand 34 440 2 000 1 040 840 5 600 2 360 3 280 098 Stony Loam* Late Swamp and Bottom-Land Soils (1400) 1450 Black Mixed Loam^ 1454 Mixed Loam^ 1401 Deep Peat' 572 466 54 980 1 760 2 200 10 380 8 120 40 620 LIMESTONE and SOIL ACIDITY.— See note in Table 2. 'Representative samples could not be taken because of the stony character of the soil. ^On account of the heterogeneous character of the mixed loams, chemical analyses are not reported for these types. 'Amounts reported are for 2 million pounds of Deep Peat. the middle and lower strata, the liberated calcium, which is thus carried farther down than magnesium may accumulate at still great depths, or may be washed away entirely. These movements of calcium and magnesium, as indicated by the analyses of the different strata, constitute one factor in estimating the rela- tive maturity of the various soil types. Ogle County 13 Table 4. — Plant-Food Elements in the Soils of Ogle County, Illinois Lower Sampling Stratum: About 20 to 40 Inches Average pounds per acre in 6 million pounds of dry soil Soil type No. Soil type Total organic carbon Total nitro- gen Total phos- phorus Total sulfur Total potasi- sium Total magne- Total calcium Upland Prairie Soils (600, 700, 900) 6261 726 [ 926J 726.5 Brown Silt. Loam 35 380 3 880 2 930 1 310 97 780 38 220 48 630 Brown Silt Loam On Rock' 760 760.5 Brown Sandy Loam Brown Sandy Loam On Rock' 35 840 3 940 2 260 960 94 960 48 020 84 200 728 Brown-Gray Silt Loam On Tight Clay . 33 840 28 740 3 000 780 3 000 1 800 540 780 74 460 95 220 35 880 5 520 41 880 681 Dune Sand 9 540 690 Gravelly Loam' Upland Timber Soils (600, 700) 734 735 Yellow-Gray Silt Loam Yellow Silt Loam 29 400 25 020 30 540 3 090 2 220 2 820 3 270 3 360 2 640 980 1 140 1 320 96 200 89 820 88 740 30 260 33 780 9 780 47 430 34 920 734.5 Yellow-Gray Silt Loam On Limestone 55 320 635.5 Yellow Silt Loam On Limestone' Yellow-Gray Sandy Loam Yellow Sandy Loam Yellow-Gray Sandy Loam On Limestone' 764 765 764.5 27 080 31 320 2 100 3 240 2 200 3 960 880 1 020 89 220 75 420 20 620 58 140 25 740 94 380 Terrace Soils (1500) 1527 1525 1566 1560.4 1561 1536 1567 1564.4 1528 Brown Silt Loam Over Gravel Black Silt Loam Brown Sandy Loam Brown Sandy Loam On Gravel Black Sandy Loam Yellow-Gray Silt Loam Over Gravel Yellow-Gray Sandy Loam Over Gravel Yellow-Gray Sandy Loam On Gravel Brown-Gray Silt Loam On Tight Clay 35 540 37 320 27 960 22 020 23 810 3 260 3 840 2 160 1 860 2 520 2 900 3 960 1 320 1 680 2 640 1 100 1 200 780 1 260 900 98 560 83 730 78 420 75 000 98 340 28 500 44 040 4 800 9 000 68 880 27 150 2 490 2 940 1 200 99 300 32 550 28 320 2 110 1 980 1 080 35 820 12 420 27 360 1 500 2 580 1 620 68 220 16 560 25 080 2 220 1 260 780 61 500 11 760 28 540 60 330 9 180 14 340 133 560 36 090 7 980 12 900 14 100 Residual Soils (000) 083 Residual Sand 098 Stony Loam' Late Swamp and Bottom-Land Soils (1400) 1450 Black Mixed Loam^ 1454 Mixed Loam^ . . . . 1401 Deep Peat' 904 140 95 250 2 280 2 490 is i20 14 ieo 72 696 LIMESTONE and SOIL ACIDITY.— See note in Table 2. 'Representative samples could not be taken because of the stony character of the soil. ^On account of the heterogeneous character of the mixed loams chemical analyses are not reported for these types. 'Amounts reported are for 3 million pounds of Deep Peat. It is frequently of interest to know the total supply of a plant-food element accessible to the growing crops. While it is not possible to obtain this informa- tion exactly, especially for the deeper-rooted crops, it seems probable that prac- tically all of the feeding range of the roots of most of our common field crops 14 Soil Report No. 38 is included in the upper 40 inches of soil. By adding together for a given soil type the corresponding figures in Tables 2, 3, and 4, the total amounts of the respective plant-food elements to a depth of 40 inches may be ascertained. Studying the figures in this manner the tables reveal that there is not only a wide diversity among the different soils with respect to a given plant-food element, but that there is also a great variation with respect to the relative abund- ance of the various elements within a given soil type as measured by crop re- quirements. For example, in one of the most extensive soil types in the county. Brown Silt Loam, Upland, we find that the total quantity of nitrogen in an acre to a depth of 40 inches amounts to 13,880 pounds. This is about the amount of nitrogen contained in the same number of bushels of corn. The amount of phosphorus, 5,870 pounds, contained in the same soil is equivalent to that con- tained in 34,500 bushels of corn, while in the same quantity of this soil there is present 197,580 pounds of potassium, the equivalent of that contained in approximately 1 million bushels of corn. In marked contrast to this soil, with respect to nitrogen, is the Yellow-Gray Silt Loam, an important upland timber soil type, which contains in the 40-inch stratum approximately 9,120 pounds per acre of nitrogen, an amount equal to that in 9,120 bushels of corn. The phosphorus content is nearly as high as in BroAvn Silt Loam, namely, 5,800 pounds in an acre, Avhich is equivalent to that contained in 34,100 bushels of corn. The potassium content of Yellow-Gray Silt Loam amounts to 194,530 pounds. With respect to calcium it is not feasible to make such comparisons in soil types which differ within themselves as to the presence or absence of native .calcium carbonate (limestone). In such soils the average calcium content cannot be taken as representative of the type. For example, one sample of Yellow-Gray Silt Loam is acid thruout the entire 40-inch depth, the carbonates having been leached to a greater depth than 40 inches. Another sample of the same type contains carbonates in the lower stratum (20 to 40 inches) and consequently is non-acid. The acid sample contains 26,940 pounds per acre of calcium in the lower stratum while the other has 95,640 pounds, or more than three times as much. These differences are thus much greater than the variations between averages of different soil types. The above statements are not hitended to imply that it is possible to predict how long it might be before a certain soil would become exhausted under a given system of cropping. Neither do the figures necessarily indicate the immediate procedure to be followed in the improvement of a soil, for other factors enter into consideration aside from merely the amount of plant-food elements present. Much depends upon the nature of the crops to be grown as to their utilization of plant-food materials, and much depends iipon the condition of the plant-food substances themselves, as to their availability. Finally, in planning the detailed procedure for the improvement of a soil, there enter for consideration all the economic factors involved in any fertilizer treatment. Such chemical data do, however, furnish an inventory of the total stocks of the plant-food elements that can possibly be drawn upon, and in this way contribute fundamental in- formation for the intelligent planning, in a broad way, of systems of soil man- agement for conserving and improving the fertility of the land. Ogle County 15 DESCRIPTION OF SOIL TYPES (a) UPLAND PRAIRIE SOILS The upland prairie soils of Ogle county occupy 433.30 square miles, or 57.46 percent of the area of the county. They are fairly well distributed over the county with the exception of the territory adjacent to Rock river, which is occupied by timber soils. The dark color of the prairie soils is due to the accumulation of organic matter, which is derived very largely from the fibrous roots of the prairie grasses. The network of grass roots was protected from rapid and complete decay thru the partial exclusion of oxygen by the covering of fine, moist soil and mat of vegetative material consisting of old grass stems and leaves. The stems and leaves were burned in part by prairie fires or disappeared in part by decay. Thus they added but little organic matter to the soil directly, but, being con- stantly renewed, they helped to cheek the decay of the fibrous roots. Brown Silt Loam (626, 726, 926) Brown Silt Loam is the most extensive of the upland types in Ogle county. It covers an area of 384.24 square miles, or just about one-half of the area of the county. This type shows some variation in the different parts of the county with reference to the depth of horizons, color, texture, and topography. Its topogra- phy varies from undulating to rolling. The southeastern corner of the county, which is morainal, and the north and west portions are rolling. The remainder of the Brown Silt Loam is undulating to slightly rolling in topography. Drainage in this type is well developed. The depth to the glacial till varies in the different parts of the county. The underlying material thruout the type is glacial drift, with the exception of the areas where no till was deposited or where it has been eroded away, in which eases the soil has developed directly on the bed rock. The thickness of the surface loess, or loess-like material, varies from about 20 inches to as much as 6 feet. These differences in depth and associated differences in soils are not shown on the soil map. Brown Silt Loam adjacent to Sandy Loam is more or less of a sandy texture. Practically all of the type is under cultivation. The A^ horizon, which is about 7 inches thick, is a light to medium brown silt loam, having an appreciable amount of sand present near the sandy areas. The Ag horizon, extending to a depth of about 18 inches, is friable in texture and varies from a light brown silt loam with a slight yellow cast to a yellowish brown silt loam. The yellowish shade occurs on the more rolling areas. The B horizon is about 20 inches in thickness and is a slightly compact yellow silt loam with slight joint mottling. Below a depth of 24 to 38 inches the C horizon occurs. This is a friable yellow silt loam, somewhat mottled in the joints and splotched with yellow and red iron concretions. The type shows the same character of profile on the areas where the till lies within 20 inches or so of the surface, with the exception that the surface, sub- surface, and subsoil horizons are not so thick as where the till is deeper. 16 Soil Report No. 38 Management. — For suggestions regarding the management of this soil, the reader is referred to the results of experiment fields at Mt. Morris and at Dixon, pages 47 and 54, which may be considered as fairly representative of most of the Brown Silt Loam as it occurs in Ogle county. It will be noted that manure has given excellent returns on these fields' and that the use of limestone has paid a fairly good profit. The use of rock phosphate has resulted in crop increases just about sufficient to pay for the application of one-half ton of this material per acre once in four years. The reader is referred to page 39 for a further discussion of the phosphate problem. Present knowledge regarding the management of this soil, while not com- plete, indicates clearly the need for fresh organic matter, and, on a considerable portion of the type, an application of limestone. The amount of limestone needed varies and should be determined for each field. The clovers, or other legumes, should be regularly grown to supply fresh organic matter and also nitrogen. At the same time this is being done, trials may well be made of the various phos- phates including rock phosphate, basic slag, steamed bone meal, and acid phos- phate. It should be borne in mind in making these trials that, of the grain crops, wheat responds best to phosphate. Brown Silt Loam On Limestone (626.5, 726.5) Brown Silt Loam On Limestone occurs in small scattering areas thruout most of the county, occupying a total of 1.38 square miles. This type is usually located on the slopes of the more rolling areas of prairie soil where the limestone occurs within 30 inches of the surface. Only a very general description of the soil horizons can be written because the depth to the rock varies from a few inches to about 30 inches. The Aj horizon, with an average depth of 6 inches, is a brown silt loam. The Ag horizon, extending to a depth of about 18 inches, is a light brown to a yellowish brown silt loam. The B horizon extends to the bed rock which occurs at variable depths as stated above. This horizon occurs in two parts. The upper part is a slightly compact yellow silt loam; the lower is a compact, red, residual clay from 2 to 4 inches in tliickness resting directly on the limestone. Management. — This type is suitable only for pasture because of its drouthy nature. It produces excellent bluegrass and, with the exception of the shallower portions, should grow good sweet clover. Brown Sandy Loam (760) Brown Sandy Loam occurs east of Rock river, in the regions of the glacial fills of the old preglacial stream valleys, and also adjacent to Rock river. The sandy texture of the soil is due to wind action which has blown the sand out of the bottoms upon the uplands. The topography of the type is undulating to rolling. The drainage is usually well developed, owing to the open subsoil. The A^ horizon, extending to a depth of about 8 inches, is a brown sandy loam. The Aj, horizon which extends to a depth of about 18 inches, is a light brown to yellowish brown sandy loam. The upper 8 or 9 inches of the B horizon Ogle County 17 varies from a friable, yellow sandy loam, splotched with gray, to a slightly com- pact, yellow clayey sand. The C horizon is a yellow, sandy, gravelly loam. It occurs at a depth of 25 to 35 inches. Management. — Brown Sandy Loam is somewhat acid, tho it varies in degree of acidity. It has a slight tendency to he drouthy in places where the soil is shallow, and in some areas considerable trouble is caused by its drifting with the wind. The general recommendations for the management of this type include the application of limestone at the proper rate, the growing and turning down of legumes, preferably sweet clover, and the use of early maturing crops on the drouthy areas. The proper rate of application of limestone can be determined by the County Farm Adviser or by securing the assistance of the Agricultural Experiment Station. Alfalfa will do well on this soil after sufficient limestone has been applied, particularly if it is preceded by sweet clover. Brown Sandy Loam On Limestone (660.5) Brown Sandy Loam On Limestone, which occupies only 1.64 square miles, or .22 percent of the area of the county, occurs in scattering areas along the east side of Rock river. Usuall.y, these areas are rather indefinite as to outline because of the irregularity in the contours of the limestone beds. Most of the areas have been left in permanent pasture, because the rock is too near the surface for cropping. The topography is slightly rolling, permitting good drainage. The limestone lies at depths varying from a few inches to 30 inches below the surface, the most common depth being 8 to 20 inches. The Aj horizon, varying from 4 to 7 inches in thickness, is a brown sandy loam. The Aj horizon is a light brown sandy loam. The B horizon, which varies from 4 to 6 inches in thickness, lies directly on the limestone and is either a com- pact, reddish yellow, gravelly, sandy clay, or a red clay. Management, — This type is better adapted to permanent pasture than to the general farm crops. Its occurrence, however, as small scattering areas in the Brown Sandy Loam makes it necessary to farm many of the areas in the same way that the latter type is farmed. General suggestions for the manage- ment of Brown Sandy Loam may be found on page 16. Brown Sandy Loam On Sandstone (760.5) Brown Sandy Loam On Sandstone, which occupies a total of only 64 acres, occurs south of Oregon. The topography of the region in which the small areas of this type occur is undulating to rolling. Drainage is well developed, owing to the slope and to the open nature of the soil. This type may be thought of as poor spots in Brown Sandy Loam. For this reason it usually is not practical to give it any special management. Brown-Gray Silt Loam On Tight Clay (628, 728) Only 25 acres of Brown-Gray Silt Loam On Tight Clay, Upland, occur in Ogle county. 18 Soil Report No. 38 The A^ horizon is a grayish brown silt loam. The A2 horizon is a gray silt loam, and the B horizon is a tough, plastic, compact, drab clay. Management. — The small area of this type in Ogle county makes its manage- ment of no general interest. Suggestions may be secured from the Agricultural Experiment Station by anyone interested. Dune Sand (781) Dune Sand, Upland, comprizes a total of 2.11 square miles in Ogle county. It occurs in the areas of sandy loams where the wind has had opportunity to rework the sand particles and has redeposited them in dune-like formations. Blowouts, as well as dunes, are common in the region. The topography of the type is billowy. The Aj horizon, which varies from to 3 inches in thickness, depending on the amount of organic matter that has accumulated, is a brownish yellow to yellow, loamy sand. There is no distinct horizon development below this shallow, brownish surface, the material below consisting of yellow sand. Management. — Dune Sand is somewhat acid and the correction of this con- dition by the use of limestone is the first step towards the profitable utilization of this type. The Oquawka experiment field is located on Dune Sand and very striking results have been secured there with limestone and manure and with limestone and sweet clover. The reader is referred to page 58, where the crop yields on this field are given. The information given by these figures is the best available for Dune Sand, either Terrace or Upland, as it occurs in Ogle county. Gravelly Loam (690, 790) Gravelly Loam occupies a total area of only a little more than II/2 square miles. It occurs in the localities where eskers, or gravelly ridges, have been built by subglacial streams or in crevices of the ice mass. Very little loessial material occurs on these gravel ridges. The three main areas of Gravelly Loam are the Adeline, HazeUiurst, and Stillman Valley eskers. They are of very little agricultural value aside from pasture. The gravels are used for road building and railroad fills. (b) UPLAND TIMBER SOILS The upland timber soils occur as irregular zones along streams and on or near somewhat steep morainal ridges. Their most noticeable characteristic is the yellowish gray color of the surface, due in part to its low organic-matter content. The deficiency in organic matter has been caused by the long-continued growth of forest trees. Two effects were produced by the forest trees: the shade from the trees prevented the growth of prairie grasses, the roots of which are mainly responsible for the large organic-matter content in prairie soils; and the trees themselves added very little organic matter to the soil, for the leaves and branches either decayed completely or were burned by forest fires. As a result, the organic-matter content of the upland timber soils is always less than that of the adjacent prairie land. Several generations of trees were necessary to pro- duce the present condition of the soil. Ogle County 19 The upland timber soils occupy 154.70 square miles, or practically one-fifth of the area of the county. Yellow-Gray Silt Loam (634, 734, 934) The total area of Yellow-Gray Silt Loam in Ogle county is 118.46 square miles, or 15.70 percent of the area of the county and approximately 75 percent of the total area of the timber soils. It occupies the portion of the light-colored or timber soil area of the county which has an undulating to slightly rolling topography. In the northwestern part of the county certain areas have been classified as Yellow-Gray Silt Loam in which the light color of the soil is the result of erosion rather than of forest growth. These areas altho not strictly of the type Yellow-Gray Silt Loam, are correlated with it because of their small total extent. The Aj horizon, which is about 6 inches in thickness, is a brownish yellow to a grayish yellow silt loam. The A^ horizon, extending to a depth of about 18 inches, is a yellow silt loam mottled with gray. The B horizon, extending to about 32 inches in depth, is a slightly mottled, slightly compact, yellow silt loam. The C horizon, below 32 inches, is a friable, strongly mottled, yellow silt loam splotched with brown and red iron concretions. Management. — Yellow-Gray Silt Loam is slightly acid and is low in nitrogen and organic matter. The application of about 2 tons of limestone an acre and the growing of sweet clover are recommended as effective treatments in rapidly increasing the productivity of this soil. The sweet clover can be used to advan- tage by pasturing it in the fall of the first year and ploAving it down for corn in the spring of the second year. If wheat is grown, it is suggested that a trial be made of one or more of the following carriers of phosphorus: acid phos- phate applied at the rate of about 300 pounds an acre, steamed bone meal at half the above rate, basic slag applied at the rate of about 200 pounds an acre, or rock phosphate applied at the rate of about 1,000 pounds an acre. There are no experiment field results exactly applicable to this soil type as it occurs in Ogle county, but the very striking increases in yield obtained with steamed bone meal as well as with rock phosphate, on a somewhat similar soil in Lake county, leads to the suggestion that some form of phosphate be given thoro trial. Yellow Silt Loam (635, 735) Yellow Silt Loam occurs in irregular areas as rough and broken land imme- diately adjacent to streams and on slopes at some distance from the streams. As mapped, it is the eroded portion of the timber soils from which much or all of the surface soil has been removed by washing, exposing a yellow subsoil. Yellow Silt Loam covers 17.39 square miles, or 2.30 percent of the area of the county. The exact character of this type varies greatly because of differences in vegetation and the amount of washing. The Ai horizon, which may extend to a depth of 3 or 4 inches, is usually a grayish yellow to a brownish yellow silt loam. Below this depth, a friable yellow silt loam may occur, which rests on a medium plastic, rather compact, yellow 20 Soil Report No. 38 silty clay loam. Till and limestone rock Vary in depth below the surface, de- pending on the amount of erosion that has taken place. Usually the depth to till or rock varies from 25 or 30 inches to 4 or 5 feet. A stratum of yellowish red, sandy clay loam, 4 to 8 inches in thickness, frequently occurs directly above the limestone. Management. — The timber has been cut off from practically all of the land included in this type. Certain areas of the type near Rock river have grown up in underbrush and scrub timber and are of no value as sources of timber and of little value as pasture. Other areas have been farmed with disastrous results because of erosion. The less steep slopes may be farmed successfully but special precautions must be taken to reduce erosion. The wisest course to follow with this land is to put the steepest slopes in timber and the less steep slopes in orchard or permanent pasture. .Results of some experiments on this type as it occurs in southern Illinois is given in the account of the Vienna field, found on page 55. Yellow-Gray Silt Loam On Lim^tone (634.5, 734.5) Yellow-Gray Silt Loam On Limestone occupies a total area of less than one square mile. It occurs as small areas thruout Yellow-Gray Silt Loam. The A^ horizon, which is about 5 or 6 inches in thickness, is a grayish yellow silt loam. The Ag horizon, extending to about 14 inches in depth, is a yellow silt loam mottled with gray. The B horizon, which is made up of two distinct strata, extends to the bed rock. The upper portion is a compact, slightly mottled, yellow silty clay loam. It rests on a layer of sticky, compact, reddish yellow to red residual clay about 3 or 4 inches in thickness. This red clay rests directly upon the limestone which lies 20 to 30 inches below the surface. Management. — Since this type is so intimately associated with Yellow-Gray Silt Loam, it must in most cases receive the same management as Yellow-Gray Silt Loam. The reader is referred to the discussion of the latter type on page 19. Yellow Silt Loam On Limestone (635.5, 735.5) Yellow Silt Loam On Limestone occupies the same topographic position as Yellow Silt Loam. It covers only .89 of a square mile and is usually found on the steepest slopes. The type is non-agricultural, owing to the nearness of the limestone to the surface and the steepness of its topography. The depth to limestone varies from a few inches to as much as 30 inches below the surface. The Ai horizon is usually about 2 or 3 inches in thickness and varies from a dark brown or brownish yellow to a grayish yellow silt loam. Below this depth a stratum of yellow silt loam occurs which is usually about 6 inches in thickness. As the underlying limestone is approached, the material becomes a plastic, sandy to gravelly, yellow clay loam, with a stratum of red, residual clay immediately on top of the limestone. Management.— "Thi^ type can be used in most cases only for timber or pasture. Ogle County 21 Yellow-Gray Sandy Loam (664, 764) Yellow-Gray Sandy Loam occurs near Rock river, where a considerable amount of sand has been blown from the bottom land and deposited on the upland by the winds. It occupies 34.77 square miles, or 1.95 percent of the area of the county. The topography of the type varies from undulating to rolling. Drainage is good because of the open sandy subsoil. The A^ horizon, which is about 5 inches in thickness, is a grayish yellow sandy loam. The A^ horizon, extending^ to a depth of about 15 inches, is a yellow sandy loam with slight joint mottling. The B horizon, in the upper portion, is a slightly compact, yellow, sandy silt loam. In the lower portion it is a yellow sand at about 24 or 25 inches. At about 32 inches a gravelly glacial till occurs, wMch may rest on limestone bed rock within 35 or 40 inches of the surface. Management. — A portion of this type remains in timber and some of it is in permanent pasture. Both the nitrogen and organic-matter contents of the soil are low and an application of about 2 tons of limestone an acre must be made before sweet clover or alfalfa can be grown. The open nature of the subsoil makes this type somewhat drouthy, and for that reason it is advisable to grow early maturing crops. Provision should be made in the cropping system for the regular addition of leguminous green manure to the soil. No mineral fertilizer treatment is advised for this type except on a small trial basis.' Yellow Sandy Loam (665, 765) Yellow Sandy Loam occurs as eroded areas in the__same region as Yellow- Gray Sandy Loam. It is also found on some of the steep slopes of the Residual Sand areas. It occupies a total of only 1.72 square miles, and only areas of small acreage are to be found, most of which are near Rock river. This soil to a depth of 2 to 5 inches is a brownish yellow to yellow sandy loam. No distinct Ag, B, or C horizons are distinguishable because of the fact that this soil is immature, owing to rapid erosion. For a depth of 15 to 18 inches it is usually a yellow sandy loam, and below this depth a yellow to reddish yellow, sandy clay loam occurs. The reddish color usually occurs in a stratum 6 to 8 inches thick, which lies directly above the sandstone or limestone. Management. — Yellow Sandy Loam is, for the most part, kept in pasture and timber and this practice should be continued. Yellow-Gray Sandy Loam On Limestone (664.5) Yellow-Gray Sandy Loam On Limestone occurs in small, scattering areas thruout the limestone region along Rock river. It covers a total of only .09 of a square mile. This type is very similar to Yellow-Gray Silt Loam with the ex- ception that the underlying limestone occurs at a depth of 12 to 28 or 30 inches below the surface. It is of very little importance and should be handled in the same way as Yellow-Gray Sandy Loam (see management discussion above). 22 Soil Report No. 38 Yellow-Gray Sandy Loam On Sandstone (764.5) Yellow-Gray Sandy Loam On Sandstone occurs in scattering areas in the sandstone region. It occupies a total of only .63 of a square mile. Most of the type is utilized for pasture land because the sandstone is too near the surface for good farm land. It is of even less value than Yellow-Gray Sandy Loam On Limestone and no effort should be made to put it in cultivated crops. (c) TERRACE SOILS Nearly all of the terrace soils are located in the eastern part of the county along the course occupied by the preglacial Rock river. In addition to this large terrace Rock river has constructed small sand and gravel terraces along its present course, and some small terraces are found along the small streams. These terraces were formed by streams overloaded with sediment during flood periods. Later when the streams diminished in volume, these former flood plains were no longer overflowed and became terraces. At the same time new flood plains at lower levels were formed. Brown Silt Loam Over Gravel (1527) Nearly all the areas of Brown Silt Loam Over Gravel are found in the eastern part of the county, in the preglacial Rock river terrace. Some small areas occur along Rock river and its tributaries. The type occupies 51.7 square miles, or 6.85 percent of the area of the county. In topography it varies from flat to undu- lating. Drainage has, for the most part, been well established thru the construc- tion of dredges and lateral tiling. In the southern part of the .county near Rochelle the type is a heavier phase and needs better drainage than is at present provided. The A^ horizon, which is about 8 inches thick, is a brown to dark brown silt loaih. The Ag horizon, extending to a depth of about 18 inches, is a yellowish brown silt loam. The B horizon occurs as a stratum about 12 inches in thickness. It varies from a slightly plastic, fairly compact, silty clay to silt loam. It is usually drabbish gray in color. The C horizon occurs below 30 inches. It is a friable, mottled, yellow silt loam splotched with orange-red concretions. The depth to sand and gravel varies from 42 to 50 inches below the surface. Management. — This type varies in acidity and each field should be tested before applying limestone. The reader is referred to the discussion of Brown Silt Loam, Upland, page 15, for suggestions regarding the management of this terrace type. Black'^SiltjLoam (1525) ■ Black Silt Loam is second in extent of the terrace types, occupying 16.11 square miles. It is found in scattered areas thruout the preglacial Rock river terrace and occupies the low-lying, flat land. The transition from Brown Silt Loam to Black Silt Loam is very gradual. The Aj horizon, which is about 6 inches thick, varies from black silt loam to black silty clay loam, with a slight gray cast in areas which are alkaline. The Aj horizon, which extends to a depth of about 17 inches, is a plastic, black clay I Ogle County 23 loam. The B horizon in the upper 14 inches is a plastic, compact, drab clay loam, splotched with yellow and gray streaks. The lower part of the B horizon, ex- tending to about 40 inches in depth, varies from a plastic, drab to gray, silty clay loam. Below 40 inches it changes to a friable material which rests on a substratum of yellow to gray sand at a depth of about 48 inches. Management. — The drainage of the low-lying, flat land occupied by this type has been fairly well taken care of by dredge ditches and tile, altho portions of the type need additional drainage. Alkali is common thruout the type and occurs in harmful amounts in some places. Its bad effects may be counteracted by the use of about 100 pounds of a potash salt per acre. The organic-matter con- tent of this soil is high, but it should not be cropped continuously without the addition of fresh organic matter at regular intervals in the rotation. The prac- tice has become common of raising a crop of sweet corn on this land followed the same year by a crop of peas. This practice gives a high return, but if con- tinued on the same land year after year, it would not provide for returning sufficient organic matter to the soil. Brown Sandy Loam Over Gravel (1566) Brown Sandy Loam Over Gravel is found in scattered areas thruout the different terrace formations of the county ; most of it, however, occurs along Rock river, and Stillman and Kyte creeks. The topography of the type varies from undulating to rolling. Drainage is good because the type is underlain with sand and gravel. It occupies 7.32 square miles, or .97 percent of the area of the county. Practically all of the type is under cultivation, altho some of it in the vicinity of Daysville and Honey Creek is left in pasture because of the low organic-matter content and the high percent of sand. The Aj horizon, extending to about 8 inches in depth, is a medium to coarse- grained brown sandy loam. The A^' horizon, which extends to a depth of about 18 inches, is a yellowish brown to yellow sand. The B horizon, in the upper 6 or 7 inches, is a slightly plastic, somewhat compact, yellow, sandy clay loam, slightly mottled and splotched Avith brown iron concretions. Below 28 inches, it is a yellow sand, strongly splotched with red iron concretions. About 38 to 45 inches below the surface, the sand contains a considerable amount of small pebbles. Management. — As a general rule the drainage of the undulating phase is fair, but in the flat areas near Daysville, artificial drainage is necessary. Some difficulty is encountered in the case of open ditches which tend to fill up rapidly with sediment. This soil will respond well to good farming, including the applica- tion of limestone and the turning down of nitrogenous organic matter. It is a good alfalfa soil and produces good corn following sweet clover or alfalfa. Brown Sandy Loam On Gravel (1560.4) Brown Sandy Loam On Gravel occurs along the old preglacial Stillman creek in the vicinity of Stillman Valley and a few scattering areas along Rock river. It covers a total area of only 1.81 square miles. The topography is undu- lating and the drainage is well developed since there is plenty of fall to the 24 Soil Report No. 38 streams and the substratum is open. The nearness of the gravel to the surface has a detrimental effect upon growing crops during seasons of drouth. The A^ horizon, extending to a depth of 8 inches, is a medium to coarse- grained brown sandy loam. The Ag horizon, which extends to about 21 inches in depth, is a yellowish brown sand. Since the depth to the underlying gravel varies from 22 to 34 inches, depending on the contour of the gravel bed, the B horizon is variable in depth and texture. On an average it is 6 or 7 inches in thickness and is a slightly compact, yellow clayey sand, with some fine gravel, resting on gravelly sand, directly above the gravel deposits. Management. — The fact that the stratum of soil above the gravel is rather thin accounts for the drouthy nature of this type. Since the soil is low in nitrogen and organic matter, the growing of legumes is advised. With the tendency of the type to be slightly acid, an application of about 2 tons of limestone is ad- visable. Also, the use of early maturing crops is recommended because for such crops the period of greatest need of moisture is past before the driest part of the season approaches. Black Sandy Loam (1561) Black Sandy Loam is located in the terraces of Kishwaukee river in the northeast part of the county. It occupies only about 160 acres. It is flat in topography and has been fairly well drained of late years. It is slightly lower in elevation than the adjoining types. The A^ horizon, which is about 6 inches thick, is a black sandy loam, with some silty and clayey spots too small to show on the map. The A^ horizon, extending to a depth of about 17 inches, is a brov/n to black sandy loam. The B horizon in the upper 7 inches is a drab sandy loam, becoming a clayey sand at about 2-1 inches. Below this depth it is a slightly compact, sandy clay loam, drabbish yellow to yellow in color, which passes into a yellow sand at depths vary- ing from 36 to 45 inches below the surface. Management. — The improvement of the underdrainage is the first problem in the management of this type in order to lower the water table and remove the alkali which occurs in spots. These spots can be made productive by applying potassium salts at the rate of about 100 pounds an acre. Plowing down manure and straw also helps in overcoming the bad effects of the alkali. Legumes should have a regular place in the rotation as a source of nitrogen and readily de- composable organic matter, particularly for the non-alkali portions of the type. Yellow-Gray^Silt Loam Over Gravel (1536) Yellow-Gray Silt Loam Over Gravel occurs in scattered areas thruout the terraces, particularly along Rock river and its tributaries. The type occupies a total of 8.69 square miles. Its topography is undulating and the drainage is fairly well established, altho there are small depressions of a heavier soil, rather poorly drained, scattered thruout the areas. The Ai horizon, which is about 6 inches in thickness, is a friable brownish yellow or grayish yellow silt loam. The Ag horizon, extending to a depth of about 18 inches, is a friable, mottled, yellow silt loam. The B horizon in its upper Ogle County 25 18 inches is a plastic, compact, slightly mottled, yellow silty clay loam which changes to a plastic, compact, golden yellow silt loam at about 42 inches. This lower stratum rests on the gravel which is calcareous and well stratified. Management. — The management requirements of this type are the same as for Yellow-Gray Silt Loam, Upland (see page 19). Yellow-Gray Sandy Loam'OverjGravel (1567) Yellow-Gray Sandy Loam Over Gravel occurs in small areas thruout the terraces of Rock river and some of the preglacial stream formations. It occupies a total area of only 2.19 square miles. It is undulating in topography. Because of the closeness of the gravel beds to the surface, the type is well drained and yet at the same time it is not drouthy. The Aj^ horizon, which is about 7 inches thick, varies from a yellowish brown to a grayish yellow sandy loam. The Ag horizon, which extends to a depth of about 15 inches, is a slightly mottled, yellow sandy loam. The B horizon to a depth of about 22 inches is a fairly compact, yellow sandy clay loam. Below 22 inches it is a yellow sand with sand and gravel beds occurring at about 36 inches. Management. — This type should be managed in the same way as Yellow- Gray Sandy Loam, Upland. Yellow-Gray Sandy Loam On Gravel (1564.4) Yellow-Gray Sandy Loam On Gravel occupies only .46 of a square mile. Nearly all of the areas occur along Rock river and in the pre-glacial Leaf river between Rock river and the village of Stillman Valley. The topography is undu- lating. Drainage is practically all vertical thru the gravel deposits. The gravel is so near the surface that the growing crops are affected during seasons of drouth. The Aj horizon, which is approximately 4 inches in thickness is a medium to coarse-grained, grayish yellow sandy loam. The A^ horizon, extending to about 17 inches in depth, is a mottled, yellow sandy loam or yellow sand. The B horizon in its upper 7 inches is a fairly compact, yellow clayey sand which rests on gravelly yellow sand. Management. — The management of this type is about the same as for Brown Sandy Loam On Gravel (1560.4). Since the type is low in organic matter and nitrogen, legumes should be grown wherever it is possible in the rotation. An application of about 2 tons of limestone an acre will aid the growth of legumes. Dune Sand (1581) Sand dunes occur in scattered areas thruout the terraces of the county associated with the sandy loam types. The dune formations are the result of wind action which has reworked the sand and deposited it in ridges. Near Oregon some of the sand dunes have had large blowouts formed in them. Some of the low-lying areas of sand are not true dune formations. This type in the terrace covers 1.07 square miles, or .14 percent of the area of the county. Drain- age is rapid because of seepage thru the open substrata, often causing mucky and 26 Soil Report No. 38 peaty spots adjacent to the dunes. However, most of these peaty spots are too small to be shown on the map. The Aj horizon varies from to 3 inches in thickness, depending on the amount of organic matter that has accumulated. It varies in color from a light brown to yellow sand. Below this horizon the material is uniformly a yellow sand to a depth of 4 feet or more. Management. — Most of the Dune Sand, Terrace, is not used for farming. Its use for cropping presents peculiar difficulties. The reader is referred to the discussion of Dune Sand, Upland, page 18. Brown-Gray Silt Loam On Tight Clay (1528) Brown-Gray Silt Loam On Tight Clay, Terrace, occupies only 32 acres. It is flat in topography and is poorly drained, owing to the compact, plastic clay layer which is almost impervious to the movement of water. Suggestions regard- ing its management may be secured from the Agricultural Experiment Station. Brown-Gray Sandy Loam On Tight Clay (1568) Brown-Gray Sandy Loam On Tight Clay occupies only about 32 acres. It occurs in Section 13, ToAvnship 22 North, Range 11 East. It is poorly drained owing to the compact subsoil and the seepage water which it receives. Most of this type is left in pasture. (d) RESIDUAL SOILS Residual soils are formed from the residue left in place from the weathering of the rock and by the accumulation of organic matter. Most of the residual soil areas are located along the present valley of Rock river and some of the pre- glacial valleys of small streams, where the former streams, as well as erosion, have swept all the glacial material from the rock and left it exposed. Sand (083) Residual Sand occurs along Rock river from Oregon to Grand Detour. Very few areas of this type occur at any great distance from Rock River. Along the north shore of the preglacial Kyte creek and north of Brookville some outcrops of sandstone occur. The topography of the type is rough to broken. It is non- agricultural except for some pasture. Some of the sand is being quarried for use in glass manufacturing. A characteristic of the sandstone bedrock is that it weathers and crumbles readily when exposed. The residual sand is gray or white, except where organic matter from the rotting leaf mold is incorporated in the upper part, forming a brown color to a depth of 1 or 2 inches. The type occupies about 3 square miles of the county. Management. — Pasture and permanent forestry are apparently the only ways in which this type can be utilized other than as a source for sand for industrial uses. Stony Loam, Limestone (098) Stony Loam, Limestone, occurs principally on the eroded slopes which are underlain with limestone near the surface. The stones vary in size from gravel Ogle County 27 to 6 or 8 inches in diameter. They are mixed with some soil material which may be either silty or sandy. The type occupies 3.62 square miles, or .47 percent of the area of the county. The only agricultural value of the type is for pasture and timber land. Stony Loam, Sandstone (098) Stony Loam, Sandstone, occurs in the region of the St. Peter's sandstone on the eroded slopes where the weathering processes have disintegrated the sand- stone to form broken pieces varying in diameter from 2 to 10 or 12 inches, mixed with sand. The type is of no agricultural value, even for pasturing purposes. Limestone Outcrop (099) Limestone Outcrop, which occupies altogether 198 acres, is found along Rock river and some of the small streams. The rock exposures vary in height from 20 to 125 or 150 feet. It is non-agricultural, aside from its value as a source of crushed limestone. In some localities, beyond hauling distance from shipping points, portable limestone crushers have been set up, thus furnishing neighboring farmers with ground limestone for agricultural use. There are numerous local quarry sites well distributed over the county. Sandstone Outcrop (099) Sandstone as an outcrop occupies only 51 acres. It is non-agricultural in value. The only interest in these areas lies in their scenic beauty. (e) LATE SWAMP AND BOTTOM-LAND SOILS This group includes the bottom lands along streams, the swamps, and the poorly drained lowlands. Much of the soil, therefore, is of alluvial formation and is largely subject to overflow. Overflow occurs, however, only during periods of excessive rains, and soon subsides. The swamps occupy the low marshy areas in the preglacial Rock river ter- race and some of the preglacial valleys formed by its tributaries. They also occupy the depressions in the upland that are often the sources of intermittent streams. This group includes only three soil types which occupy a total area of 64.52 square miles, or 8.56 percent of the area of the county. Black Mixed Loam (1450) Black Mixed Loam occupies 21.06 square miles, or 2.80 percent of the area of the county. The largest areas are located in the eastern part of the county in what is known as the preglacial Rock river terrace. The other areas are scat- tered thruout the upland, usually occurring as depressions in the undulating or rolling upland in which many of the small, intermittent streams find their sources. Much seepage and drainage water reaches these areas, thus providing optimum conditions for the accumulation of organic matter. Usually, the streams which flow thru these areas have no well-defined channels and remain sluggish thru lack of sufficient fall. However, in the larger areas, drainage is better established 28 Soil Report No. 38 thru the construction of dredges and the installation of tile. As the name indi- cates, Black Mixed Loam is black in color, and is made up of a number of types which would be shown on the map if they occurred in larger areas. The Aj horizon varies from a peaty loam or muck to a silt or sandy loam, brown to black in color. This horizon is rich in nitrogen and organic matter. The A2 horizon is usually a black clay loam. The B horizon is a fairly compact, plastic but pervious drab clay loam, which has some streaks of yellow at a depth of 36 to 40 inches. Management. — The first important factor in management of this type is good drainage, which is frequently difficult to obtain because of the lack of an outlet. The soil is very productive, tho it is alkaline in some spots. Good drain- age and the application of potash salts, manure, and straw will counteract the ill effects of the alkali. The installation of drainage has opened up many areas of this type for cultivation which were, until recently, used only for pasture. Mixed Loam (1454) Mixed Loam occurs as bottom land along Rock river as well as the small streams thruout the county. It usually takes the form of narrow strips rarely more than a quarter of a mile in width. The type occupies 43.08 square miles, or 5.71 percent of the area of the county. As the name indicates, this type is made up of a number of types, the areas of which are too small to be shown on the map. In texture it may be a silt loam, sandy loam, loam, or sand. In color it varies from a grayish yellow or yellow to a brown or black. Even if it were possible to indicate these different variations on the map, the first flood would probably leave a different mixture of soil material. For this reason it is im- possible to write a detailed description which will apply to the type as a whole. Management. — Practically all of this type is subject to overflow. The sedi- ment deposited at each flood maintains a good supply of the elements of plant food. Since there is danger of this type being flooded at any time, the general practice is to keep it in pasture instead of growing cultivated crops on it. Deep Peat (1401) Deep Peat occupies only .38 of a square mile in Ogle county. The deposits occur in scattered areas, none of which are large and most of which are poorly drained. To a depth of about 8 inches the type is a well-decomposed peat with its fibrous structure destroyed. Below this depth some fibrous material occurs. The proportion of fibrous material increases with increasing depth until the plastic, fairly compact, drab to black clay loam, which underlies the peat at a depth of about 40 inches, is reached. Management. — Very little effort has been made to farm the peat deposits in Ogle county because they are swampy and difficult to drain. The peat bogs in the pastures have many hummocks varying from 4 to 12 inches or more in height. Some areas have been put under cultivation, and, with an application of potas- sium salts, produce fair yields. APPENDIX EXPLANATIONS FOR INTERPRETING THE SOIL SURVEY CLASSIFICATION OF SOILS In order to interpret the soil map intelligently, the reader must understand something of the method of soil classification upon which the survey is based. Without going far into details the following paragraphs are intended to furnish a brief explanation of the general plan of classification used. The soil type is the unit of classification. Each type has definite charac- teristics upon which its separation from other types is based. These character- istics are inherent in the strata, or "horizons," which constitute the soil profile in all mature soils. Among them may be mentioned color, structure, texture, and chemical composition. Other items, such as native vegetation (whether timber or prairie), topography, and geological origin and formation, may assist in the differentiation of types, altho they are not fundamental to it. Since some of the terms used in designating the factors which are taken into account in establishing soil types are technical in nature, the following defi- nitions are introduced : Horizon. A layer or stratum of soil which differs discernibly from those adjacent in color, texture, structure, chemical composition, or a combination of these characteristics, is called an horizon. In describing a matured soil, three horizons designated as A, B, and C are usually considered. A designates the upper horizon and, as developed under the conditions of a humid, tem- perate climate, represents the layer of extraction or eluviation ; that is to say, material in solution or in suspension has passed out of this zone thru the processes of weathering. B represents the layer of concentration or illuviation ; that is, the layer developed as a result of the accumulation of material thru the downward movement of water from the A horizon. C designates the layer lying below the B horizon and in which the material has been less affected by the weathering processes. Frequently differences within a stratum or zone are discernible, in which case it is subdivided and described under such designations as A, and A3, Bj and Bj, etc. Soil Profile. The soil section as a whole is spoken of as the soil profile. Depth and Thickness. The horizons or layers which make up the soil profile vary in depth and thickness. These variations are distinguishing features in the separation of soils into types. Physical Composition. The physical composition, sometimes referred to as "texture," is a most important feature in characterizing a soil. The texture depends upon the rela- tive proportions of the following physical constituents: clay, silt, fine sand, sand, gravel, stones, and organic material. Structure. The term "structure" has reference to the aggregation of particles within the soil mass and carries such qualifying terms as open, granular, compact, columnar, laminated. Organic-Matter Content. The organic matter of soil is derived largely from plant tissue and it exists in a more or less advanced stage of decomposition. Organic matter forms the predominating constituent in certain soils of swampy formation. Color. Color is determined to a large extent by the proportion of organic matter, but at the same time it is modified by the mineral constituents, especially by iron compounds. Reaction. The term "reaction" refers to the chemical state of the soil with respect to acid or alkaline condition. It also involves the idea of degree, as strongly acid or strongly alkaline. Carbonate Content. The carbonate content has reference to the calcium carbonate (limestone) present, which in some cases may be associated with magnesium or other car- bonates. The depth at which carbonates are found may become a very important factor in determining the soil type. Topography. Topography has reference to the lay of the land, as level, rolling, hilly, etc. 29 30 Soil Keport No. 38: Appendix Native Vegetation. The vegetation or plant growth before being disturbed by man, as prairie grasses and forest trees, is a feature frequently recognized in differentiating soil types. Geological Origin. Geological origin involves the idea of character of rock materials composing the soil as well as the method of formation of the soil material. Not infrequently areas are encountered in which type characters are not distinctly developed or in which they show considerable variation. When these variations are considered to have sufficient significance, type separations are made whenever the areas involved are sufficiently large. Because of the almost infinite variability occurring in soils, one of the exacting tasks of tlie soil sur- veyor is to determine the degree of variation which is allowable for any given type. Classifying Soil Types.— In the system of classification used, the types fall first into four general groups based upon their geological relationships ; namely, upland, terrace, swamp and bottom land, and residual. These groups may be subdivided into prairie soils and timber soils, altho as a matter of fact this sub- division is applied in the main only to the upland group. These terms are all explained in the foregoing part of this Report in connection with the description of the particular soil types. Naming and Numbering Soil Types. — In the Illinois soil survey a system of nomenclature is used which is intended to make the type name convey some idea of the nature of the soil. Thus the name "Yellow-Gray Silt Loam" car- ries in itself a more or less definite description of the type. It should not be assumed, however, that this system of nomenclature makes it possible to devise type names which are adequately descriptive, because the profile of mature soils is usually made up of three or more horizons and it is impossible to describe each horizon in the type name. The color and texture of the surface soil are usually included in the type name and when material such as sand, gravel, or rock lies at a depth of less than 30 inches, the fact is indicated by the word ' ' On, ' ' and when its depth exceeds 30 inches, by the word "Over"; for example, Brown Silt Loam On Gravel, and Brown Silt Loam Over Gravel. As a further step in systematizing the listing of the soils of Illinois, recog- nition is given to the location of the types with respect to the geological areas in which they occur. According to a geological survey made many years ago, the state has been divided into seventeen areas with respect to geological forma- tion and, for the purposes of the soil survey, each of these areas has been assigned an index number. The names of the areas together with their general location and their corresponding index numbers are given in the following list. 000 Eesidual, soils formed in place thru disintegration of rocks, and also rock outcrop 100 Unglaciated, including three areas, the largest being in the south end of the state 200 Illinoisan moraines, including the moraines of the Illinoisan glaciations 300 Lower Illinoisan glaciation, formerly considered as covering nearly the south third of the state 400 Middle Illinoisan glaciation, covering about a dozen counties in the west-central part of the state 500 Upper Illinoisan glaciation, covering about fourteen counties northwest of the middle Illinoisan glaciation 600 Pre-Iowan glaciation, now believed to be part of the upper Illinoisan 700 lowan glaciation, lying in the central northern end of the state Ogle County 31 800 Peep loess areas, including a zone a few miles wide along the Wabash, Illinois, and Mississippi rivers 900 Early Wisconsin moraines, includingj;he moraines of the early Wisconsin glaciation 1000 Late Wisconsin moraines, including the moraines of the late Wisconsin glaciation 1100 Early Wisconsin glaciation, covering the greater part of the northeast quarter of the state 1200 Late Wisconsin glaciation, lying in the northeast corner of the state 1300 Old river-bottom and swamp lands, formed by material derived from the Illinoisan or older glaciations 1400 Late river-bottom and swamp lands, formed by material derived from the Wisconsin and lowan glaciations 1500 Terraces, bench or second bottom lands, and gravel outwash plains 1600 Lacustrine deposits, formed by Lake Chicago, the enlarged Glacial Lake Michigan Further information regarding these geological areas is given in connection with the general map mentioned above and published in Bulletin 123 (1908). Another set of index numbers is assigned to the classes of soils as based upon physical composition. The following list contains the names of these classes with their corresponding index numbers. Index Number Limits Class Names to 9 Peats 10 to 12 Peaty loams 13 to 14 Mucks 15 to 19 Clays 20 to 24 Clay loams 25 to 49 Silt loams 50 to 59 ... ! Loams 60 to 79 Sandy loams 80 to 89 Sands 90 to 94 Gravelly loams 95 to 97 Gravels 98 Stony loams 99 Rock outcrop As a convenient means of designating types and their location with respect to the geological areas of the state, each type is given a number made up of a combination of the index numbers explained above. This number indicates the type and the geological area in which it occurs. The geological area is always indicated by the digits of the order of hundreds while the balance of the number designates the type. To illustrate: the number 1126 means Brown Silt Loam in the early Wisconsin glaciation, 434 means Yellow-Gray Silt Loam of the mid- dle Illinoisan glaciation. These numbers are especially useful in designating very small areas on the map and as a check in reading the colors. A complete list of the soil types occurring in each county, along with their corresponding type numbers and the area covered by each type, will be found in the respective county soil reports in connection with the maps. SOIL SURVEY METHODS Mapping of Soil Types. — In conducting the soil survey, the county consti- tutes the unit of working area. The field work is done by parties of two to four men each. The field season extends from early in April to Thanksgiving. Dur- ing the winter months the men are engaged in preparing a copy of the soil map to be sent to the lithographer, a copy for the use of the county farm adviser until the printed map is available, and a third copy for use in the office in order to preserve the original official map in good condition. 32 Soil Report No. 38: Appendix An accurate base map for field use is necessary for soil mapping. These maps are prepared on a scale of one inch to the mile, the official data of the original or subsequent land survey being used as the basis in their construction. Each surveyor is provided with one of these base maiDS, which he carries with him in the field ; and the soil type boundaries, together with the streams, roads, railroads, canals, town sites, and rock and gravel quarries are placed in their proper location upon the map while the mapper is on the area. With the rapid development of road improvement during the past few years, it is almost in- evitable that some recently established roads will not appear on the published soil map. Similarly, changes in other artificial features will occasionally occur in the interim between the preparation of the map and its publication. The detail or minimum size of areas which are shown on the map varies somewhat, but in general a soil type if less than five acres in extent is not shown. A soil auger is carried by each man with which he can examine the soil to a depth of 40 inches. An extension for making the auger 80 inches long is taken by each party, so that the deeper subsoil may be studied. Each man carries a compass to aid in keeping directions. Distances along roads are measured by a speedometer or other measuring device, while distances in the field away from the roads are measured by pacing. Sampling for Analysis. — After all the soil types of a county have been located and mapped, samples representative of the different types are collected for chemical analysis. The samples for this purpose are usually taken in three depths ; namely, to 6% inches, 6% to 20 inches, and 20 to 40 inches, as explained in connection with the discussion of the analytical data beginning on page 7. PRINCIPLES OF SOIL FERTILITY Probably no agricultural fact is more generally known by farmers and land- owners than that soils differ in productive power. A fact of equal importance, not so generally recognized, is that they also differ in other characteristics such as response to fertilizer treatment and to management. The soil is a dynamic, ever-changing, exceedingly complex substance made up of organic and inorganic materials and teeming with life in the form of microorganisms. Because of these characteristics, the soil cannot be considered as a reservoir into which a given quantity of an element or elements of plant food can be poured with the assurance that it will respond with a given increase in crop yield. In a similar manner it cannot be expected to respond with per- fect uniformity to a given set of management standards. To be productive a soil must be in such condition physically with respect to structure and moisture as to encourage root development ; and in such condition chemically that injurious substances are not present in harmful amounts, that a sufficient supply of the elements of plant food become available or usable during the growing season, and that lime materials are present in sufficient abundance favorable for the growth of the higher plants and of the beneficial microorganisms. Good soil management under humid conditions involves the adoption of those tillage, crop- Ogle County 33 ping, and fertilizer treatment methods which will result in profitable and per- manent crop production on the soil type concerned. The following paragraphs are intended to state in a brief way some of the principles of soil management and treatment which are fundamental to profitable and continued productivity. CROP REQUIREMENTS WITH RESPECT TO PLANT-FOOD MATERIALS Ten of the chemical elements are known to be essential for the growth of the higher plants. These are carbon, hydrogen, oxygen, nitrogen, phospJwrus, sulfur, potassium, calcium, magnesium, and iron. Other elements are absorbed from the soil by growing plants, including manganese, silicon, sodium, aluminum, chlorin, and boron. It is probable that these latter elements are present in plants for the most part, not because they are required, but because they are dissolved in the soil water and the plant has no means of preventing their entrance. There is some evidence, however, which indicates that certain of these elements, notably manganese, silicon, and boron, may be either essential but required in only minute quantities, or very beneficial to plant growth under certain conditions, even tho not essential. Thus, for example, manganese has produced marked increases in crop yields on heavily limed soils. Sodium also has been found capable of partially replacing potassium in case of a shortage of the latter element. Table 5 shows the requirements of some of our most common field crops with respect to seven important plant-food elements furnished by the soil. The figures show the weight in pounds of the various elements contained in a bushel or in a ton, as the case may be. From these data the amount of an element re- moved from an acre of land by a crop of a given yield can easily be computed. Table 5. — Plant-Food Elements in Common Farm Crops' Produce Nitrogen Phos- phorus Sulfur Potas- sium Magne- sium Calcium Trnn Kind Amount Wheat, grain.. Wheat straw. . Corn, grain . . . Corn stover. . . Corn cobs. . . . Oats, grain Oats straw. . . . Clover seed . . . Clover hay . . . Soybean seed . Soybean hay. . Alfalfa hay . . . Ibu. 1 ton 1 bu. 1 ton 1 ton 1 bu. 1 ton 1 bu. 1 ton Ibu. 1 ton 1 ton lbs. 1.42 10.00 1.00 16.00 4.00 .66 12.40 1.75 40.00 3.22 43.40 52.08 lbs. .24 1.60 .17 2.00 .11 . 2.00 .50 5.00 .39 4.74 4.76 lbs. .10 2.80 .08 2.42 .06 4.14 '3;28 .27. 5.18 5.96 lbs. .26 18.00 .19 17.33 4.00 .16 20.80 .75 30.00 1.26 35.48 16.64 lbs. .08 1.60 .07 3.33 .04 2.80 .25 7.75 .15 13.84 8.00 lbs. .02 3.80 .01 7.00 .02 6.00 .13 29.25 .14 27.56 22.26 lbs. .01 .60 .01 1.60 .01 1.12 'i'66 'These data are brought together from various sources. Some allowance must be made for the exactness of the figures because samples representing the same kind of crop or the same kind of material frequently exhibit consid- erable variation. 34 Soil Report No. 38: Appendix PLANT-FOOD SUPPLY Of the elements of plant food, three (carbon, oxygen, and hydrogen) are secured from air and water, and the others from the soil. Nitrogen, one of the elements obtained from the soil by all plants, may also be secured from the air by the class of plants known as legumes, in case the amount liberated from the soil is insufficient ; but even these plants, which include only the clovers, peas, beans, and vetches among our common agricultural plants, are dependent upon the soil for the other six elements (phosphorus, potassium, magnesium, calcium, iron, and sulfur), and they also utilize the soil nitrogen so far as it becomes soluble and available dtTring their period of growth. The vast difference with respect to the supply of these essential plant-food elements in different soils is well brought out in the data of the Illinois soil survey. For example, it has been found that the nitrogen in the surface 6% inches, which represents the plowed stratum, varies in amount from 180 pounds per acre to more than 35,000 pounds. In like manner the phosphorus content varies from about 320 to 4,900 pounds, and the potassium ranges from 1,530 to about 58,000 pounds. Similar variations are found in all of the other essential plant-food elements of the soil. "With these facts in mind it is easy to understand how a deficiency of one of these elements of plant food may become a limiting factor of crop production. When an element becomes so reduced in quantity as to become a limiting factor of production, then we must look for some outside source of supply. Table 6 Table 6. — Plant-Food Elements in Manure, Rough Feeds, and Fertilizers^ Material Pounds of plant food of material per ton Nitrogen Phosphorus Potassium Fresh farm manure 10 16 12 10 40 43 50 80 280 310 400 80 20 2 2 2 2 5 5 4 8 180 250 250 125 "lo" 8 Corn stover 17 Oat straw 21 Wheat straw 18 Clover hay 30 Cowpea hay 33 Alfalfa hay 24 Sweet clover (water-free basis)' 28 Dried blood Sodium nitrate Ammonium sulfate Raw bone meal Steamed bone meal Raw rock phosphate Acid phosphate Potassium chlorid 850 Potassium sulfate 850 Kainit 200 Wood ashes' (unleached) 100 'See footnote to Table 5. Young second-year growth ready to plow under as green manure. *Wood ashes also contain about 1,000 pounds of lime (calcium carbonate) per ton. Ogle County 35 is presented for the purpose of furnishing information regarding the quantity of some of the more important plant-food elements contained in materials most commonly used as sources of supply. LIBERATION OF PLANT FOOD The chemical analysis of the soil gives the invoice of plant-food elements actually present in the soil strata sampled and analyzed, but the rate of libera- tion is governed by many factors, some of which may be controlled by the farmer, while others are largely beyond his control. Chief among the important con- trollable factors which influence the liberation of plant food are the choice of crops to be grown, the use of limestone, and the incorporation of organic matter. Tillage, especially plowing, also has a considerable effect in this connection. Feeding Power of Plants. — Different species of plants exhibit a very great diversity in their ability to obtain plant food directly from the insoluble minerals of the soil. As a class, the legumes — especially such biennial and perennial legumes as red clover, sweet clover, and alfalfa — are endowed with unusual power to assimilate from mineral sources such elements as calcium and phos- phorus, converting them into available forms for the crops that follow. For this reason it is especially advantageous to employ such leg-umes in connection with the application of limestone and rock phosphate. Thru their growth and subse- quent decay large quantities of the mineral elements are liberated for the benefit of the cereal crops which follow in the rotation. Moreover, as an effect of the deep-rooting habit of these legumes, mineral plant-food elements are brought up and rendered available from the vast reservoirs of the lower subsoil. Effect of Limestone. — Limestone corrects the acidity of the soil and supplies calcium, thus encouraging the development not only of the nitrogen-gathering bacteria which live in the nodules on the roots of clover, cowpeas, and other legumes, but also the nitrifying bacteria, which have power to transform the unavailable organic nitrogen into available nitrate nitrogen. At the same time, the products of this decomposition have power to dissolve the minerals contained in the soil, such as potassium and magnesium compounds. Organic Matter and Biological Action. — Organic matter may be supplied thru animal manures, consisting of the excreta of animals and usually accom- panied by more or less stable litter; and by plant manures, including green- manure crops and cover crops plowed under, and also crop residues such as stalks, straw, and chaff. The rate of decay of organic matter depends largely upon its age, condition, and origin, and it may be hastened by tillage. The chemical analysis shows correctly the total organic carbon, which constitutes, as a rule, but little more than half the organic matter; so that 20,000 pounds of organic carbon in the plowed soil of an acre corresponds to nearly 20 tons of organic matter. But this organic matter consists largely of the old organic residues that have accumulated during the past centuries becaase they were resistant to decay, and 2 tons of clover or cowpeas plowed under may have greater power to liberate plant-food materials than 20 tons of old, inactive organic matter. The history of the individual farm or field must be depended upon for information concerning 36 Soil Report No. 38: Appendix recent additions of active organic matter, whether in applications of farm manure, in legume crops, or in sods of old pastures. The condition of the organic matter of the soil is indicated to some extent by the ratio of carbon to nitrogen. Fresh organic matter recently incorporated with the soil contains a very much higher proportion of carbon to nitrogen than do the old resistant organic residues of the soil. The proportion of carbon to nitrogen is higher in the surface soil than in the corresponding subsoil, and in general this ratio is wider in highly productive soils well charged with active organic matter than in very old, worn soils badly in need of active organic matter. The organic matter furnishes food for bacteria, and as it decays certain decomposition products are formed, including much carbonic acid, some nitrous acid, and various organic acids, and these acting upon the soil have the power to dissolve the essential mineral plant foods, thus furnishing available phosphates, nitrates, and other salts of potassium, magnesium, calcium, etc., for the use of the growing crop. \ Effect of Tillage. — Tillage, or cultivation, also hastens the liberation of plant- food elements by permitting the air to enter the soil. It should be remembered, however, that tillage is wholly destructive, in that it adds nothing whatever to the soil, but always leaves it poorer, so far as plant-food materials are concerned. Tillage should be practiced so far as is necessary to prepare a suitable seed bed for root development and also for the purpose of killing weeds, but more than this is unnecessary and unprofitable; and it is much better actually to enrich the soil by proper applications of limestone, organic matter, and other fertilizing materials, and thus promote soil conditions favorable for vigorous plant growth, than to depend upon excessive cultivation to accomplish the same object at the expense of the soil. PERMANENT SOIL IMPROVEMENT According to the kind of soil involved, any comprehensive plan contemplat- ing a permanent system of agriculture will need to take into account some of the following considerations. The Application of Limestone The Function of Limestone. — In considering the application of limestone to land it should be understood that this material functions in several different ways, and that a beneficial result may therefore be attributable to quite diverse causes. Limestone provides calcium, of which certain crops are strong feeders. It corrects acidity of the soil, thus making for some crops a much more favorable environment as well as establishing conditions absolutely required for some of the beneficial legume bacteria. It accelerates nitrification and nitrogen fixation. It promotes sanitation of the soil by inhibiting the growth of certain fungous diseases, such as corn-root rot. Experience indicates that it modifies either directly or indirectly the physical structure of fine-textured soils, frequently to their great improvement. Thus, working in one or more of these different ways, limestone often becomes the key to the improvement of worn lands. Ogle County 37 How to Ascertain the Need for Limestone. — One of the most reliable indica- tions as to whether a soil needs limestone is the character of the growth of certain legumes, particularly sweet clover and alfalfa. These crops do not thrive in acid soils. Their successful growth, therefore, indicates the lack of sufficient acidity in the soil to be harmful. In case of their failure to grow the soil should be tested for acidity as described below. A very valuable test for ascertaining the need of a soil for limestone is found in the potassium thiocyanate test for soil acidity. It is desirable to make the +est for carbonates along with the acidity test. Limestone is calcium carbonate, while dolomite is the combined carbonates of calcium and magnesium. The natural occurrence of these carbonates in the soil is sufficient assurance that no limestone is needed, and the acidity test will be negative. On lands which have beers treated with limestone, however, the surface soil may give a positive test for carbonates, owing to the presence of undecomposed pieces of limestone, and at the same time a positive test for acidity may be secured. Such a result means either that insufficient limestone has been, added to neutralize the acidity, or that it has not been in the soil long enough to entirely correct the acidity. In making these tests, it is desirable to examine samples of soil from different depths, since carbonates may be present, even in abundance, below a surface stratum that is acid. Following are the directions for making the tasts : The Potassium Thiocyanate Test for Acidity. This test is made with a 4-perceiit solu- tion of potassium thiocyanate in alcohol- — 4 grams of potassium thiocyanate in 100 cubic centimeters of 95-percent alcohol.' When a small quantity of soil shaken up in a test tube with this solution gives a red color the soil is acid and limestone should be applied. If the solution remains colorless the; soil is not acid. An excess of water interferes with the reac- tion. The sample when tested, therefore, should be at least as dry as when the soil is in good tillable condition. For a prompt reaction the temperature of the soil and solution should be not lower than that of comfortable working conditions (60° to 75° Fahrenheit). The Hydrochloric Acid Test for Carbonates. Take a small representative sample of soil and pour upon it a few drops of hydrochloric (muriatic) acid, prepared by diluting the concentrated acid with an equal volume of water. The presence of limestone or some other carbonates will be fhown by the appearance of gas bubbles within 2 or 3 minutes, producing foaming or effervescence. The absence of carbonates in a soil is not in itself evidence that the soil is acid or that limestone should be applied, but it indicates that the confirmatory potassium thiocyanate test should be carried out. Amounts to Apply. — Acid soils should be treated with limestone whenever such application is at all practicable. The initial application varies with the degree of acidity and will usually range from 2 to 6 tons an acre. The larger amounts will be needed on strongly acid soils, particularly on land being pre- pared for alfalfa. When sufficient limestone has been used to establish condi- tions favorable to the growth of legumes, no further applications are necessary until the acidity again develops to such an extent as to interfere with the best growth of these crops. This will ordinarily be at intervals of several years. In the case of an inadequate supply of magnesium in the soil, the occasional use of magnesian (dolomitic) limestone would serve to correct this deficiency. Otherwise, so far as present knowledge indicates, either form of limestone — ' Since undenatured alcohol is difficult to obtain, some of the denatured alcohols have been tested for making this solution. Completely denatured alcohol made over U. S. Formulas No. 1 and No. 4, have been found satisfactory. Some commcTcial firms are also offering other preparations which are satisfactory. 38 Soil Report No. 38: Appendix high-calcium or magnesian — will be equally effective, depending upon the purity and fineness of the respective stones. Fineness of Material. — The fineness to which limestone is ground is an im- portant consideration in its use for soil improvement. Experiments indicate that a considerable range in this regard is permissible. Very fine grinding insures ready solubility, and thus promptness in action ; but the finer the grinding the greater is the expense involved. A grinding, therefore, that furnishes not too large a proportion of coarser particles along with the finer, similar to that of the by-product material on the market, is to be recommended. Altho the exact pro- portions of coarse and fine material cannot be prescribed, it may be said that a limestone crushed so that the coarsest fragments will pass thru a screen of 4 to 10 meshes to the inch is satisfactory if the total product is used. The Nitrogen Problem Nitrogen presents the greatest practical soil problem in American agricul- ture. Four important reasons for this are: its increasing deficiency in most soils ; its cost when purchased on the open market ; its removal in large amounts by crops; and its loss from soils thru leaching. Nitrogen usually costs from four to five times as much per pound as phosphorus. A 100-bushel crop of corn requires 150 pounds of nitrogen for its growth, but only 23 pounds of phosphorus. The loss of nitrogen from soils may vary from a few pounds to over one hundred pounds per acre, depending upon the treatment of the soil, the distribution of rainfall, and the protection afforded by growing crops. An inexhaustible supply of nitrogen is present in the air. Above each acre of the earth's surface there are about sixty-nine million pounds of atmospheric nitrogen. The nitrogen above one square mile weighs twenty million tons, an amount sufficient to supply the entire world for four or five decades. This large supply of nitrogen in the air is the one to which the world must eventually turn. There are two methods of collecting the inert nitrogen gas of the air and combining it into compounds that will furnish products for plant growth. These are the chemical and the biological fixation of the atmospheric nitrogen. Farmers have at their command one of these methods. By growing inoculated legumes, nitrogen may be obtained from the air, and by plowing under more than the roots of these legumes, nitrogen may be added to the soil. Inasmuch as legumes are worth growing for purposes other than the fixation of atmospheric nitrogen, a considerable portion of the nitrogen thus gained may be considered a by-product. Because of that fact, it is questionable whether the chemical fixation of nitrogen will ever be able to replace the simple method of obtaining atmospheric nitrogen by growing inoculated legumes in the pro- duction of our great grain and forage crops. It may well be kept in mind that the following amounts of nitrogen are required for the produce named : 1 bushel of oats (grain and straw) requires 1 pound of nitrogen. 1 bushel of corn (grain and stalks) requires iy2 pounds of nitrogen. 1 bushel of wheat (grain and straw) requires 2 pounds of nitrogen. 1 ton of timothy contains 24 pounds of nitrogen. 1 ton of clover contains 40 pounds of nitrogen. Ogle County 39 1 ton of cowpca hay contains 43 pounds of nitrogen. 1 ton of alfalfa contains 50 pounds of nitrogen. 1 ton of average manure contains 10 pounds of nitrogen. 1 ton of young sweet clover, at about the stage of growth when it is plowed under as green manure, contains, on water-free basis, 80 pounds of nitrogen. The roots of clover contain about half as much nitrogen as the tops, and the roots of cowpcas contain about one-tenth as much as the tops. Soils of mod- erate productive power will furnish as mucii nitrogen to clover (and two or three times as much to cowpeas) as will be left in the roots and stubble. In grain crops, .such as wheat, corn, and oats, about two-thirds of the nitrogen is con- tained in the grain and one-third in the straw or stalks. The Phosphorus Problem The element phosphorus is an indispensable constituent of every living cell. It is intimately connected with the life processes of both plants and animals, the nuclear material of the cells being especially rich in this element. The phosphorus content of the soil is dependent upon the origin of the soil. The removal of phosphorus by continuous cropping slowly reduces the amount of this element in the soil available for crop use, unless its addition is provided for by natural means, such as overflow, or by agi'icultural practices, such as the addition of phosphatic fertilizers and rotations in which deep-rooting, leguminous crops are frequently grown. It shoukrbe borne in mind in connection with the application of phosphate, or of any other fertilizing material, to the soil, that no benefit can result until the need for it has become a limiting factor in plant growth. For example, if there is already present in the soil sufficient available phosphorus to produce a forty-bushel crop, and the nitrogen supply or the moisture supply is sufficient for only forty bushels, or less, then extra phosphorus added to the soil cannot increase the yield beyond this forty-bushel limit. There are several different materials containing phosphorus which are applied to land as fertilizer. The more important of these are bone meal, acid phosphate, natural raw rock phosphate, and basic slag. Obviously that carrier of phosphorus which gives the most economical returns, as considered from all standpoints, is the most suitable one to use. Altho this matter has been the subject of much discussion and investigation the question still remains unsettled. Proba])ly there is no single carrier of phosphorus that will prove to be the most economical one to use under all circumstances because so much depends upon soil conditions, crops grown, length of haul, and market conditions. Bone meal, prepared from the bones of animals, appears on the market in two different forms, raw and steamed. Raw bone meal contains, besides the phasphorus, a considerable percentage of nitrogen which adds a useless expense if the material is purchased only for the sake of the phosphorus. As a source of phosphorus, steamed bone meal is preferable to raw bone meal. Steamed bone meal is prepared by extracting most of the nitrogenous and fatty matter from the bones, thus producing a more nearly pure form of calcium phosphate con- taining about 10 to 12 percent of the element phosphorus. 40 Soil Report No. 38: Appendix Acid phosphate is produced by treating rock phosphate with sulfuric acid. The two are mixed in about equal amounts; the product therefore contains about one-half as much phosphorus as the rock phosphate itself. Besides phos- phorus, acid phosphate also contains sulfur, which is likewise an element of plant food. The phosphorus in acid phosphate is more readily available for absorption by plants than that of raw rock phosphate. Acid phosphate of good quality should contain 6 percent or more of the element phosphorus. Rock phosphate, sometimes called floats, is a mineral substance found in vast deposits in certain regions. The phosphorus in this mineral exists chem- ically as tri-calcium phosphate, and a good grade of the rock should contain 121/^ percent, or more, of the element phosphorus. The rock should be ground to a powder, fine enough to pass thru a 100-mesh sieve, or even finer. The relative cheapness of raw rock phosphate, as compared with the treated or acidulated material, makes it possible to apply for equal money expenditure considerably more phosphorus per acre in this form than in the form of acid phosphate, the ratio being, under the market conditions of the past several years, about 4 to 1. That is to say, under these market conditions, a dollar will pur- chase about four times as much of the element phosphorus in the form of rock phosphate as in the form of acid phosphate, which is an important consideration if one is interested in building up a phosphorus reserve in the soil. As explained above, more very carefully conducted comparisons on various soil types under various cropping systems are needed before definite statements can be given as to which form of phosphate is most economical to use under any given set of conditions. Basic slag, known also as Thomas phosphate, is another carrier of phos- phorus that might be mentioned because of its considerable usage in Europe and eastern United States. Basic slag phosphate is a by-product in the manu- facture of steel. It contains a considerable proportion of basic material and therefore it tends to influence the soil reaction. Rock phosphate may be applied at any time during a rotation, but it is applied to the best advantage either preceding a crop of clover, which plant seems to possess an unusual power for assimilating the phosphorus from raw phosphate, or else at a time when it can be plowed under with some form of organic matter such as animal manure or green manure, the decay of which serves to liberate the phosphorus from its insoluble condition in the rock. It is important that the finely ground rock phosphate be intimately mixed with the organic material as it is plowed under. In using acid phosphate or bone meal in a cropping system which includes wheat, it is a common practice to apply the material in the preparation of the wheat ground. It may be advantageous, however, to divide the total amount to be used and apply a portion to the other crops of the rotation, particularly to corn and to clover. The Potassium Problem Our most common soils, which are silt loams and clay loams, are well stocked with potassium, altho it exists largely in a slowly soluble form. Such soils as Ogle County 41 sands and peats, however, are likely to be low in this element. On such soils this deficiency may be remedied by the application of some potassium salt, such as potassium sulfate, potassium chlorid, kainit, or other potassium compound, and in many instances this is done at great profit. From all the facts at hand it seems, so far as our great areas of common soils are concerned, that, with a few exceptions, the potassium problem is not one of addition but of liberation. The Rothamsted records, which represent the oldest soil experiment fields in the world, show that for many years other soluble salts have had practically the same power as potassium salts to increase crop yields in the absence of sufficient decaying organic matter. Whether this action relates to supplying or liberating potassium for its own sake, or to the power of the soluble salt to increase the availability of phosphorus or other elements, is not known, but where much potassium is removed, as in the entire crops at Rothamsted, Avith no return of organic residues, probably the soluble salt func- tions in both ways. Further evidence on this matter is furnished by the Illinois experiment field at Fairfield, where potassium sulfate has been compared with kainit both with and without the addition of organic matter in the form of stable manure. Both sulfate and kainit produced a substantial increase in the yield of corn, but the cheaper salt — kainit — was just as effective as the potassium sulfate, and returned some financial profit. Manure alone gave an increase similar to that produced by the potassium salts, but the salts added to the manure gave very little increase over that produced by the manure alone. This is explained in part, perhaps, by the fact that the potassium removed in the crops is mostly returned in manure properly cared for, and perhaps in larger part by the fact that decaying organic matter helps to liberate and hold in solution other plant-food elements, especially phosphorus. In laboratory experiments at the Illinois Experiment Station, it has been shown that potassium salts and most other soluble salts increase the solubility of the phosphorus in soil and in rock phosphate; also that the addition of glucose with rock phosphate in pot-culture experiments increases the availability of the phosphorus, as measured by plant growth, altho the glucose consists only of car- bon, hydrogen, and oxygen, and thus contains no limiting element of plant food. In considering the conservation of potassium on the farm it should be re- membered that in average livestock farming the animals destroy two-thirds of the organic matter and retain one-fourth of the nitrogen and phosphorus from the food they consume, but that they retain less than one-tenth of the potassium ; so that the actual loss of potassium in the products sold from the farm, either in grain farming or in livestock farming, is negligible on land containing 25,000 pounds or more of potassium in the surface 6% inches. The Calcium and Magnesium Problem When measured by crop removals of the plant-food elements, calcium is often more limited in Illinois soils than is potassium, while magnesium may be occasionally. In the case of calcium, however, the deficiency is likely to develop more rapidly and become much more marked because this element is leached 42 Soil Report No. 38: Appendix out of the soil in drainage water to a far greater extent than is either magnesium or potassium. The annual loss of limestone from the soil depends, of course, upon a num- ber of factors aside from those which have to do with climatic conditions. Among these factors may be mentioned the character of the soil, the kind of limestone, its condition of fineness, the amount present, and the sort of farming practiced. Because of this variation in the loss of lime materials from the soil, it is impossible to prescribe a fixed practice in their renewal that will apply uni- versally. The tests for acidity and carbonates described above, together with the behavior of such lime-loving legumes as alfalfa and sweet clover, will serve as general indicators for the frequency of applying limestone and the amount to use on a given field. Limestone has a direct value on some soils for the plant food which it supplies, in addition to its value in correcting soil acidity and in improving the physical condition of the soil. Ordinary limestone (abundant in the southern and western parts of Illinois) contains nearly 800 pounds of calcium per ton; while a good grade of dolomitic limestone (the more common limestone of north- ern Illinois) contains about 400 pounds of calcium and 300 pounds of magnesium per ton. Both of these elements are furnished in readily available form in ground dolomitic limestone. The Sulfur Question In considering the relation of sulfur in a permanent system of soil fertility it is important to understand something of the cycle of transformations that this element undergoes in nature. Briefly stated this is as follows: Sulfur exists in the soil in both organic and inorganic forms, the former being gradually converted to the latter form thru bacterial action; In this inorganic form sulfur is taken up by plants which in their physiological pro- cesses change it once more into an organic form as a constituent of protein. When these plant proteins are consumed by animals, the sulfur becomes a part of the animal protein. When these plant and animal proteins are decomposed, either thru bacterial action, or thru combustion, as in the burning of coal, the sulfur passes into the atmosphere or into the soil solution in the form of sulfur dioxid gas. This gas unites with oxygen and water to form sulfuric acid, which is readily washed back into the soil by the rain, thus completing the cycle, from soil — to plants and animals — to air — to soil. In this way sulfur becomes largely a self-renewing element of the soil, altho there is a considerable loss from the soil by leaching. Observations taken at the Illinois Agricultural Experiment Station show that 40 pounds of sulfur per acre are brought into the soil thru the annual rainfall. With a fair stock of sulfur, such as exists in our common types of soil, and with an annual return, which of itself would more than suffice for the needs of maximum crops, the maintenance of an adequate sulfur supply presents little reason at present for serious concern. There are regions, however, where the natural stock of sulfur in the soil is not nearly so high and where the amount returned thru rainfall is small. Under such circumstances sulfur soon becomes a limiting element of Ogle County 43 crop production, and it will be necessary sooner or later to introduce this sub- stance from some outside source. Investigation is now under way to determine to what extent this situation may apply under Illinois conditions. Physical Improvement of Soils In the management of most soil types, one very important matter, aside from proper fertilization, tillage, and drainage, is to keep the soil in good physical condition, or good tilth. The constituent most important for this purpose is organic matter. Organic matter in producing good tilth helps to control wash- ing of soil on rolling land, raises the temperature of drained soil, increases the moisture-holding capacity of the soil, slightly retards capillary rise and conse- quently loss of moisture by surface evaporation, and helps to overcome the tendency of some soils to run together badly. The physical effect of organic matter is to produce a granulation or mellow- ness, by cementing the fine soil particles into crumbs or grains about as large as grains of sand, which produces a condition very favorable for tillage, percolation of rainfall, and the development of plant roots. Organic matter is undergoing destruction during a large part of the year and the nitrates produced in its decomposition are used for plant growth. Altho this decomposition is necessary, it nevertheless reduces the amount of organic matter, and provision must therefore be made for maintaining the supply. The practical way to do this is to turn under the farm manure, straw, cornstalks, weeds, and all or part of the legumes produced on the farm. The amount of legumes needed depends upon the character of the soil. There are farms, espe- cially grain farms, in nearly every community where all legumes could be turned under for several years to good advantage. Manure should be spread upon the land as soon as possible after it is pro- duced, for if it is allowed to lie in the barnyard several months as is so often the case, from one-third to two-thirds of the organic matter will be lost. Straw and cornstalks should be turned under, and not burned. There is considerable evidence indicating that on some soils undecomposed straw applied in excessive amount may be detrimental. Probably the best practice is to apply the straw as a constituent of well-rotted stable manure. Perhaps no form of organic matter acts more beneficially in producing good tilth than cornstalks. It is true, they decay rather slowly, but it is also true that their durability in the soil is exactly what is needed in the production of good tilth. Furthermore, the nitrogen in a ton of cornstalks is one and one-half times that of a ton of manure, and a ton of dry cornstalks incorporated in the soil will ultimately furnish as much humus as four tons of average farm manure. When burned, however, both the humus-making material and the nitrogen are lost to the soil. It is a common practice in the corn belt to pasture the cornstalks during the winter and often rather late in the spring after the frost is out of the ground. This trampling by stock sometimes puts the soil in bad condition for working. It becomes partially puddled and will be cloddy as a result. If tramped too late in the spring, the natural agencies of freezing and thawing and wetting and drying, with the aid of ordinary tillage, fail to produce good tilth before 44 Soil Report No. 38: Appendix the crop is planted. Whether the crop be corn or oats, it necessarily suffers and if the season is dry, much damage may be done. If the field is put in corn, a poor stand is likely to result, and if put in oats, the soil is so compact as to be unfavorable for their growth. Sometimes the soil is worked when too wet. This also produces a partial puddling which is unfavorable to physical, chemical, and biological processes. The effect becomes worse if cropping has reduced the organic matter below the amount necessary to maintain good tilth. Systems of Crop Rotations In a program of permanent soil improvement one should adopt at the outset a good rotation of crops, including, for the reasons discussed above, a liberal use of legumes. No one can say in advance for every particular case what will prove to be the best rotation of crops, because of variation in farms and farmers and in prices for produce. As a general principle the shorter rotations, with the frequent introduction of leguminous crops, are the better adapted for build- ing up poor soils. Following are a few suggested rotations which may serve as models or out- lines to be modified according to special circumstances. Six- Year notations First year — Corn Second year -^Corn Third year — Wheat or oats (with clover, or clover and grass) Fourth year — Clover, or clover and grass Fifth year — Wheat (with clover), or grass and clover Sixth year — Clover, or clover and grass In grain farming, with small grain grown the third and fifth years, most of the unsalable products should be returned to the soil, and the clover may be clipped and left on the land or returned after threshing out the seed; or, in livestock farming, the field may be used three years for timothy and clover pas- ture and meadow if desired. The system may be reduced to a five-year rotation by cutting out either the second or the sixth year, and to a four-year system by omitting the fifth and sixth years, as indicated below. The two following rotations are suggested as especially adapted for com- bating the corn borer : First year — Com First year — Corn Second year — Soybeans Second year —Soybeans Third year -Small grain (with legume) Third year — Small grain (with legdme) Foiirth year — Legume Fourth year — Legume Fifth year — Corn (for silage) Fifth year — Wheat (with alfalfa) Sixth year — Wheat (with sweet clover) Sixth year — Alfalfa Five- Year Rotations First year — Corn Second year — Wheat or oats (with clover, or clover and grass) Third year — Clover, or clover and grass Fourth year — Wheat (with clover), or clover and grass Fifth year ■ — Clover, or clover and grass First year — Corn Second year — Soybeans Third year — Corn Fourth year — Wheat (with legume) Fifth year ■ — Legume Ogle County 45 First year — Corn Second year — Covvpcas or soybeans Third year — Wheat (with clover) Fourth year — Clover Fifth year ■ — Wheat (with clover) The last rotation mentioned above allows legumes to be grown four times. Alfalfa may be grown on a sixth field, rotating over all the fields if moved every six years. Four- Year Rotations First year — Corn Second year — Wheat or oats (with clover) Third year — Clover -Wheat (with clover) Fourth year First year ■ — Corn Second year — Cowpeas or soybeans Third year — Wheat (with clover) Fourth year — Clover First year — Corn Second year — Corn T]iird year — Wheat or oats (with clover) Fourth year — Clover First year —Wheat (with clover) Second year — Clover Third year — Corn Fourth year — Oats (with clover) Alfalfa may be grown on a fifth field for four or eight years, which is to be alternated with one of the four ; or the alfalfa may be moved every 3ve years, and thus rotated over all five fields every twenty-five years. Three-Year Rotations First year — Corn First year Second year — Oats or wheat (with clover) Second year Third year — Clover Third year -Wheat or oats (with clover) -Corn -Cowpeas or soybeans By allowing the clover, in the last rotation mentioned, to grow in the spring before preparing the land for corn, we have provided a system in which legumes grow on every acre every year. This is likewise true of the following suggested two-year system: Two- Year Rotations First year — Oats or wheat (with sweet clover) Second year — Corn Altho in this two-year rotation either oats or wheat is suggested, as a matter of fact, by dividing the land devoted to small grain, both of these crops can be grown simultaneously, thus providing a three-crop system in a two-year cycle. It should be understood that in all of the above suggested cropping systems it may be desirable in some cases to substitute barley or rye for the wheat or oats. Or, in some cases, it may become desirable to divide the acreage of small grain and grow in the same j-ear more than one kind. In all of these proposed rotations the word clover is used in a general sense to designate either red clover, alsike clover, or sweet clover, or it may include alfalfa used as a biennial. The mixing of alfalfa with clover seed for a legume crop is a recommendable practice. The value of sweet clover, especially as a green manure for building up depleted soils, as well as a pasture and hay-crop, is becoming tlioroly established, and its im- portance in a crop-rotation program may well be emphasized. SUPPLEMENT: EXPERIMENT FIELD DATA {Results from Experiment Fields on Soil I'ypes Similar to TJiose Occurring in Ogle County) The University of Illinois has conducted altogether about fifty soil experi- ment fields in different sections of the state and on various types of soil. Altho some of these fields have been discontinued, the majority are still in operation. It is the present purpose to report the summarized results from certain of these fields located on types of soil described in the accompanying soil report. A few general explanations at this point, which apply to all the fields, will relieve the necessity of numerous repetitions in the following pages. Size and Arrangement of Fields The soil experiment fields vary in size from less than two acres up to 40 acres or more. They are laid off into series of plots, the plots commonly being either one-fifth or one-tenth acre in area. Each series is occupied by one kind of crop. Usually there are several series so that a crop rotation can be carried on with every crop represented every year. Two Farming Systems Provided On many of the fields the treatment provides for two distinct, systems of farming, livestock farming and grain farming. In the livestock system, stable manure is used to furnish organic matter and nitrogen. The amount applied to a plot is based upon the amount that can be produced from crops raised on that plot. In the grain system no animal manure is used. The organic matter and nitrogen are applied in the form of plant manures, including the plant residues produced, such as cornstalks, straw from wheat, oats, clover, etc.^ along with leguminous catch crops plowed under. It is the plan in this latter system to remove from the land, in the main, only the grain and seed produced, except in the case of alfalfa, that crop being harvested for hay the same as in the livestock system. Certain modifications have been introduced in recent years. Definite Crop Rotations Followed Crops which are of interest in the respective localities are grown in definite rotations. The most common rotation used is wheat, corn, oats, and clover; and often these crops are accompanied by alfalfa growing on a fifth series. In the grain sj^stem a legume catch crop, usually sweet clover, is included, which is seeded on the young wheat in the spring and plowed under in the fall or in the following spring in preparation for corn. If the red clover crop fails, soy- beans are substituted. Soil Treatment The treatment applied to the plots has, for the most part, been standardized according to a rather definite system, altho deviations from this system occur now and then, particularly in the older fields. 46 Ogle County 47 Following is a brief explanation of this standard system of treatment. Animal Manures. — Animal manures, consisting of excreta from animals, with stable litter, are spread upon the respective plots in amounts proportionate to previous crop yields, the applications being made in the preparation for corn. Plant Manures. — Crop residues produced on the land, such as stalks, straw, and chaff, are returned to the soil, and in addition a green-manure crop of sweet clover is seeded in small grains to be plowed under in preparation for corn. (On plots where limestone is lacking the sweet clover seldom survives.) This practice is designated as the residues system. Mineral Manures. — The yearly acre-rates of application have been : for lime- stone, 1,000 pounds; for raw rock phosphate, 500 pounds; and for potassium, usually 200 pounds of kainit. When kainit was not available, owing to conditions brought on by the World war, potassium carbonate was used. The initial applica- tion of limestone has usually been 4 tons per acre. Explanation of Symbols Used = Untreated land or check plots M = Manure (animal) R = Residues (from crops, and includes legumes used as green manure) L = Limestone P = Phosphorus, in the form of rock phosphate unless otherwise designated (aP=--acid phosphate, bP^bonemeal, rP = rock phosphate, sP = slag phosphate) K =: Potassium (usually in the form of kainit) N = Nitrogen (usually in the form contained in dried blood) Le = Legume used as green manure Cv = Cover crop ( ) = Parentheses enclosing figures, signifying tons of hay, as distinguished from bushels of seed I = Heavy vertical rule, indicating the beginning of complete treatment II = Double vertical rule, indicating a radical change in the cropping system. In discussions of this sort of data, financial profits or losses based upon assigned market values are frequently considered. However, in view of the erratic fluctuations in market values — especially in the past few years — it seems futile to attempt to set any prices for this purpose that are at all satisfactory. The yields are therefore presented with the thought that with these figures at hand the financial returns from a given practice can readily be computed upon the basis of any set of market values that the reader may choose to apply. THE MT. MORRIS FIELD A University soil experiment field located in Ogle county has been in opera- tion for the past sixteen years. This field is situated near the center of the county at the edge of the town of Mt. Morris. The soil type as shown on the county map is Brown Silt Loam but, as explained in the description of the Brown Silt Loam, this type as mapped in Ogle county embraces several variations. A detailed examination of the soil of the Mt. Morris field discloses five distinguish- able types which, on a large-scale map, can be indicated. Such a map is pre- 48 Soil Report No. 38: Supplement :z5:;iH L'g^^t Brown S'lt Loam^ shallow phd5e -r---ll Tama s0 03 00 —1 t^ 00 00 03 IN 5i > »0 CO t^ 00 CO lO 03 CO CD Ol o> -a Oi CO N OS «:> -H 00 o o -^ IN CO ■* CO ' 5 IN O 00 N CO —1 t^ 03 Ol —1 (N f* t~ r^ IN 1-1 03 t>- 00 00 00 r— I o CT) O lO (N 00 ■* CO 03 ^ O t^ ^ -^ o M (N C^ C^^^ ^ O lo i> 00 00 >0 CO 03 03 03 in ■* <5 OJ 1^ o 00 t^ O lO CO C-) cr > c TjH eo IN ^ O) ■* 00 o O Ol ^ "S Lh 2cS O —■ O IN t- o t^ c^ CO cr > ,9 ,-. CO O lO IN 00 CO lO 00 t^ o 00 o> Oi CO t^ CO t^ t^ CC ) O CO •<)< "O lO CO CO -* T(i ^ CO CO C ^ 00 -H CO CD 00 .-H -^ 03 c ^ "S tn 00 CD CO 00 o> o CO o r^ t^ CD Tji CD lO c J3 00 ■* CD 00 CO 1^ O "O 00 in -< O CO 5D t^ to CO ^ CO CO t^ ■0 00 CO t^ lO S IN 00 O 00 CO r^ i^ CO 03 t^ C-) « > rt (N CO O 03 00 >c 00 03 Tjl O) ^ 00 1* IN -H CO •* OS o I-H *— o -^ CT CO Tt< 'J* CO CO CO ^ Ttl c 6 (N CO CO CO < oi co' CO CO oi CO J? o o o ^ 5? t^ o Ir >" i2 lO 03 CO CO CO t^ CO 03 in 03 =^ ^ lO O 00 03 O -H ^ -H IN T ! 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IS 05 O r~ h- O O CO CM o >o 1 « lO O OS OS OS CO ^t C3S CO d 1 (N « S" -H r- CO rH lO -H O CO o ^1 05 -C m -* CO ■^ a^ ^ m >6 00 CM O ' - pf C5 CO Tf ^ Ol CO ■* '*< CO CO 2 s s s s CM CO 3, 2^ ■"«< CM c^ « ' ^ on on S" o £" o5 o lO" ^ Vi CO OS t^ ■* 1^ r^ Tj< CO 00 UO CO lO r> t^ 03 CO rt >0 ^ o t; ' o> o s CM CO r^ OS ■ CD C7S -^t CD lO CM 1 -^ O " r-c c^ ^ -1 IN CM 2- ci 1 ^ CO i<}< lO lO CO CO 10 "O lO c M M ■* o IN in 00 CD O --I CO O 1 C t^ ira 00 00 t^ O >0 CD o (■ 2 2(S <- M C^) IN o ■^ CO t^ CD CO lO o CO CO Tj< CM t^ CO O <3S o o t- 00 00 T)H lO t^ (^ 00 -t O CO t^ l> 00 CO I - 00 t^ OS ci 5 -H C IN r> t^ CO CO tv -H h C3 TjH Tjf CO 00 Tt< CO t^ 00 00 o ■N- Oi O •^ O CD CO ■* OS c 3 J3 OS — CO "O t~ CD C» CO CO ^ ' - O lO !D r^ t~ lO TjH CD CO CO T ' ^ N CO CO CO CM CM CM CO CO c M CO CO CO CM ■o 3 c:s CO CO t^ CO c Tt "O IN CM 00 O CO lO Q 3 ® -H TfH -H CO CO -ri i<* CO co' c- ^ a IN 0) > CO —1 OS 00 - 05 -C M" c^ CO co' CO -H CM 00 00 c- 1 o ^_^ ^^^ ^^^ J o "S CO T). 'Ji Tf< CM CO ■* Tt< ■* c ' o —1 CM CM cm' -H t^ OS O O CM lO CO ^ -H -H -H •— 1 ^_f s_ ^ — ' -.-y ^-^ 2 i> S 0. o CO w on ■* 05 CM O O t~- ic CO CM CO O C3S CS tH C3S o c = ^ CO >o 00 CO • -^ H o (N U3 d d OS — 1 d cm d >0 O Tji >o 00 IT q OS -H M ^ rt -H cq CM lO CO o >o lO CD CD CD CO 11 3 -^ CO GO '* 00 o> ■* 00 CM rt< O 05 CO c^ ! S CM Tt< -H — 1 O --1 rM CO -1 C£ = -^ t^ CO ■* (N o) 00 ira CO O f > rR •O O 'f lO t^ 00 1< 00 OS If 5 M t~ t^ t^ 00 00 t^ t^ t^ t^ t- o lO t^ t^ 1^ lO CD l^ t^ t^ ir 3 oj in ^ s t^ c 03 (N CM ^ o o t^ t^ T|< C 3 ca -H 00 lo 00 00 —1 "O CD — H r s is o en o 00 00 CO 1^ —1 00 00 -H CO C > J3 t^ t^ -H W t^ 0) -H CO CO »r 5 t^ ri o (N ■* >o 'O CO CO ■* "O "O c ' ^ -H -H _^ t- 5 -^ ^ S CO CD 00 00 o t~ CO 00 t^ cv V CO Tj( OS -H 00 o t^ o CM r^ > -H t~ O O >0 lO CO IC o OS -a CO t^ en ^ t-^ OS CM CO 00 - o -^ CM — 1 .-( CM CM CM Cv ' u cm' cm" CO CO c^ 1 -o "" ^ M u ira c >o -f on tH CM o CM ^^ 00 t^ o o o -t< TtH t^ 1^ CM CO cr S 01 CO c^ IN tH >0 Tt< ^ o a > o ; a o> o d t~. t-i OS d tp t^ t^ r^ -^ G •* T)! ■*" •^ c t^ CO CD CO CD CD lO >0 »o r^ 'f -*J ^ 03 C' ^ lO t~- 00 O O CM CM - c C-1 CO CO 00 >o ir IS 25 1^ CO •o CO d t>^ CO ^ c (h 00 -< CO 00 00 d T)<' d 1--^ r^ : fs lO lO >o T)< lO ■* lO lO ^ o lO t~ t> CO lO lO CO CO CD ir ) d M a IT OJ t^ ^ Tji w CM 00 OS IT 03 CM CM lO CO 00 lo o CO 00 c 2c3 r* IN o r~ 00 CO OS CD 00 " ^ lO CO OS CO I^ CO CM CO CO r . 'J 1^ lO CO CO t~. CO tr is: CM CM CM CO CM CO CO CO CO c 3 » IN >> *i. ^^ ^^ , ^ , ^ , , ^ o CO 00 CO lO CM OS -1< CO oc (U o t^ 1^ lo CO CM CM lO t^ r> > -H CD 00 t^ t^ ■* ■* CM o' !3 —1 ■o CO w d — 1 CO OS o o « CO CO CO CO CO CO CO CO CO CV ^ CM CM CM C-l CM -H -H — 1 ,_H C\ - s^ o ^ 1 ^ (^ CO o -*< CO "O OS CO C3S OJ % CM CD CO CO CO O -H CO CO 1- >* c o> o ca ^ M _» c 00 CO r~ >o 00 "o OS CO oc a o CO o o lO »r —I 00 00 c o " " " o CO CO CO r^ CO CO t^ CO CD CC 0) 3 ■a o "i c^ 1-H 00 CD OS ^^ 00 'O -H IT. a CO — 1 c:s 00 -< c CM CO OS CS i(i en a -t CO d ^ d 00 lo CM 00 o) s Tj< lo d "O t^ C^ -^ d d rc « -i O lO >o >o •O t^ CO 1^ CD (^ CO o CO CO CO CO CO -"t ■* T)< 1* c "^ Soil treatment applied oi • Ph 0- ■ oi oi Oh c o s 03 c »*. J rt c PC l-I tf c c ^ O u H ^^ >! 3 C 1 c ci ^ a t; H :j ^ v^ — >> -Oi3 CO ^ o^t J3 « S— 1 lO ^ !U ■<*<'t lOiO c 00 cooo ^13 0> Ci 03 ^^^^ IC '^ 00 305 Qj oooioi ic C CD 00 'fi CD *^- cTco co^ C^J Ti 00 rocv -r tn "03 CO ^ ^ C2 c: CO CO -H ,-H CD^ CO CO '^^ 00^-- co-^t^t^ t^ 00 00 00 ^ caco^ ■<* -^^-^w >-, .M t^ 03 ^^^_ -* > oj CO 00 >o lO o3 OCO -H -rf 2 ^ ^23 C2Tt< d — 05 ^ CD CO t^ C^ CO-^ Tt 10 CD CD 10 y—( T-H -< CO co;2i,:2!- c3 ro C (M Tf CO O) a>-0 CD 00 00 CD 10 CO CO C) OOioS? <^' fc: (D > Ci < CO^iCiO -4.3 b >> c5 ^^^^ Oa 0) o "O C O00 00C5 e-t-H CO 0200 0^ (U > OJ OS C3 OC = "S ^ c3 C^ 02 CO 10 05 k O HI C3 c Ci C- t+H CO -H ^ CJ ^^ CO Tt< CO CC ^ 10 CO lO 10 ^ CO CO CO ■* ^ cot^ CO ""^ ^ "" ^^ — ^-.'S ^^ cS ai ^^^^ OS to 33 CC^ t^t^OCT ■* l^ 02 CJt^CQ OCOO^S' ZJ cS ■* >o -^ cv; "oS OCO -H 03 "3 ^1 , lO t^O CQ In." 05^ 1-4 "* ood ^< ciJS^^ < •^ lO 10 >o 10 10 »o CO CO CO CO (31 ^^ ^-^^ ■' Ph 1-4 1— ( 1— 1 1— 1 < a r^3 2I s 3 : : : : to 00 CO 10 00 ^dcoc2 "03 — ^— . 02 CO cj '-H ^ CJ ^ > ^^^^ to 'c3 ^^^^ 'c3 .^ 1915 Barle, hay CQ CO COO- 00 t^ 10 00 t4_, ^CD t^ ^ Soiod 5 iOCO 05 t~- 15 --I 10 CD 'rt 02 00 >o 02 t^ CD Cl lO C3 05 -H ^ 02 CD 10 CO 1— 1 lO lO lO »o i—i ■^ -^ -"Tf Tt4 tfl " ^^ — "" o- ^ C4 ca CI -< ^ — ■" ^ ■- ^ <; 03 -a »3 ^B '—J CO ^cot^ t^ 02 CO CD '1 lO »o •* t^ 00 00 com <>H .... ca rH t-iOl^t-- •0 lO CO CO 10 LO CD CD 10 lO lO iC j3 Om ^ -H ^ < < ^ to ": "^ '^; 00 23 >0 -M CO t^ 3 S ^ .... a: i2 oa CO ■-+< r- 03 S ^ * — ' —I -X5 X = ^ 8 Oh i-H ^H ^H 01 -r; ^ ^ to 111- '^ c CU O-' p-i £ =3 ^^ JJ ^J J J 3 2 Em ■ ^ '^ T? dSS§ cSSS s s Plot No. -H CI CO rt 1 1 -H C5 CO'* ^ CJ CO ^ ,— ( ^ r4^ ^ cooc 1 0000 0000 COOO ir. m f. ir. 1 1 ^_ CO CC CD t^ t-- r~- t^ GC 00 00 00 1 54 Soil Report No. 38: Supplement Table 10.— MT. MGRRLS FIELD: Series 500, 600, 700, 800, Summary of Crop Yields Average Annual Yields, 1913-1926 — Bushels or (tons) per acre Serial plot No. Soil treatment applied Potatoes 8 crops Alfalfa 19 crops Corn 6 crops Barley 6 crops Sweet clo- ver seed S crops Timothy- alsike 1 crop 1 89.8 137.8 143.5 141.1 (2.35) (3.0b) (3.77) (3.89) 68.0 70.6 74.0 74.7 37.8 49.3 55.4 55.3 3.83 4.28 3.24 3.10 (1.46) (2.01) (2.45) 2 M 3 ML 4 MLP (2.54) Crop Increases M over ML over M. . . MLPover ML. 48.0 ( .71) 2.6 11.5 .45 ( .55) 5.7 ■ ( .71) 3.4 6.1 -1.04 ( .44) - 2.4 ( .12) .7 - .1 - .14 ( .09) THE DIXON FIELD A summary of the results of the Dixon experiment field are presented here, inasmuch as the soil of this field is similar to some of that found in Ogle county. This field, which includes about 21 acres, is laid out into two general systems of plots, a major and a minor system. The results from the major system will be considered here. The rotation practiced has been wheat, corn, oats, and clover. The treatment of the plots and management of the cro'^s have been, for the most part, according to the general plan described above on page 46. The more important modifica- tion of this plan has been the discontinuance within the last few years of the applications of limestone, phosphate, and straw residues. Table 11.— DIXON FIELD: Series 100, 200, 300, 400, Summary of Crop Yields Average Annual Yields, 1912-1926 — Bushels or (tons) per acre Serial plot No. Soil treatment applied Corn 15 crops Oats 14 crops Wheat 11 crops Barley 1 crop Clover' 9 crops Soybeans 4 crops 1 36.3 55.6 59.7 62.3 42.6 50.5 56.4 57.7 61.1 41.3 49.0 61.7 65.5 67.3 54.4 58.7 62.6 65.1 64.6 52.0 20.3 26.9 31.0 34.2 21.7 24.8 28.0 32.9 33 . 7 20.0 43.3 46.4 55.2 58.3 49.5 53.8 54.5 59.0 56.9 45.4 (1.73) (2.44) (2.70) (2.82) (1.35) (1.47) (1.77) (2.04) (2.18) (1.89) (1.46) 2 M (1.78) 3 ML (1.92) 4 MLP (1.97) 5 6 R 11.8 13.5 7 RL 13.3 8 RLP 13.3 9 10 RLPK 14.6 (1.45) Crop Increases M over R over ML over M RL over R MLP over ML RLPover RL RLPK over RLP 19.3 7.9 4.1 5.9 2.6 1.3 3.4 12.7 4.3 3.8 3.9 1.8 2.5 - .5 6.6 3.1 4.1 3.2 3.2 4.9 .8 3.1 4.3 8.8 .7 3.1 4.5 - 2.1 ( .71) ( .12) ( .26) ( .30) ( .12) ( .27) ( .14) ( .32) 1.7 ( .14) • - -2 ( .05) 0.0 .7 'Including some seed crops evaluated in this summary as hay. Ogle County 55 Table 11 gives a summary of the results in terms of the average annual crop yields obtained since the plots have been under complete treatment. In considering these results, the most striking feature to be observed is the outstanding effect of farm manure. The average annual increase per acre in crop yields due to the use of manure alone amounts to nearly 20 bushels of corn, more than 12 bushels of oats, nearly 7 bushels of wheat, % of a ton of clover, and % of a ton of soybean hay. Organic manure in the form of crop residues has also produced increases in yields altho not to the extent of those produced by animal manure. Limestone in addition to organic manures has, with a single exception, effected more or less improvement, probably sufficient to cover the expense of application. Rock phosphate, as usual, shows up to best advantage used with residues on the wheat crop. The effect on other crops, however, has been such that the increases in yield are not sufficient to cover the cost of the application under existing market conditions. Altho potassium has produced an average increase of 3.5 bushels an acre in corn, the effects on other crops are such as to render its use unprofitable in growing these common field crops. THE VIENNA FIELD Inasmuch as Ogle county embraces in its Yellow Silt Loam and certain other soil types considerable land that is subject to destruction thru erosion or washing, an account of the experiments on the Vienna field should be of interest in this report. The Vienna field, located in Johnson county, is representative of the sloping erodible land so prevalent in that section of the state. Experiments were con- ducted nine years with the purpose of testing different methods of reclaiming this badly gullied land and preventing further erosion. The whole field with the exception of about three acres had been abandoned because so much of the surface soil had washed away and there were so many gullies as to render further cultivation of this land unprofitable. Experiments were started at once to reclaim this land, the different methods described below being used for this purpose. The field was divided into five sections. The sections designated as A, B, and C were divided into four plots each, and D into three plots. On section A, which included the steepest part of the area and contained many gullies, the land was built up into terraces at vertical intervals of five feet. Near the edge of each terrace a small ditch was placed so that the water could be carried to a natural outlet without much washing. On section B the so-called embankment method was used. By this method erosion is prevented by plowing up ridges sufficiently high so that on the occa- sion of a heavy rainfall, if the water breaks over, it will run over in a broad sheet rather than in narrow channels. At the steepest part of the slope hillside ditches were made for carrying away the run-off. Section C was washed badly but contained only small gullies. Here the attempt was made to prevent washing by incorporating organic matter in the 56 Soil Report No. 38: Supplement Fig. 4. — View op an Unimproved Hillside Just Over the Fence from the Field Shown in Fig. 5 soil and practicing deep contour plowing and contour planting. With two exceptions, about 8 loads of manure per acre were turned under each year for the corn crop. The land on section D was washed to about the same extent as that of sec- tion C. As a check on the different methods of reducing erosion, the land on section D was farmed in the most convenient way, without any special effort being made to prevent washing. Section E was badly eroded and gullied and no attempt was made to crop it other than to fill in the gullies with brush and to seed the land to grass. Sections A, B, C, and D Avere not entirely uniform ; some parts were washed more than others and portions of the lower-lying land had been affected by soil Fig. 5. -Corn Growing on Improved Hillside of the Vienna Experiment Field. Land Formerly Had Been Badly Erroded. Compare with Fig. 4 This Ogle County 57 Table 12. — VIENNA FIELD; Handling Hillside Land to Prevent Erosion Average Annual Yields, 1907-1915— Bushels or (tons) per acre Section Method Corn 7 crops Wheat 7 crops Clover 3 crops A Terrace 31.4 32.4 27.9 14.1 9.0 12.7 11.7 4.6 ( .68) B Embankments and hillside ditches ( .97) C Organic matter, deep contour plowing, and con- tour planting ( .80) D Check ( .21) material washed down from above. When the field was secured, the higher land liad a very low producing capacity. On many spots little or nothing would grow. Limestone was applied to the entire field at the rate of 2 tons per acre. Corn, cowpeas, wheat, and clover were grown in a four-year rotation on each section except D which had but three plots. Table 12 contains a summarized statement of the results obtained. These results indicate something of the possibilities in improving hillside land by protecting it from erosion. The average yield of corn from the pro- tected series (A, B, and C) was 30.6 bushels per acre, as against 14.1 bushels for series D; wheat yielded 11.1 bushels in comparison with 4.6 bushels; and clover .82 ton in comparison with .21 ton. A comparison of Figs. 4 and 5 will serve to indicate the possibility of im- proving this type of soil. THE OQUAWKA FIELD In 1913 the University established an experiment field on Dune Sand, Ter- race, in Henderson county, near the Mississippi river. This field is divided into six series of plots. Corn, soybean, wheat, sweet clover, and rye, with a catch crop of sweet clover seeded in the rye on the residues plots, are grown in rotation on five series, while the sixth series is devoted to alfalfa. When sweet clover seeded in the wheat fails, cowpeas are substituted. Table 13 indicates the kinds of treatment applied, the amounts of the ma- terials used being in accord with the standard practice, as explained on page 47. The data make apparent the remarkably beneficial action of limestone on this sand soil. Where limestone has been used in conjunction with crop residues, the yield of corn has been practically doubled. The limestone has also produced good crops of rye and fair crops of sweet clover and alfalfa. This land appears to be quite indifferent to treatment with rock phosphate. The analyses show, however, that the stock of phosphorus in this type of soil is not large, and it may develop as time goes on and the supply diminishes along with the production of good-sized crops, that the application of this element will become profitable. It is also quite possible that a more available form of phos- phate could be used to advantage on this very sandy soil. Altho the results show an increase of about 2 bushels of corn from the use of potassium salts, with ordinary prices this would not be a profitable treatment. 58 Soil Report No. 38: Supplement Table 13.— OQUAWKA FIELD: Summary of Crop Yields Average Annual Yields, 1915-1926 — Bushels or (tons) per acre Serial plot No. Soil treatment applied Corn Soybeans' Wheat Sweet clo- ver^ Rye 12 crops 12 crops 12 crops 8 crops 10 crops 20.2 ( .99) 8.7 0.0 12.1 25.3 (1.19) 12.0 0.0 13.7 33.4 (1.61) 16.1 1.03 24.7 33.9 (1.56) 16.4 1.05 23.4 19.7 ( .77) 10.7 12.7 21.2 ( .82) 12.2 0.0 12.9 37.2 (1.17) 15.1 1.41 24.0 37.0 (1.25) 15.6 1.28 24.1 39.2 (1.20) 14.9 1.49 26.0 18.6 ( .71) 9.6 0,0 10.3 Alfalfa 9 crops 9 10 M ML... MLP.. R RL... RLP. . RLPK .42) .92) 2.37) 2.45) .40) .45) 2.11) 2.10) 2.17) .29) Crop Increases M over . R over 0. ML over M. RL over R. . MLP over ML. RLP over RL . RLPK over RLP . 5.1 1.5 ( .20) ( .05) 3.3 1.5 0.0 1.6 .2 8.1 16.0 ( .42) ( .35) 4.1 2.9 1.03 1.41 11.0 11.1 .5 - .2 (-.05) ( .08) .3 .5 .02 - .13 - 1.3 .1 2.2 (-.05) - .07 .21 1.9 .50) .05) 1.45) 1.66) (- .08) .01) .07) 'Eleven regular crops, together with the extra crop described in the following footnote, aver- aged as 11 crops. Several crops which were harvested as seed are evaluated iu this summary as hay. ^Some hay evaluated as seed. In 1918 the sweet clover was killed by early cutting for a hay crop. Soybeans were seeded in July and the ensuing crop is included in the soybean average. The slight increases from the use of potassium appearing in the other crops are scarcely significant. A significant fact which the above summary does not bring out is that im- provement under favorable treatment has been progressive as evidenced by a very marked upward trend in production after the first few years. For example, it may be noted that the yield of corn under the limestone-residues treatment has been 37.2 bushels an acre as an average for the 12 crops since full treatment started, but if we take an average of the last five crops, the yield rises to 42.9 bushels. Likewise the wheat yield under this same treatment for the 11-year average is 15.1 bushels, but the average for the last five years is 22.3 bushels. Experience thus far shows rye to be better adapted to this land than wheat, and both alfalfa and sweet clover thrive better than soybeans. With these two legume crops thriving so well under this simple treatment, we have promise of great possibilities for the profitable culture of this land, which hitherto has been considered as practically worthless. THE MANITO FIELD The results secured on the Manito experiment field which was located on Deep Peat and which was in operation during the years 1902 to 1905, inclusive, are presented in Table 14. There were ten plots receiving the treatments indicated in the table. Where potassium was applied, the jdeld was three to four times as large as where Ogle County 59 Manure Yield: Nothing Manure and limestone Yield: 4.43 tons per acre Fig. 6. — Alfai^fa on the Oquawka Field These pictures show the possibility of improving this unproductive sandy land of the Oquawka field. Both plots were seeded alike to alfalfa. Where manure alone was applied, the crop was a total failure, but where limestone in addition to manure was applied, nearly 4^^ tons of alfalfa hay was obtained as the season's yield. nothing was applied. Where approximately equal money values of kainit and potassium ehlorid were applied, slightly greater yields were obtained with the potassium ehlorid, which, however, supplied about one-third more potassium than Table 14.— MANITO FIELD: Deep Peat Annual Crop Yields — Bushels per Acre Plot No. Soil treatment 1902 Corn 1902 Corn 1903 Soil treatment 1904 Corn 1904 Corn 1905 1 None 10.9 10.4 30.4 30.3 31.2 11.1 13.3 36.8 26.4 1 8.1 10.4 32.4 33.3 33.9 13.1 14.5 37.7 25.1 14.9 None 17.0 12.0 49.6 53.5 48.5 24.0 44.5 44.0 41.5 26.0 12.0- 2 None Kainit, 600 lbs Kainit, 600 lbs.. Acidulated bone, 350 lbs Potassium ehlorid, 200 lbs . . Sodium ehlorid, 700 lbs Sodium ehlorid, 700 lbs Kainit, 600 lbs Limestone, 4000 lbs 10 1 3 Limestone, 4000 lbs., Kainit, 1200 lbs 47.3 4 Kainit, 1200 lbs.. Steamed bone 395 lbs 47.6 5 6 7 8 Potassium ehlorid, 400 lbs. . None Kainit, 1200 lbs Kainit, 600 lbs Kainit, 300 lbs 52.7 22.1 47.3 46.0 9 Kainit, 300 lbs . . . . 32.9 10 None None 13.6 'Yield not recorded for 1902. 60 Soil Report No. 38: Supplement the kainit. However, either material furnished more potassium than was re- quired by the crops produced. The use of 700 pounds of sodium ehlorid (common salt) produced no appre- ciable increase over the best untreated plots, indicating that where potassium is itself actually deficient, salts of other elements cannot take its place. Applications of 2 tons per acre of ground limestone produced no increase in the corn crops, either when applied alone or in combination with kainit, either the first year or the second. Reducing the application of kainit from 600 to 300 pounds for each two- year period reduced the total yield of corn from 164.5 to 125.9 bushels. The two applications of 300 pounds of kainit (Plot 9) appear to be insufficient. List of Soil Reports Published 1 Clay, 1911 2 Moultrie, 1911 3 Hardin, 1912 4 Sangamon, 1912 5 LaSalle, 1913 6 Knox, 1913 7 McDonough, 1913 8 Bond, 1913 9 Lake, 1915 10 McLean, 1915 11 Pike, 1915 12 Winnebago, 1916 13 Kankakee, 1916 14 Tazewell, 1916 15 Edgar, 1917 16 DuPage, 1917 17 Kane, 1917 18 Champaign, 1918 19 Peoria, 1921 20 Bureau, 1921 21 McHenry, 1921 22 Iroquois, 1922 23 DeKalb, 1922 24 Adams, 1922 25 Livingston, 1923 26 Grundy, 1924 27 Hancock, 1924 28 Mason, 1924 29 Mercer, 1925 30 Johnson, 1925 31 Rock Island, 1925 32 Randolph, 1925 33 Saline, 1926 34 Marlon, 1926 35 Will, 1926 36 Woodford, 1927 37 Lee, 1927 38 Ogle, 1927 o o k 1 ^ HH <: w w OD 1-3 W Kl O 1— 1 O M ^ 1— ( TD Pi ^ o g P-H > Q ^ CI r o ^ o r q:5 X 3 o ^ o »— ^ § w 125 52 H H ^ CO H > H HH o !z! .^^-STilOO u 1^ 5 o o Q. — 5 S ?. §. o I =. m o m z o <^ po ^ O I-H < CO t— I H Hi 1—1 o r^ o I— I > Q l-H o n t- H a O o So W H H > H I— ( O o Hi o ti> m r~ (/I iJ o 1-i ^1 H S H L % CO jO q 1 T r > z o tn O -i.". 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