s 633 1(11 niiii FERTILIZERS: THEIR Source, Purchase #Use BY CARROLL B. SMITH SECOND EDITION COPYRIGHT DEPOSIT. >i ^ .:: -- .^ u O '^ rt o oJ -^^ V- ^ nJ /-. r- '^ T^ ^ -M '^ O r- '•" ^ ^ o 5r 5 O c; 111 = 1 '" oj :: jj ij .vh .H "^ 2-ii ■T3 ^^ r; pJD4_, FLRT1L1ZLR5: Their- Source, Purchase, and Use "Written for the Use of Farmers and Fruit Growers, With Special Reference to Citrus Culture. :: :: By CARROLL B. 5MITH SECOND LDITION Revised and Lnlarged REDLANDS. CALIFORNIA: CITROGRAPH BOOK PRESS 19 11 ■ A' COPYRIGHXED 1911 BY CARROLL B. SMITH ^C!.A305846 "'0!V TO THE READER. This work is designed expressly for those who are forced to use fertilizers and yet have not the time to investigate the subject as they would like to. It is intended to be brief and suggestive of thought to the reader rather than complete and final. Technicalities are avoided and illustrations simplified as much as possible. All the facts and deductions contained are based on the highest authorities on the sub- jects mentioned, and largely on the results of actual experience in California. The author hopes that the matter here given will aid the farmer to choose and purchase his fertilizers most wisely, and help him to get the best possible results from their use. There is no final authority in Nature. Every farmer's problems are his own and he must do his own thinking. The author has tried to present only the well established facts and general PRINCIPLES. A fuller knowledge of these, properly applied, will lead to better results and larger profits. CARROLL B. SMITH. Redlands, California. Note : This book has cross references throughout ; that is, when a number in parenthesis follows a sentence or paragraph it refers to some other para- graph or sentence having the same number, and treating of the same subject. Any phase of the Fertilizer question can thus be followed throughout the book. FERTILIZERS: Their Source, Purchase and Use SOMETHING ABOUT PLANTS. CIRCULATION. 1. The higher plants (Fruit and Forest trees) have a well defined circulatory system. Beginning with the absorption by the root , hairs of soil moisture, containing dissolved plant food, one set of tissue termed xylem carries this moisture or sap upward into the leaves and is there lost. In the leaf the sap is transformed or elaborated largelj^ by sun- light, according to the plant's nature and needs, and returned to the branches and trunk of the tree and its fruit, by another distinct set of tissue termed phloem. Both these sets of tissue are, roughly speaking, found in the ''Cambium" or sap layer of the bark. They are between the real bark and the wood of the tree. Wood is built up on one side and bark on the other. In a cross section of a limb or trunk of a tree these different tissues might be illus- trated, as in Fig. 1. The life of the tree is in the cambium. When we bud or graft it is cambium layer contact we want in both stock and scion. If the cambium is severed completely around the tree it dies. All of the soil derived plant foods enter the tree through its xylem tissue, found in the cambium layer. FERTILIZERS RESPIRATION. 2. Plants have a respiratory system. They ab- sorb oxj^gen and give off carbonic acid, mostly at night, but during the day more oxygen is given off and carbonic acid absorbed. The leaves and some of the green bark are the respiratory system. Carbon and oxygen thus enter the plant directly from the air as well as by water from the roots. Oii-tir £<^rl{ BA\KS oocL oLcL TitL FIGURE 1 TRANSPIRATION. 3. Plants give off water (Transpiration) at all times of day and night. The water escapes at cer- tain pores, called Stomata, of the leaf contained also in very young bark. Water carries the plant food into the plant by way of the roots. The plant foods, changed and elaborated, are retained in the tissue as new growth while the water passes off through the leaves as a vapor. When transpiration exceeds the supply from the roots the plant wilts. If the air is saturated with moisture, plants give off less, but FERTILIZERS 7 on hot days give off more. The leaves of fruit trees may be made large or small by an adequate or inad- equate supply of moisture. i';jThe^larger and healthier the leaves, the^more plant foodis^elaboratedj^and the better the growth and the crop. So the transpira- tion system and its healthy activities are very directly connected with the production of fruit. 4. Any serious or prolonged check to the process of transpiration necessitates a long time for full recovery, frequently several years. A severe wilting will show for a year, but a slight wilting usually fully recovers after watering. Thus the importance of a regular and sufficient supply of water is evident. Water is the common carrier of all the plant's food, whether the food is derived from the air or from the soil (13), the only positively known exceptions being the absorption of carbon and oxygen by respiration. The whole movement of water from the root hairs to the leaf and back to other parts of the plant and fruit, is confined to the cambium layer in which are contained the xylem (upward flow) and phloem (downward flow) tissue. LEAVES. 5. A good leaf is essential to the best results. Leaves put the plant in communication with sun- light, under which influence sap is changed and many products, incident and essential to growth, are manufactured. It is believed that all of the plant food brought into the tree by water, undergoes some change in the leaf (digestion) before it is finally added to the various tissue of the plant. If the leaf has been stunted or impaired by drought, frost or fire, it manufactures less of the products essential 8 FERTIUZERS to growth. Less water can come into it ; therefore, less water and less food enter the plant. Less sun- light can act on it, and all of the activities of the plant are so reduced that the result is a small crop of undersized fruit. Consequently, a good leaf is essential to the best results. BARK. 6. What has been said of the function of leaves is true, to some extent, of green bark. Old, corky bark may be regarded as the armor or shield to the cam- bium layer. But young, tender bark can carry on the process of respiration of carbon and oxygen, and of transpiration of moisture, and to that extent the transformation of the sap and plant food. Although these activities in bark are very limited, they are sufficient to continue the life of the tree should it ever become defoliated for purposes of transplanting or on account of disease or frost. Under the young bark's continued activity new leaves may start, until finally the plant renews its full health and vigor. ROOTS. 7. The distribution of plant food throughout the soil influences directly, and, with water, the entire development of the root. The absorptive power of the root is in the young, tender rootlets or fibres, by means of root hairs invisible to the eye. These root hairs are distributed along the length of the tender, growing fibre. The end of the fibre has a cap which protects it as it develops and crowds its way between the smallest soil particles. The very tips of roots and fibres cannot absorb moisture or food. FERTILIZERS 9 FIBROUS ROOTS. 8. If the soil is poor, the roots are very long and develop very few fibres and root hairs. But in a rich soil they are short and well branched, often forming a perfect mat of fibres. Under such fertile conditions the root hairs are more numerous and the plant's contact with the soil and its feeding powers are much greater. Consequently, roots develop where the food is. Fertilizers should be applied as deep as possible, so that root development w411 not be encouraged near the surface. (63) (79). SHALLOW WORK. 9. If the application of fertilizers and water is limited to the top foot the most of the fibres are de- veloped there, and deep ploughing and cultivation become questionable policy. Thick water conserv- ing mulch becomes impossible, (see frontispiece). This is the actual condition where impervious strata or ''hard pan" lies near the surface. DEEP WORK. 10. In open, deep soils where water can go down easily, the plant food is more widely distributed and likewise the fibrous roots. Here, deep work and a deep mulch are possible, and in case of water short- age, would be found a great advantage, as there is a better reserve supply in the sub-soil. APPLY FERTILIZER DEEPLY. 11. Present practice applies all fertilizer between the surface and the bottom of the plow furrow. This is unavoidable, even in open soils where the water is easily absorbed. Methods of effecting 10 FERTILIZERS deeper applications without serious root disturbance are unknown. As a result roots are encouraged near the surface, and this fact is the best argument advanced for the use of the most water soluble forms of fertilizer obtainable, as they are more widely dis- tributed by the movement of water. (77) (79). SOILS AND ROOTS. 12. The permeable character of the soil influences the root development, aside from the question of plant food. In clay or adcbe soils there is a limited root development and a resultant smaller tree. " Hard pans " near the surface have the same limit- ing influence. In such soils, more trees can be planted to the acre. Open, free loams or gravelly, sandy loams permit a larger root development and trees should be placed further apart. These are usually local ques- tions, but should be considered by the intending planter. The mechanical or physical nature of the soil should be known to a considerable depth. (20- 22). FERTILIZERS 11 SOMETHING ABOUT SOILS. 13. Of more th^ln seventy elements known to chemistry, fourteen have been found to be essential to plant life, Ten of these are soil derived, and four are derived from the air : Air Derived. Carbon Oxygen Hydrogen Nitrogen Soil Derived. Calcium Silicon Iron Magnesium Manganese Sulphur ^ Chlorine Sodium Potassium Phosphorus These fourteen elements, in var^dng portions, are peculiar to all plants so far as different species have been examined. 14. All soils, for convenience, may be considered as composed of various portions of: . Sand Rock Powder / Silt \ Clay Humus / Plant food \ > or simply ^ Clay Humus Sand is rock powder and may or may not contain silt. Clay is a chemical compound and a very im- portant element of soils, as it retains large amounts of moisture. If too abundant, the soil is intractable 12 FERTILIZERS and hard to manage, and bakes easily and while sand alone is too porous to retain moisture, the addition of a little clay with sand makes the proper balance for retaining moisture and for friabilit3^ 15. Humus, decayed organic matter, is absolutely essential as it is the source of the necessary nitrogen. It is a fundamental truth in connection with this sub- ject that there is no fertility without humus. It also influences favorably, as nothing else will, the soil's mechanical condition and moisture content, besides supplying essential plant foods. The humus which plants contribute to the soil not only furnishes all of the soil nitrogen, except that artificially added, but gives life to numerous forms of bacterial life, with which every healthy soil is teeming. We cannot discuss this subject here (86- 89), but it will suffice to say that, without the contribution made by plants to the soil, the micro- scopic forms of life could not exist and they are now regarded as essential to fertihty. Indeed, it is pos- sible to inoculate soils with beneficial bacteria, and improve their fertility. A soil may contain sand, clay and humus and yet lack some essential plantfood, hence the last division. But as a rule, sand, clay and humus in proper pro- portions will, for a time at least, supply all the requirements of plant life. The plant requires of the soil that it furnish the ten named soil derived elements, and the soil requires of the plant that it supply humus and such of the air derived elements as are necessary to its own health and fertility. Just what amounts of hydro- gen, oxygen, carbon and nitrogen are absorbed FERTILIZERS 1 3 directly from the air, and how much is contributed by plant life, is not known. But it is generally be- lieved that most of these elements as found in soils are derived from plants, either through the agency of beneficial bacteria or from the decay of vegetable tissue. 16. The character of vegetation changes with the soil. Pure clay soils support very little plant life, as there is no drainage, no ventilation and no 3aelding to root penetration. The right degree of porosity, due to the presence of sand and humus, allows the roots to enlarge rapidly which in turn nourishes a large plant. Hence the same species of plants v^ill vary in size and appearance according as the nature of the soil encourages or restricts their growth. A well developed root means a well developed plant and vice versa. If potassium or sodium or chlorine are in excess, the soil is alkaline and tolerated by certain classes of plants like the salt bushes, some of the mallows^ tussock grass, etc. Peat lands, bogs and meadows have a characteris- tic vegetation. Peat may contain as high as 80 j^^ humus or decayed organic matter. Here, nitrogen is naturally in excess and moisture plenty, so that the growth is vigorous and succulent. Tall grasses, and willows thrive here. The v^^ell drained ''mesa" of the arid west, sup- ports another variety of vegetation and a dense forest cover or leaf mould, still another, according to their moisture holding powers. The various com- binations of sand, clay, humus and plant food are almost infinite. 14 FERTILIZERS 17. Soils vary in chemical composition according to depth. The surface foot or two feet usually con- tains the bulk of the nitrogen, due to the fact that the nitrates are water soluble and the evaporation of moisture at the surface leaves the nitrates and all soluble plant foods there for the benefit of young plants whose roots have not gone deep. Young plants must grow first, and nitrogen produces growth. As the plant matures, its roots penetrate lower into the region where the nitrogen is scarce and where the phosphates, silicon, lime and insoluble elements are more evenly distributed. There, fruit production and maturing of tissue take place. During the time growth is vigorous, fruit produc- tion is limited or impossible even in the case of mature trees when artificialh^ forced to an abnor- mally vigorous growth. 18. While nitrogen is the chief element of grow^th, other elements of the soil favor fruit production. Phosphorus is definitely known to be one of these. (70). If the fruit producing elements of the soil w^ere abundant on the surface, and nitrogen, relatively deficient there, then fruit trees w^ould be heavily laden before they were taken from the nursery. There is abundant evidence of order and design in the methods of nature. "First the blade, then the ear, then the full corn on the ear," and the soil is so arranged as to effect the order. 19. It is interesting to note briefly that the func- tion of potassium is to mature the growth that nitrogen produces. Where nitrogen is in excess of potassium, as in bogs and peat lands, the growth is soft and watery, whereas if potash is abundant and FERTILIZERS 1 5 the nitrogen supply less, the growth is hard and firm. As illustration : note the strength of chap- arral wood, compared with marsh land growth. Nitrogen is deficient (comparatively) where the chap- arral grows and the mineral or soil derived elements, including potassium, relatively abundant. In a word, potassium gives starch or stiffness to the plant. Young peppers, acacias and eucalyptus trees bend frequently to the ground because their roots are in the surface soil, feeding on the excess of nitrogen and water. Older trees with deeper roots have not this tendency. (71). Sulphur, iron, calcium and silicon also perform special parts in the building of plant tissue, but a discussion of these would extend our subject unneces- sarily; ThcA^ are not "essential" plant foods. (23). PHYSICAL CONDITIONS. 20. In California the mechanical or physical con- dition of the soil is of greater importance than the chemical composition. Especially is this true of cit- rus culture, where irrigation and cultivation are so frequent and thorough. The first sign of trouble is usually a slight j^ellow color of the foliage and is usually traceable to loss of humus and its conse- quent nitrogen. Yet the cause may be due to the roots entering a "hard pan" or coarse gravelly strata, less favorable to growth. (99). In any event the soil's mechanical condition should be known to a depth of at least five feet, and deeper if possible. The loss of humus so changes the soil's condition that the trees cannot derive the benefit of the water, the cultivation or the labor gives to it, and the first sign is the loss of the healthy green color. 16 FERTILIZERS Applications of nitrate are helpful but not lasting unless applied in organic forms, capable of making humus. (86) (96). DRAINAGE. 21. Citrus soils must be well drained. The top soil may be free from gravel for a considerable depth as long as it does not hold free water. The "mesa" or ''bench" soils of California, usually situated near the foot hills, are ideal in this regard. Figure 2 is a photograph of a stream bank, running through a "mesa." The top soil, free from rock, is here about 5 feet deep, below which there is excellent drainage. HARD PANS. 22. Occasionally the best situation and soil for fruit culture is underlaid at a few feet with an im- pervious strata, so that orchards soon show lack of vigor. These "hard pans" may be at the very sur- face or at any depth below. Blasting with powder or dynamite to break up the fixed condition is effec- tive, but must be repeated from time to time. Per- haps the best remed3^ where water is sufficient, is to prepare it long before planting trees, by raising a one or two year old stand of alfalfa, the roots of which penetrate hard soils to a considerable depth. Though the orchard is already established, alfalfa might be grown in alternate spaces between the tree rows for two years, then ploughed under and the remaining spaces planted for the next two years. "Hard pans" are usually deficient in nitrogen, but may be well supplied with the other plant foods, and especially with lime and iron. The latter gives a very noticeable deep red tint to the orange. FIGURE 2 FERTILIZERS 1 7 ESSENTIAL PLANT FOOD. 23. Each of the three plant foods, nitrogen, phos- phoric acid and potash, are called essential ingredi- ents in fertilizers, as the3' are the elements first exhausted from the soil by plants. There are eleven other elements just as essential to perfect plant growth as these three, but the soil never becomes depleted of them, and it is not necessary to supply them, except in rare cases. Sometimes lime is sup- plied to the soil, though not regularly, to set free nitrogen, phosphoric acid and potash, when they are known to be in the soil in insoluble condition and large amounts. But, as lime adds no necessary ingredient, its continued use alone wall exhaust a soil. If a soil is known to lack iron, this may be added to make green foliage and to deepen the color of oranges. If a soil becomes unproductive under conditions of good tillage and water, it is usually because one or more of the essential plant foods has become ex- hausted. Hence commercial fertilizers have come to be composed of various amounts and forms of nitro- gen, phosphoric acid and potash. Commercial fer- tilizers are simply concentrated forms of plant food. A good top soil contains every element essential to plant growth and is a fertilizer, but it is not suffi- ciently concentrated to pay for handling and trans- portation. 24. Each of the three plant foods, nitrogen, phos- phoric acid and potash, have their respective market values for each 1 per cent., or unit, of 20 pounds to the ton. If a ton of fertilizer contains 3 per cent, of an element that means 60 pounds. The purchaser 18 FERTILIZERS will have to know in addition to the amount, the market value and the source of the nitrogen, phos- phoric acid and potash, before he can determine the value of a ton of certain analysis. The source is very important, because the most available forms have the highest market value. Without this know- ledge, a certain brand may sell for $40 a ton and another worth onlj- one-half its value ($20 per ton) may sell more readily for $38. 25. Each of the three essential plant foods has its special part to do in the building of the plant. One cannot do the work of the other. As an illus- tration: Nitrogen in the absence of potash may produce a luxuriant and rapid growth but it will be weak, and broken dov/n by the first wind ; add potash and that same succulent, weak growth will be matured and have strength enough to carry its load of fruit. Potash alone will not produce the growth, but will mature it. Both nitrogen and potash have manv other functions to perform. (69), (71). Phosphoric acid, or phosphorus, must be present in order that the plant may assimilate its nitrogen. The process (osmosis) by which nutrients pass through the plant from cell to cell is facilitated by the presence of phosphoric acid. Phosphorus is nec- essary for the seed's embryo development and for the formation of chlorophyl (the green coloring matter of plants). (70). Thus, while the essential plant foods each have many independent functions to perform, they are mutually dependent upon each other, and mutually helpful in the building of the plant tissue = FERTILIZERS 19 The condition in the soil may be such that the purchase of only one fertilizing element is necessary, and since the source of nitrogen and phosphoric acid and their functions are so many and varied, the question, ''What fertilizer to use," and **Howto purchase it most economically," is of vital interest to the farmer and one difficult to solve. SOURCE OF FERTILIZERS. THE SOURCE OF NITROGEN. 26. Nitrogen may be obtained from these sources : Air, ammonia, nitrates, and animal matter. In certain forms of minimal matter, such as hoofs, horns, coarse bone, leather and wool waste, the nitrogen becomes available too slowly to be of much value. But as green manure, ammonia, nitrates, blood, fine bone, tankage, or blood and bone, fish and finely ground and screened guano, the nitrogen is in good form and soon becomes available. 27. As these forms require different lengths of time to become available, judgment must be used in their application. Nitrate of soda and sulphate of ammonia dissolve almost immediately in water, so the full amount of a year's supply should not be applied at once, as some will be sure to be lost in waste water. Blood and bone, as a source of nitro- gen and phosphoric acid, would be a better combi- nation than nitrate and bone. Blood and fish re- quire more time to become available than nitrates, and bone, a longer time than blood. (43) 20 FERTILIZERS The most valuable sources of organic nitrogen, from the standpoints of uniformity in composition, richness in the constituent, and availability, are dried blood, dried meat, and concentrated tankage, fish and animal, which are produced in large quantities in slaughter houses and fish canneries. 28. The most concentrated form of nitrogen is ammonium sulphate, containing about 19X or 24^% of ammonia. Nitrate of soda contains as high as 16% nitrogen, blood 14^^, hoof and horn meal, 14%, slaughter house tankage from 5% to 10%, raw bone 'SV2%, bat guano S% to 20%, sea fowl guano 12%. There are numerous other sources of nitrogen, but the above are those most generally used. The contents as given are in terms of nitrogen and approximately the maximum. TtrfrU tcomJ}