————— = SSS SSS Se Book Vy ; Copyright N°” 19.27 COPYRIGHT DEPOSIT: fh apn = ot ey \ MPA Ta RoR iy LA OF iM a On Te Vit Mi : i i r iy Nae ba TAs ' eee Se BN i none an ry : ' xf ~ 2) iti An FERTILIZERS FERTILIZERS THE SOURCE, CHARACTER AND COMPOSITION OF NATURAL, HOME-MADE AND MANUFACTURED FERTILIZERS; AND SUGGESTIONS AS TO THEIR USH FOR DIFFERENT CROPS AND CONDITIONS BY EDWARD B. VOORHEES, A. M. Director of the New Jersey Agricultural Experiment Stations, and Professor of Agriculture in Rutgers Colleve NINTH EDITION Neto ork THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., Lrp. 1907 AU rights reserved 4 il : ‘ Nw! 189¢ | ar \ fy Oe 4) se No \ { Le Z CopyRiIcHT 1898 8y EDWARD B. VOORHEES Set up and electrotyped November, 1898 Reprinted with corrections January, 1900 January and February, 1902, February, 1903 August, 1904, August, 1905, January, 1907 March, 1907 Mount Pleasant Press J. Horace McFArRLAND COMPANY HARRISBURG * PENNSYLVANIA PREFACE THERE is no question as to the desirability of the use of commercial fertilizers on most farms, though the methods now generally practiced are such as to indicate the very great need of a better under- standing of what the functions of a fertilizer are, of the terms used to express their composition and value, of the kind that shall be used, and the time and method of application for the different crops under the varying conditions that exist, In the preparation of this book, therefore, it has been the aim of the author to point out the under- lying principles and to discuss, in the light of our present knowledge of the subject, some of the important problems connected with the use of fer- tilizer materials. The subject is a large one when considered in all its bearings, and much must nec- essarily be omitted in a book intended for the general reader as well as the student. The author appreciates keenly his _ limitations, owing to the lack of definite knowledge on many vital points; yet it seems that at this time, when (v) sal PREF ACH the investigations of the experiment stations are beginning to be regarded as important educational factors, and when these institutions are more than ever prepared to study the fundamental principles which underlie the various processes involved in plant nutrition, the practical man should have a clear understanding of what is now known, in order that he may be prepared to accept and use that better knowledge which will undoubtedly be _ pro- vided for him in the near future. Bevo New Brunswicx, N. J., September 20, 1898. CONTENTS CHAPTER I THE NATURAL FERTILITY OF THE SOIL, AND SOURCES OF Loss OF THE ELEMENTS OF FERTILITY ......---..-- H Soin FEeRTILITy—Chemical elements needed in plant growth—Fertility as influenced by water, climate and season—The influence of physical character of soil— Location of soil qualifies the term “fertility ” — Practical fertility is usable potential fertility ...................... Wuat BrecoMES OF OUR FERTILITY ?......... Sy atalsiotecsroier sions ielsve Sources oF NaTuRAL Loss oF NITROGEN—Importance of careful culture—Loss of nitrogen by drainage— Escape of nitrogen into the atmosphere ................2--0- Biaretersiekie THE Naturau Loss oF THE MINERAL ELEMENTS— Losses due to mechanical Means)rs-ncciec cee cincier clas ccinicleleralecerte ARTIFICIAL LOSSES OF FERTILITY—A comparison of the prices received for the fertility elements in different crops—Fertility content of cereals and vegetables—Irra- tional farm practice—Losses in manures.............. seals CHAPTER II THE FUNCTION OF MANURES AND FERTILIZERS, AND THE NEED OF ARTIFICIAL FERTILIZERS ..-........... eitlets THE ESSENTIAL ELEMENTS OF FERTILIZERS ....22.ccccecees NaTURAL MANURES AND ARTIFICIAL FERTILIZERS ....00.-00: (vii) PAGES 1-20 2-7 1-8 14-20 21-37 Vill CONTENTS PAGES DIRECT AND INDIRECT EFFECT OF MANURES.........2000---: 23 UNAVAILABLE AND AVAILABLE PLANT-FOOD ......22..-220-- 24-26 DANGER OF Loss FROM THE USE OF SOLUBLE PLANT-FOOD.. 26 THE USEFULNESS OF A FERTILIZER CONSTITUENT DOES NOT DEPEND Upon ITs ORIGINAL SOURCE .....-...-22..2000-- 27 USE OF FERTILIZERS........ atatatatelotaiaielalovaletoetotelatersimeters tel Gleia leer 28, 29 THe Neep OF ARTIFICIAL FERTILIZERS—The cost of produc- tion per unit of income is increased—A greater demand for special crops— Farm manures are inadequate— The growing importance Of fruit-CrowiN Ss). oncci-ial-cimeicie iaie\elo cle eieiese c= ieee 30-35 WILL, IT¥PAVATOMUSE WER TUGIZERS # icros celoleisictolelstetecie cle taisierelat= 35-37 CHAPTER III NITROGENOUS FERTILIZERS ..... a aieicbeie teeteis tee ears syvereela MAO ORENG Wauat Is MEANT BY Form OF NITROGEN ? .........-00.0e00es 39 DRIED PE LOOD! teas aio.clcle'es}-le oiatale Sauacse afctalalefotadeietcve-cissiateioiete voir 40, 41 DrigepD Meat OR MEAL, AZOTIN, AMMONITE, OR ANIMAL VIVAITT ENTE 2 aes crore aicVoiehoieis’ atsre spe’els els elevate tone) ainteletaiateletsteintelaieys ss sjaleta,ele 41 LOO RMIER AI. e\sra- 2,000 ‘* ne 170 ‘‘ total plant-food With a guaranteed composition of : Nitrogen. . ... 5) eis eau) Sige ME ee, FRAN Ue 1.5 % PHOaphOoOric "ACIG oo) 664) -A oon ase sas 4.5 % Potashe(aetual)): = oink een eae NO eee DI ae ForMuLA No. 4 ia 60 lbs. nitrogen 9, Mankave.) oo) le 200) bs. furnishing |) 5 een OrinGanet BING) A318, eee S00. ne 100 ‘‘ potash (actual) Fotali. 0.2%. 25000: ay 340 ‘‘ total plant-food 144 FERTILIZERS With a guaranteed composition of : INitrogeny S20 tone eae ee eee tenteeee 3% Phosphoricyacide sce i een 9 % Potash fis tir Oey eM edo eae ee Sees EONS Formula No. 1 shows a high-grade product, both in respect to quality of plant-food and concentration, while No. 2 is high-grade only in respect to quality. In order that the plant-food may be distributed throughout a ton of material, it is necessary to add what is called “make-weight,” or a diluent. These usu- ally consist of substances that possess no direct fer- tilizing value. High-grade mixtures cannot be made from low-grade materials, and low-grade mixtures eannot be made from high-grade materials without adding “make-weight.” The advantages of high- grade products are concentration and high quality of plant-food. It will be observed that formula No. 1 contains nearly twice as much plant-food as No. 2, or, in other words, it will require about two tons of a fer- tilizer made according to formula No. 2 to secure the same total amount of plant-food as is contained in one ton of No. 1. Now, the material in No. 2, other than the actual plant-food, is of no direct ferti- lizing value,—it is of no more value as a fertilizer than the soil to which it is applied,—but the actual cost of the constituents is considerably in- creased, because the expenses of handling, bagging and shipping are just double what they would be for No. 1. DISCUSSION OF FORMULAS 145 Formula No. 3 illustrates a low-grade fertilizer in the sense that it contains the poorer forms of the con- stituents, and furnishes a comparatively small total amount of plant-food. The nitrogen is all in the organic form, and is derived from tankage, which, while not the poorest, is poorer than other forms of organic nitrogen. The phosphoric acid is also in organic combination, and, while useful under many conditions, is less useful for certain other conditions than the soluble in Nos. 1 and 2. The potash, while soluble, is derived from kainit, which, because of its large content of chlorin, is regarded as less desirable for certain crops than the more concentrated materials, muriate, or the high-grade sulfate, which is free from chlorids. It would require more than 2% tons of a mixture made according to this formula to furnish as much total plant-food as would be contained in a mixture made according to formula No. 1, besides the disadvantage of the lower quality of the constituents. Formula No. 4 illustrates a mixture which, while rich in total constituents, is not high-grade in its quality. All of these considerations should, therefore, be carefully observed in the purchase of mixtures, or even in the purchase of raw materials for home mixtures, and the analysis, if properly made, will give positive evidence on these points. The expensiveness of low-grade fertilizers, as repre- sented by formulas Nos. 2 and 3, is not fully appre- ciated by the purchaser in all cases. He does not stop to think that it is quite as expensive to handle the J 146 FERTILIZERS material which contains no plant-food as it is to handle material which is rich in plant-food. The Cost of Handling “ Make-weight” A comparison of the advantages of low-grade and high-grade mixtures in this sense of total quantity of plant-food may be illustrated as follows : It has been shown by continued studies at the New Jersey Experiment Station that the charges of the manufacturers and dealers for mixing, bagging, ship- ping and other expenses are, on the average, $8.50 per ton; and also that the average manufactured fertilizer contains about three hundred pounds of actual fer- tilizing constituents per ton. <. 20/200 >G 11450) =— 2 80 Phosphorie acid, soluble. . .8X20=160 K 45 = 7 20 ey c> mereviertedman. ll >< 20— 20 x Nitroeen f 4X 50 in fine. <20= 40 X 13.5 $5 40 l 4X 50= 2in coarse. *K 20—= 40 KX 10.0 = 400 Phosphoric (20 K 50=—10infine. > 20—200 K 4.0 = 800 acid . (20 X 5010 incoarse. XK 20=200 K 3.5 = 700 Total estimated value per ton ..., ..... . $24 40 164 FERTILIZERS The first column of figures shows the per cent, or pounds per hundred, of the constituents, which is multiplied by the percentage of fineness, which gives the percentage or pounds per hundred of fine or coarse in the third column. The calculation is then finished as in the ease of complete fertilizers. THE UNIFORMITY OF MANUFACTURED BRANDS Another point which consumers of fertilizers are interested in is the reliability of the various brands. That is, they desire to know whether a brand that shows good forms of nitrogen, of phosphoric acid, and of potash in one year may be depended upon to fur- nish approximately the same the following year, or whether the manufacturers change their formulas from year to year to conform to the relative cost of the different materials: that is, whether when nitrogen is relatively expensive and phosphoric acid is rela- tively cheap, they introduce a larger proportion of phosphorie acid and a smaller percentage of nitrogen; whether when organic nitrogen is cheap and nitrate and ammonia nitrogen are dear, they change the pro- portions of these to correspond with the difference in price, in order to retain the same selling price. This is an important point, since after a certain brand has been shown to be better suited than another to their conditions of soil, to change the formula, both in reference to the character and pro- portions, may mean to the purchaser the difference between profit and loss. UNIFORMITY OF MANUFACTURED BRANDS 165 Evidence on this point ean be obtained from the reports showing the results of the analyses of the dif- ferent brands from year to year, and a careful study of these shows that genuine manufacturers of fertilizers,—those who make it their sole business, rather than a side issue or an adjunct to another busi- ness,—ean be fully depended upon in this respect. They know that the farmer’s interest is their interest, and that their sales will depend, other things being equal, upon the increased crop results that the farmer secures; that the permanency and success of their business will depend upon the successful and profitable use of their product; and that they cannot afford to and do not change their formulas from year to year, either in proportion or quality of constituents, to cor- respond with the changes in price of the materials. Their brands can be depended upon to furnish prac- tically the same amount, kind and proportion of plant-food from year to year. The value of a fertilizer depends upon the kind, quality and form of plant-food, as shown by the analysis. Value does not depend upon who the manu- facturer is, or what the statements may be concerning the usefulness of special manipulation, nor to any great extent upon special formulas, unless the farmer has positive knowledge of the character of his own conditions. Formulas derived both in kind and pro- portion from the same materials will do equally well under the same conditions. So far as the matter has been investigated, there is no specific virtue added by what is claimed to be the “blending” of the materials. 166 FERTILIZERS In the whole matter of the purchase of fertilizers, no guide, however good, can take the place of intel- ligence on the part of the purchaser. This intelli- gence must be exercised in the selection of forms of plant-food, in the preparation of formulas, in the interpretation of guarantees and of commercial values, and in the method of using the fertilizer. CHAPTER IX METHODS OF USE OF FERTILIZERS THE primary object in the use of a commercial fer- tilizer is to receive a profit from the increase in the yield of crops from the land to which it is applied; and this may be derived either from the immediate crop, or from the larger yield of a number of crops. That the greatest immediate or prospective profit may be gained, a wide knowledge of conditions which have either a direct or indirect bearing upon the result is essential. CONDITIONS WHICH MODIFY THE USEFULNESS OF FERTILIZERS In fact, the controlling ccenditions surrounding the matter are so numerous and so various that it is im- possible, with our present knowledge, to lay down positive rules for our guidance. At best, only sug- gestions can be offered. We may possess a full knowledge of both the kind and form of existing fertilizer supplies, their cost and the action under known conditions of the constituents contained in each, as well as their maximum capability for increasing the crop, but together with this knowl- edge, it is essential that we should know how these (167). 168 FERTILIZERS facts and principles must be applied to each individual crop, soil and condition, and yet even with this, abso- lute certainty of profit is not guaranteed. A few of the more important conditions which control the profitable use of fertilizers are, therefore, briefly dis- cussed, in order to arrive at a better understanding of the practical suggestions and concrete examples given in subsequent chapters. Derivation of Soil a Guide as to its Possible Deficiencies The first consideration is the soil itself, and its influence. It is well known that a wide difference exists in soils, both in reference to their chemical character or composition, and to their physical proper- ties, each having a direct influence in determining the effect of any specific application of fertilizers. These differences in soils are due to changes which were wrought in the surface of the earth during its forma- tion, and which are continuing in a small way at the present time. It is believed that the original earth crust contained all the minerals now found in it, but that in the beginning they were distributed more uni- fromly throughout its mass, and that the soils as they exist at the present time, and as a result of the direct disintegration of the original rock, represent a very” small area of the earth’s surface. They are not now constant, but variable in their character. The various changes that have taken place during geologic time have resulted in the breaking up of the original rocks, SOILS DIFFER IN CHEMICAL COMPOSITION 169 a part having been separated mechanically and being represented by various sizes of particles, and a part rendered soluble. The fragments and the soluble por- tions thus separated have not been deposited again in the same proportions as they existed in the original rock, which has caused a very wide variation in the chemical composition of the different soil deposits. The prozess and its results may be shown at the present time in the wearing away of rocks. The harder, sandy particles separate mechanically, and because of the difference in the size of the particles, the coarser are deposited as gravel or sand, in one place, and the finer particles are deposited in another, making the clay. The lime enters partly into solution and is de- posited in another place, and so on, thus giving us sandy soils, clayey soils and limy soils, all differing from each other in their amount and proportion of the essential fertilizing constituents, as well as in their physical qualities,—the sandy and gravelly making the poorest soils because the particles consist very largely of quartz, and the remainder being poor in phosphoric acid or potash. The clay soils are frequently rich in minerals containing potash, and poor in those con- taining lime and phosphoric acid; and the limestone soils are poor in potash and rich in lime, and fre- quently in phosphates. In addition to these soils, there are those that are made up largely of vegetable matter, due to the accumulation of decaying growths. These are frequently rich in nitrogen and poor in all of the essential mineral constituents. Hence it is that in the use of a commercial fertilizer, 170 FERTILIZERS at least for certain crops, a knowledge of the nature of soils in respect to the possible deficient element is important, in order that those which exist in abun- dance may not be added to, but that they may be sup- plemented by such an abundance of the deficient ele- ments as to permit the acquirement by the crops of those necessary for a maximum growth. As a rule, potash is a very essential constituent of manures for sandy soils, not only because all crops require potash, but because they require it in relatively large amounts, and because in sandy soils it is liable to exist in minimum amounts. Potash fertilization, therefore, is especially useful on sandy soils. On the other hand, in clay soils, which, as a rule, contain a very con- siderable proportion of potash as compared with sandy soils, the deficient element may be either phosphoric acid or lime; and if these are supplied in abundance, the plant will be able to secure the necessary potash. In a limy soil, the lime and phosphoric acid, and per- haps the potash, may be in sufficient abundance to cause a normal growth of plant, yet the nitrogen may be so deficient as to prevent a normal growth. Physical Imperfections of Sandy Sotls If it were possible to distinctly classify soils in respect to their lack of one or more of the essential constituents, it would be an easy matter to formulate rules for our guidance in the fertilization of these soils; but such is not the case. Even sandy soils vary widely in their chemical composition, as well as in SOILS DIFFER IN PHYSICAL CHARACTER 171 their mechanical or physical properties, and certain of them possess such a physical character as to make it impossible to grow maximum crops even though the essential elements are all supplied in sufficient abundance. The constituent particles are too coarse, and thus make the soils so open and porous that they too freely admit the air, water and warmth, and thus results a very rapid drying and heating of the soil, with a premature ripening and burning of the crops. The phosphates or the potash compounds ap- plied are not readily fixed, and suffer an immediate loss as soon as rain falls in such amounts as to cause a leaching from them. Physical Imperfections of Clay Soils In elay soils, the physical conditions are quite the reverse. All clay soils do not have the same general composition, and they differ widely in their physical qualities. Certain of them possess a reasonably good texture, and permit the absorption of the food applied, as well as its gradual distribution throughout the mass by the percolation of the water through them; while certain others are so compact, owing to the finely divided particles, that even though they were abundantly supplied with all or the necessary mineral constituents, profitable crops could not be grown because the roots could not readily penetrate, and because the water falling upon the land would not readily pass through, but remain upon the surface. In the ease of soils with an abundance of lime, 172 FERTILIZERS physical qualities also exercise a very considerable influence, even though there is a sufficient supply of all of the fertility elements. Certain of them are too cold, others are too dry, and the mechanical condition is such as to prevent the proper and uniform growth of plants. It must be remembered, then, that only gen- eral rules apply in the use of fertilizers upon soils of the different classes, and that they are modified by both the chemical composition and the mechanical con- dition of the soils. The best use of a fertilizer,—that is, the greatest proportionate return of plant-food in the crop, all things considered,—is obtained from its ap- plication upon soils that possess “condition,” or that are well cultivated or managed. Full returns eannot be expected when they are applied upon soils that are too wet or too dry, too porous or too compact, or too coarse or too fine. It is important that even the best soils should be properly prepared, and it is infinitely more important that those which possess poor mechan- ical condition should be improved in this respect, before large expenditures are made for fertilizers. The Influence of Previous Treatment and Cropping In the next place, the previous treatment and cropping of soils should guide in the use of fer- tilizers, since soils of the same natural character, located equally well, will not always show the same results from the application of fertilizers, because in the one case the cropping has been such as to result in the rapid exhaustion of one, rather than the three INFLUENCE OF PREVIOUS CROPPING 173 specific fertilizer elements; while in the other, the cropping may have been quite as severe, but has been helpful because judicious rotations have been used and improved methods practiced. It may be that in the one case, there may have been a continuous cropping of wheat, for example, and only the grain sold from the farm, in which case there would be a much more rapid exhaustion of the nitrogen and _ phosphoric acid than of the potash; and if this continuous wheat-cropping has been continued for a long time, an application of the phosphates only may result in quite as large an increase in erop as if both phos- phates and potash salts were applied, because the potash exhaustion has been less rapid than that of the phosphoric acid, and the addition of potash would simply add to the probably abundant quantities already there. On the other hand, if the cropping has been timothy hay, the removal of the potash would have been greatly in excess of the phosphoric acid, and consequently a fertilization with a greater proportion of potash, or even this element alone, of the minerals, may result in quite as large returns as if the fertilization had consisted of both phosphoric acid and potash. In fact, if the land had been cropped continuously with tobacco, cotton, potatoes, or other crop, there is likely to be a much larger removal proportionately of some one element, rather than proportionate amounts of all. This practice results in a disproportionate removal of the constitu- ents, and in order to bring the land back to its capacity for maximum production, or to equalize 174 FERTILIZERS matters in this respect, it is necessary to add to the soil the constituents removed in amounts in excess of the others. On the other hand, the cropping may have been such as to be fully as exhaustive in the sense that the total quantity of constituents removed is quite as great, though since they are removed in more uniform proportions, the period of profitable cropping is extended, and the fertility needed includes all the essential elements, rather than one or two. That is, the grain, hay and potatoes may have been grown in rotation, each removing one or the other in greater proportion, but because they differ with each crop, no one is exhausted before the other; and thus when the land reaches the time when it would no longer profitably grow those crops, an application then of all of the constituent elements would result in a greater and more profitable increase in crop than if the fertilizer contained one constituent only. The previous treatment and cropping of soils, therefore, is an important guide in determining the most economical method of fertilization. Furthermore, in this matter of cropping as a guide to possible need of fertilization, it must be remem- bered that a continuous one-crop practice is more productive of total loss of constituents than a prac- tice which includes such renovating crops as clover, or one which permits of a more constant occupation of the land, since in the former, the introduction of clover reduces the need for nitrogen fertilization, and in the latter, the vegetable matter is not so rapidly used up, and the loss of mineral constituents by INFLUENCE OF CHARACTER OF CROP 175 mechanical and other means is very much reduced, because of the constant occupation of the land. The Influence of Character of Crop The financial result from the application of fer- tilizers is also influenced in a very large degree by the character of the crop itself, whether the value of an increase in crop as great as can be expected from a definite application is high or low; and on this basis, crops may be classified into two general groups: first, those which possess a high fertility, and which, as a rule, possess a relatively low commercial value; and second, those which possess a low fertility value and a relatively high commercial value. In the first class are included the cereal and forage crops, as corn, oats, wheat, hay, buckwheat, cotton and tobacco, and in the second are included the various vegetable and fruit crops. This classification, and its importance, may be illustrated by the following examples : A ton of wheat, at $1 per bushel, will bring $33.33. Its sale removes from the farm 38 pounds of nitrogen, 19 of phosphoric acid, and 18 of potash. At prevailing prices for these constituents, it would cost $6.50 to return them to the farm. A ton of asparagus shoots, at 10 cents per pound bunch, will bring $200. Its sale removes from the farm 6 pounds of nitrogen, 2 of phosphoric acid and 6 of potash, which could be returned for but little more than $1. 176 FERTILIZERS A ton of timothy hay will bring $10. Its sale removes from the farm 18 pounds of nitrogen, 7 of phosphoric acid and 28 of potash, amounts that would cost $4. A ton of apples will bring in an ordinary season $20. It removes less than 3 pounds of nitrogen, 1 of phosphoric acid and 4 of potash, which would cost less than 60 cents to return to the land. It is thus shown that crops like wheat and hay possess a relatively low commercial value, and yet carry away, when sold, a very considerable amount of the fertilizing constituents, while vegetables and fruits, as illustrated by the asparagus and the apples, have a high commercial or market value, and carry away but minimum amounts of the fertilizing con- stituents. This distinctive character of crops, while not an absolute guide as to the profits that may be obtained from the use of fertilizers,—since the cost of production varies widely for each class,—is instruc- tive in showing that those of a low commercial value are more exhaustive than the other class, or those of a high market value, and is certainly suggestive, pointing out the necessity for judgment in the ap- plication of fertilizers that shall be made in the ease of crops of the different groups. The Kind of Farming, Whether “ Extensive or Intensive” Another very important consideration, and one which exercises an influence, is whether the farming engaged in is “extensive” in its character, or “intensive;” CHARACTERISTICS OF GROWTH 177 whether the purpose or idea is to simply supplement the stores of plant-food in the soil, or whether the object is to ensure an abundance of all forms of constituents under all reasonable conditions, in order that a maximum production may be secured. PLANTS VARY IN THEIR POWER OF ACQUIRING FOOD In the next place, the character or feeding capacity of the plant and its season of growth should be con- sidered, that systematic methods may be adopted, and thus not only that waste of fertilizing materials may be avoided, but that the applications may be made at such times and in such amounts as will, other things being equal, promote the greatest increase per unit of applied food. While each plant possesses individual characteristics which distinguish it from all others, for our purpose they may again be classified into general groups which possess somewhat similar characteristics, particularly as to their method and time of growth and their capacity for acquiring food from soil sources. Characteristics of the Cereal Group The cereals possess distinct characteristics of growth. The roots branch just below the surface, and each shoot produces feeding roots, which distribute themselves in every direction, and thus absorb food from the lower layers of the soil as the plant grows older. Because of their wide root system, and because L 178 FRRTILIZERS of the character of ther feeding rootlets, they are able readily to acquire food from the insoluble phos- phates and potash compounds of the soil, though they are unable to feed to any extent upon the insoluble nitrogen. Furthermore, inasmuch as the most rapid development of many of these crops takes place early in the summer, before the conditions are favorable for the rapid changing of organic nitrogen into nitrates, they are, with the exception of Indian corn (maize), specifically benefited by early applications of nitrogen in the form of nitrate. The corn, on the other hand, which makes its most rapid growth after the other cereals are harvested,—in July or August,— when the conditions are particularly favorable for the de- velopment of nitrates, do not usually require as large proportions of nitrogen as of the mineral constituents, particularly the phosphates. That is, wheat, rye, oats and barley are specifically benefited by the early appli- cation of quickly available nitrogen. Characteristics of Grasses and Clovers Forage crops, including both the grasses and clovers, constitute another group, in so far as their use is con- cerned, though possessing marked distinguishing char- acteristics. Of the grasses, nearly all species are perennial, though their length of life depends upon the method of eropping and upon the character of the soil. They send their fibrous roots into the sur- face soil in the same manner as the cereals, though they differ from them in forming a set of buds which CHARACTERISTICS OF GROWTH 179 become active in the late summer and develop new roots and shoots. , They resemble the cereals in their power of acquiring mineral food, and are even more benefited by the application of nitrogen, since the chief object in their use is to obtain the nitrogenous substances contained in leaf and stem in the form of pasture, forage or hay, rather than the matured grain. Hence, nitrogen, which promotes this form of growth, is an important constituent, and under any conditions there should be a liberal supply provided. The clovers, on the other hand, are not perennial, with the partial exception of “white” or “Dutch” elover, and with this exception they all possess a tap- root, which penetrates downward, and as it descends, throws out fibrous roots into the various layers of soil. They are capable of readily acquiring their mineral food, both because of their large root systems and because of the character of the roots. They, how- ever, differ in one very important particular from the cereals and grasses, in that under proper conditions, as already pointed out (p. 118), they are capable of acquiring their nitrogen from the air. Thus with liberal dressing of only phosphoric acid and potash, maximum crops may be secured. They are “nitrogen gatherers,” and the tendency of their growth is to im- prove the soil for the nitrogen consumers, or for those that obtain their nitrogen only from soil sources. Root Crops Another class of plants, differing from those already described, includes the root crops, as beets, mangels, 180 FERTILIZERS turnips and carrots. These plants cannot make ready use of the insoluble mineral constituents of the soil. Hence, in order to insure full crops, they must be liberally supplied with available food. Of the three classes of fertilizing constituents, the phosphates are especially useful for turnips, while the slower- growing beets and carrots require that the nitrogen shall be in quickly available forms. The proper fertilization of sugar beets, for example, is of great importance, since not only is the yield affected by fertilization, but the quality of the beet for the production of sugar. White potatoes and sweet potatoes, the one a tuber, the other an enlarged root, constitute another class which does not possess strong foraging powers. They require their food in soluble and available forms, and with suitable soils potash is the ingredient that is especially useful in the manures applied. Market-garden Crops Another group of crops is distinguished as a class, not so much because of their peculiar habits of growth as because of the objects of their growth, though this latter fact has a very important bearing upon economical methods of fertilization. This elass in- eludes what are called “market-garden crops,” as lettuce, beets, asparagus, celery, turnips, cucumbers, melons, sweet corn, beans, peas, radishes, and various others. The particular object in raising these is to secure rapidity in growth, and thus to insure high quality, which is measured by the element of succu- FRUIT CROPS A DISTINCT CLASS 181 lence. In order that this may be accomplished, they must be supplied with an abundance of available plant-food, and since nitrogen is the one element which more than any other encourages and stimulates leaf and stem growth, its use is especially beneficial to all of these crops. They must not lack for this element in any period of their growth, though, of course, a sufficiency of minerals must be supplied in order that the nitrogen may be properly utilized. Because of their high commercial value, the quantity of plant-food applied may be greatly in excess of that for any other of the groups, and profits, as a rule, are measured by this excess rather than by the proportion of the elements. Fruit Crops Another distinct class of crops, though differing materially in their individual characteristics, as well as in their time and period of growth, are the fruits. These differ from most other crops, in that a longer season of preparation is required, in which the growth may be so directed as to prepare the plant or tree for the proper development of a different kind of product, namely, fruit, as distinct from grain or seed in the cereals, or succulence in the vegetable crops. The fruit differs in its characteristics from the ordinary farm crops, in that its growth and development require a little different treatment, since it is necessary that there shall be a constant transfer of food from the tree to the fruit throughout the entire growing season. The growth of each succeeding year of tree and fruit 182 FERTILIZERS is dependent, not altogether upon the food acquired during the year, but as well upon that acquired in the previous year, and which has been stored up in bud and branches. A knowledge of the habits of growth, the period of growth and the object of the growth of this class is, therefore, useful as a guide to the eco- nomical supply of the essential elements of growth. These crops must be provided with food that will en- courage a slow and continuous rather than a quick growth and development. SYSTEMS OF FERTILIZING SUGGESTED A careful review of the foregoing facts furnishes abundant evidence of the impracticability of attempts to give information concerning the use of fertilizers that will apply equally well under all of the conditions of farming that may occur. Nevertheless, there have been a number of methods or systems of fertilization suggested, each of which possesses one or more points of advantage. A System Based Upon the Specific Influence of a Single Element The one which has perhaps received the most atten- tion, doubtless largely because one of the first pre- sented, and in a very attractive manner, is the system advocated by the celebrated French scientist, George Ville. This system, while not to be depended upon absolutely, suggests lines of practice which, under SYSTEMS OF FERTILIZING 183 proper restrictions, may be of very great service. In brief, this method assumes that plants may be, so far as their fertilization is concerned, divided into three distinct groups. One group is specifically benefited by nitrogenous fertilization, the second by phosphatie, and the third by potassic. That is, in each class or group, one element more than any other rules or dominates the growth of that group, and hence each particular element should be applied in excess to the elass of plants for which it is a dominant. In this system it is asserted that nitrogen is the dominant ingredient for wheat, rye, oats, barley, meadow grass, and beet crops. Phosphoric acid is the dominant fer- tilizer ingredient for turnips, Swedes, Indian corn (maize), sorghum and sugar cane; and potash is the dominant or ruling element for peas, béans, clover, vetches, flax and potatoes. It must not be understood that this system advocates only single elements, for the others are quite as important up to a certain point, ‘beyond which they do not exercise a controlling influence in the manures for the crops of the three classes. This special or dominating element is used in greater proportion than the others, and if soils are in a high state of cultivation, or have been manured with natural products, as stable manure, they may be used singly to force a maximum growth of the crop. Thus, a specific fertilization is arranged for the various: rotations, the crop receiving that which is the most useful. There is no doubt that there is a good scien- tific basis for this system, and that it will work well, particularly where there is a reasonable abundance 184 FERTILIZERS of all of the plant-food constituents, and where the mechanical and physical qualities of soil are good, though its best use is in “intensive” systems of prac- tice. It cannot be depended upon to give good results where the land is naturally poor, or run down, and where the physical character also needs improvement. A System Based Upon the Necessity of an Abundant Supply of the Minerals Another system which has been urged, notably by German scientists, is based upon the fact that the mineral constituents, phosphoric acid and_ potash, form fixed compounds in the soil, and are, therefore, not likely to be leached out, provided the land is con- tinuously cropped. They remain in the soil until used by growing plants, while the nitrogen, on the other hand, since it forms no fixed compounds and is perfectly soluble when in a form useful to plants, is lable to loss from leaching. Furthermore, the mineral elements are relatively cheap, while the nitro- gen is relatively expensive, and thus that the eco- nomical use of this expensive element, nitrogen, is dependent to a large degree upon the abundance of the mineral elements in the soil. It is, therefore, advocated that for all crops and for all soils that are in a good state of cultivation, a reasonable excess of phosphoric acid and potash shall be applied, sufficient to more than satisfy the maximum needs of any crop, and that the nitrogen be applied in active forms, as nitrate or ammonia, and in such quantities and at MINERAL SUPPLIES ADVANTAGEOUS 185 such times as will insure the minimum loss of the element and the maximum development of the plant. The supply of the mineral elements may be drawn from the cheaper materials, as ground bone, tankage, ground phosphates and iron phosphates, as their tendency is to improve in character; potash may come from the erude salts. Nitrogen should be applied chiefly as nitrate of soda, because in this form it is immediately useful, and thus may be applied in frac- tional amounts, and at such times as to best meet the needs of the plant at its different stages of growth, with a reasonable certainty of a maximum use by the plants. Thus no unknown conditions of availability are involved, and when the nitrogen is so applied, the danger of loss by leaching, which would exist if it were all applied at one time, is obviated. This method also possesses many advantages, par- ticularly where the “intensive” system is practiced, though it is also useful in quickly building up worn- out soils, or those naturally poor, because in any case these must be provided with liberal supplies of the minerals, and when these only are applied, the im- mediate outlay is far less than if the expensive ele- ment, nitrogen, were included; and a greater economy in the use of nitrogen is accomplished if it is added in small amounts when required. Besides, in the im- provement of soils, the liberal application of the minerals is conducive to an abundant growth of the legumes, which are able to acquire their nitrogen from the air, thus reducing to some extent the outlay for this expensive element. This system is strongly 186 FERTILIZERS recommended where cheap phosphatic and potassic materials are readily accessible, as is the case in those countries where it is successfully used. A System Based on the Needs of the Plants for the Different Elements as Shown by Chemical Analysis Another system of fertilization is based upon the theory that the different plants should be provided with the essential elements in the proportions in which they exist in the plants, as shown by chemical analysis. Different formulas are, therefore, recom- mended for each crop, the constituents of which are so proportioned as to meet its full needs. This method, if care is taken to supply an abundance of all the necessary constituents, may result in a com- plete though perhaps not an economical feeding of the plant, since it assumes that a plant which con- tains a larger amount of one constituent than of another requires more of that constituent in the fer- tilizer than of the others. It does not take into con- sideration the fact that the plant which contains a larger amount of one element than another may pos- sess a greater power of acquiring it than one which contains a smaller amount. Neither does this system take into consideration, as already pointed out (p. 178), that the period or time of growth of the plant also exercises a consider- able influence in indicating the capability of the plant to acquire its necessary food from the stores of the FERTILIZING POT-PLANTS 187 soil, as may be illustrated by wheat and Indian corn, which both contain a relatively high content of nitrogen. Under good conditions of soil, wheat is specifically benefited by heavy dressings of quickly available nitrogen. Corn is not, and one reason is, that they possess different powers of acquiring food, due, to a considerable extent, to the difference in their time of growth, as well as to the period or time of their most rapid growth. This method may, however, be applied with very great advantage in greenhouse work, or in growing market-garden crops, where the amounts in the soil are not regarded as of importance, and excessive amounts of all are added. The system has been elaborated to a great degree of nicety for the grow- ing of greenhouse crops, flowers, and foliage plants, so much so that now artificial manure cartridges are prepared, which contain the amounts and kinds of food shown by the analysis of the different plants to be needed for their growth and full development. “The manure has the form of a fine powder, enclosed within a metallic wrapper, and firmly compressed into the shape of a cartouche or capsule, cylindrical in form, about three-fourths inch across and one-half inch in depth. It is simply thrust into the soil of the pot to a depth of one-half or one inch, and allowed to remain. After a time it is found that the fertilizer gradually disappears, and at length nothing is left but the little pill-box-like wrapper, which originally contained the mixed fertilizing powder.” * *“The Gardener’s Chronicle,” London, England. 188 FERTILIZERS A System in Which the Fertilizer is Applied to the “Money Crop” in the Rotation Another system is also recommended, which is well adapted for “extensive” farming, where the ma- jority of crops which are grown in rotation possess a high fertility value and a low commercial value, and where one crop is regarded as the chief ‘“money- maker.” The system demands that to this crop shall be applied such an abundance of plant-food as to insure a continuous feeding, and a consequent max- imum production, even though adverse conditions intervene. Thus by a liberal supply of food, a money crop is secured which is as large as climate and sea- sonal conditions will permit, though which does not require all of the food applied. Hence the residue may be depended upon to fully nourish the remaining crops in the rotation, or at least the immediately suc- ceeding _ ones, thus saving direct outlay for them. This system may be illustrated as follows: On soils in good physical condition, and naturally well adapted for growing potatoes, this crop is se- lected as the “money-maker” in the rotation, which consists of corn, potatoes, wheat, clover and hay. The potato crop is fertilized so liberally, say with 1,500 pounds per acre of a fertilizer containing — Natrogen:"'s co Siege) te eee eee 4% Phosphoric: Acidy..¢ ssa cusp h (et aihet ia vor arte 6% Potash 22 is. \ sper ee cere ee ee 10% as to insure its maximum growth under average con- ditions. The removal of a large crop would still IRRATIONAL SYSTEM OF FERTILIZINGE 189 leave a large residue of plant-food, which would pro- vide the following wheat crop with at least all of the mineral elements necessary to produce a maximum erop. If the wheat does not show vigorous growth in the spring, it is lightly top-dressed with nitrate of soda, which not only feeds it directly with nitrogen, but strengthens and invigorates the plant, enabling it to secure the minerals needed. The removal of a large crop still leaves an unused residue, upon which the clover crop following is also able to make a maxi- mum growth, and thus three crops are fertilized with the one application. The hay is either fertilized with both the minerals and nitrogen, or lightly top-dressed with nitrogen early in the spring. The yard manure, accumulated from the residue of straw, hay and corn, is applied to the corn, which, being a gross feeder, is able to obtain from this an abundance. Thus, by the heavy application of fertilizer upon the “money crop,” all the crops in the rotation are benefited. This method possesses many valuable features, and is, perhaps, quite as well adapted as any other for this system of farm practice. An Irrational System The most expensive and irrational system of all, and one more commonly practiced than any other in general farming, may be termed the “hit or miss” system; if a “hit” is made, there is a profit, if a “miss,” the loss is trifling. In this system, no special thought is given to the character of the crop or its 190 FERTILIZERS needs. If the farmer can afford it, he purchases a fertilizer, without regard to its composition, and ap- plies it in very small amounts. If it happens to con- tain that element which is particularly needed for the plant to which it is applied, a profit is secured. In too many cases, however, the constituents added are already in abundance in the soil, or so little of the fertilizer is used as to preclude any profit. SUMMARY With the exception of this last system, there are good features in all of these suggested methods of use, and it rests with the farmer to select the best points from each, or rather to use the suggestions in each which are in his judgment more applicable to his econ- ditions. They are all based upon underlying principles, and pre-suppose a knowledge of them on the part of the farmer. They are, at best, but guides or sign-posts pointing toward better methods in the use of fertil- izers, rather than absolute rules to be blindly followed. The suggestions here and in subsequent chapters, in reference to the use of fertilizers, are formulated from the best information obtainable by the writer, and mainly from two sourees: First, the results of experimental inquiry, and, second, the results of the observation and experience of practical men. In no case can absolute rules be laid down. Farmers may safely rely on the well-established principles, but each must remember that the use of the principles must be modified according to his own conditions, CHAPTER X FERTILIZERS FOR CEREALS AND GRASSES Ir was already been pointed out (p. 175) that these crops are classed as possessing a relatively low commercial value and a relatively high fertility value, and that, from a practical standpoint, in any fertiliza- tion of them a possible profitable return should be borne in mind. This is, of course, necessary in all cases, but is particulary necessary where an increased yield, as great as can be expected from an application of proper fertilizing materials, cannot possibly result in an extraordinary profit, a result quite possible with certain crops of the opposite class. The possible in- crease in yield, too is, dependent on the conditions of soil and season, and if these latter are such as to forbid a maximum increased yield, the immediate profits from the application are considerably reduced. It has been shown, too, by careful experiments, that, on the average, at least one-third of the nitro- gen applied to these crops, though contained in the best forms, is not secured in the crop, even under the most favorable conditions; that is, in any case certain amounts are lost through drainage, the growth of weeds and denitrification; and, further, that the minerals must exist in the soil, or must be supplied in sufficient excess, otherwise, the utilization of the (191) 192 FERTILIZERS nitrogen by the plant is still further reduced. The expense of fertilizer per unit of increase in these crops is, therefore, relatively greater, even under the best conditions of its use. A bushel of wheat, with its accompanying straw, will contain, for example: NItTORON o/ Gee vcya nar pug aE his a 1% lbs. Phosphoric, seid. s0.4):) cus eae tates: fae a Poteshssfots. Ne on enen kaa has! pn, Oe 1G It will be observed that the amounts of fertilizer ingredients contained in the crop are such that, if the seasonal conditions are perfect, so that the maximum of the amounts applied are recovered in the crop, the cost of fertilizers per bushel of increase is still rela- tively high, thus showing that great care must be exercised in order that a direct and immediate profit may be secured. Nevertheless, since the cost of pre- paring the land and of harvesting the crop is but slightly greater for a large crop than for a small one, the larger returns for the labor very frequently pay well for the application of the material, even though the margin of money profit is small. In crops of this sort therefore, and especially when grown on the “extensive” plan, an important point to be de- termined is whether the land is deficient in all of the constituents for grain and hay growing, or whether only one or two are lacking, in order that in the ap- plications made, only those constituents are supplied that are necessary, and adding to an excess already present is thus avoided, with a consequent saving in the cost of the fertilizer. FARMERS SHOULD EXPERIMENT 193 EXPERIMENTS TO DETERMINE THE LACKING ELEMENT The lacking element cannot be fully determined, except by direct experiments by the farmer himself. That is, no general principle can be depended on as an absolute guide. He should learn whether his soil is deficient in any of the elements, and, if so, which ones should be applied to the different crops in his rotation. A careful study along this line, too, will show whether it is fertilization that is required to meet seeming deficiencies, for it frequently hap- pens that the needs of the soil are not so much for added plant-food as for better management of the soil in other respects, in order that natural supplies may be made more available. It may seem, at first glance, that experimenting should be left to the experiment stations, and that farmers should be advised by them in respect to the needs of their soils in respect to plant-food. This is partly true, but the proper function of experiment stations is to establish principles, the application of which must be left, in large part at least, to the intelligence of those who are to utilize them. The farmer must study his own conditions. Scientific in- quiry has established the facts that soils differ in their content of the different plant-food elements, and that those of practically the same chemical composition differ in respect to their physical qualities, both of which conditions exercise an important influence upon the availability of the constituents, M 194 FERTILIZERS This experinfenting may also seem to be a trouble- some operation, yet, if thoughtfully managed, it will mean but little extra labor, and the resulting gain may be far in excess of the cost of the work. For example, if it is shown that fertilization under certain conditions is not the thing needed, and, therefore, not profitable, it saves possible outlay at once; if it shows that the application of certain of the constituents is a profitable practice, it enables the adoption of a systematic scheme of fertilization. A Scheme for Plot Experiments The following simple scheme of plot experimenting has been suggested, and it admits of determining many of the points involved. This scheme includes ten plots, in which three are to be cropped without manure, as cheek plots, in order to show the produc- tive capacity of the unmanured land. The plots may vary in size, though it is desirable that they should ‘contain at least one-twentieth of an acre, and that they should be long and narrow, in order to include as many inequalities of the soil as possible, though in any case land as uniform as possible in physical and chemical qualities, and fairly representative, should be selected. The following plan permits of a study of the effect of the application of individual constituents, and of their various combinations. If desired, in order to simplify the work in the begin- ning, only the first four plots need be taken. This will reduce the labor, and, at the same time, permit PLAN OF EXPERIMENTS 195 a study of the soil’s deficiencies in respect to single elements of plant-food, and the relative needs of the different crops for the various constituents. PLAN OF EXPERIMENTS— SIZE OF PLoTs, #5 OF AN ACRE Plotuls Check. No fertilizer. iriktch a Nitrateroly S008: 2: cute 6 heures et cues, SL DSs e ITS. \“Superphosphate..../ 26)! .. Sete (ime te GLVis CoiMarate.of potashos, a. /f haiti lay robe Bee eas Check. No fertilizer. ‘‘ VI. Nitrate of soda, 20 lbs. Superphosphate. 16 “‘ Vil> Nitrate of soda, 20 “‘ Potash... = . Sr —) MULE sPhoshoric: acid, 40. °° Potash. 3...) 2-8." ‘‘ IX. Nitrate of soda, 8 ‘‘ Superphosphate, 16 ‘‘ Rotash@er.. cate: ES eg tte i 8 ne. Check. No fertilizer. The rate of application per acre is greater than would naturally obtain in practice, in order both to facilitate the distribution of the fertilizer, to furnish a sufficient abundance of the constituent, and to pro- vide against unfavorable conditions. Preferably, the application should be made broad- east, and before planting, if an uneultivable crop, though for cultivable crops it may be applied later and harrowed in. It will be observed that the amounts of fertilizer are one pound per square rod, or multiple thereof. Thus, in order to insure an equal distribution over the entire area, it may be roughly divided into plots of a square rod, and the required material for each rod applied separately. Careful weights should be made of the yields of the different plots, as a basis 196 FERTILIZERS of comparison. The same fertilizers should be used on the different crops of the rotations, and, as inter- est is increased in the work, different forms and amounts of the various constituents may be intro- duced. Results That May Be Attained If it is found that for a certain crop only one of the applied constituents profitably increases the yield, then that should be used until the need of the others is apparent. If two are needed to accomplish the results, use two, and so on; though in the long run, or as the practice approaches the “intensive” system, all will doubtless be required. In “extensive” farming this is a very desirable line of experimentation, and can be carried out by individual farmers. It is useful not only in showing the deficiencies of the soil for the various crops, but is educative in its character, as it familiarizes the farmer with the materials that are used in making fertilizers, and encourages exact methods of work. Since, as already stated, the need very frequently is not so much for added fertility as it is for better preparation and cultivation of the soil, or for amendments such as lime, it would be a desir- able practice to inelude in the number of plots here indicated one or two in which the cultivation of the soil was made more perfect, in order to determine whether the need is for more fertility elements or whether it is for better tillage, the effect of which is to render more of the soil constituents available to THE RESULTS OF EXPERIMENTS 197 the plant. One or two to which lime is added may be advisable, in order to determine whether this sub- stance is needed either to correct acidity or to make available otherwise unusable compounds. This method, while particularly desirable where “extensive” methods of practice prevail, is of less importance where the aim is to grow maximum erops, in which ease both the crop and its rotation are to be considered, and the needs of the plant rather than the deficiencies of the soil require first attention. The results of experiments which have been con- ducted with great care in a number of states show that where “extensive” methods are practiced certain elements need not be added in the fertilizers; that is, that the soil contains such an abundance of them that the plant is able to obtain a full supply, at least, for a long time. For example, it has been shown that on the chief sugar-producing soils of Louisiana and Mississippi, and the cotton soils of Georgia and Texas, the addition of potash has been of less im- portance in the past than the other elements, and it frequently does not need to be included in the fer- tilizer, while phosphoric acid is always needed. The results of field experiments on this plan in New Jersey, on reasonably good, loamy soils, indi- eate that phosphoric acid and potash are of much more importance in fertilizers for corn than _ nitro- gen, whereas upon sandy soils, nitrogen and potash are of relatively more importance than phosphorie acid; that is, even where “extensive” practice is used there are conditions where one or more of the ele- 198 FERTILIZERS ments are not required in order to secure maximum erops, Which eliminates the necessity for an imme- diate outlay for those constituents that are not lacking. Where experiments of this sort have not been carried out and the specific needs determined, it becomes necessary to assume that all of the constituents are required, and to apply the amounts and _ propor- tions of those which the general considerations of the soil, season, climate and crop would seem to demand. As already pointed out, the methods of fertilization here suggested, though in many instances apparently positive, are not to be interpreted as absolute rules, but rather used as guides, based upon the best information that it has been possible to obtain, both as a result of scientific inquiry and of practical experience. THE IMPORTANCE OF SYSTEM IN THE USE OF FERTILIZERS The following rotation is assumed, in order to show the necessity of a definite system of work, which is quite as important in this branch of farming as in many others in which system is apparently ‘more essential,—though in fact it is quite as necessary to observe a definite system in the feeding of plants as in the feeding of animals with the plants: ILLUSTRATION OF A ROTATION Wirstiyyear. 04 's- sc 4). | 5) Maize (corn). Second year....... . - Oats. THITd VORP w. 2) psyiesops.« age NM RORG. Fourth year...... .. . Clover and timothy Pitth “years ts: :0\(.)".: (inten oy LeU, SYSTEMATIC FERTILIZATION 199 Indian Corn Exhaustive of the Fertility Elements Since in rotations of this sort a fair number of live stock is usually kept, a considerable amount of ma- nure is made, which should be carefully cared for and used, as it contributes materially to the success of the plan. The manure may be used in part on land for corn, and should be spread broadeast, practically as fast as made during the fall, winter and early spring. This plant, because it is a gross feeder, and also because it makes most of its growth during the sum- mer season, when activities in the soil are most rapid, is able to appropriate from the coarse manures a larger proportion of the constituents than would be possible for crops which make their greatest growth earlier or later in the season. In the summer, too, the condi- tions are most favorable for nitrification, and soils which possess a fair content of vegetable matter are usually able to furnish the nitrogen needed in addition to that supplied in the organic manures, particularly in the middle and southern states. The considerable amounts of potash required for the growth of stalks, and the phosphorie acid for the formation of grain, demand that a liberal supply of these constituents be provided, and the fertilizer for the corn should, there- fore, contain an abundance of available phosphoric acid and of potash. A crop of 50 bushels of shelled corn per acre, with the accompanying stalks, will remove, on the average, 80 pounds of nitrogen, 29 pounds of phosphoric acid, and 55 of potash. It is an exhaustive crop. A fer- 200 FERTILIZERS tilizer, therefore, that would furnish 30 pounds of phosphoric acid and 40 of potash would be regarded as a fair dressing for land of medium quality. A part of the phosphoric acid, at least, should be in a soluble form, in order to supply the early needs of the crop. The remainder may consist of ground bone or tankage, if the phosphoric acid in these can be obtained more cheaply, since they will decay rapidly enough to supply the demands for the later growth. The potash may be either muriate of potash or kainit, though the former is preferable if it is applied in the drill, which is, if used in these amounts, a perfectly safe practice so far as injury to the plant is concerned; though fertilizers containing large amounts of potash salts are preferably applied broadcast on raw ground of a clayey nature, and well worked into the soil, thus insuring a good distribution. The cost of an application of this sort will be relatively small, and the minerals added will be more than sufficient to provide for a considerable increase in crop. If the land is light and sandy, nitrogen should be added, even though it has received a good dressing of yard manure, as these lands are usually deficient in this element, and organic forms are usually quite as useful as the soluble nitrate or ammonia, since the seasonal conditions during the period of growth are favorable for the rapid change of the nitrogen in materials of good quality, like blood, concentrated tankage, or cotton-seed meal, into nitrates. The amounts of nitrogen needed would, under ordinary conditions, be supplied by 100 pounds of high-grade blood, or 200 pounds of cotton-seed meal. The nitro- FERTILIZERS FOR CEREALS 901 gen may also be obtained by substituting tankage for the superphosphate, though it is not so desirable a practice. In this matter of fertilizing, it must be remembered that weeds appropriate plant-food quite as readily as the corn, wherefore in order to obtain the best results from the fertilizers added, clean cultivation should be practiced. Oats For the oat crop that follows corn, and which makes its best growth early in the season, before nitrification is rapid, quickly available forms of nitrogen are very desirable; and inasmuch as the oats require an abun- danee of phosphates, a fertilization with phosphoric acid is also essential. Hence, fertilizers consisting of mixtures of nitrate of soda and superphosphates have proved of great value for this crop. If mixed at home, they should be applied immediately after prepa- ration, for a loss of nitrogen may result if the mix- ture is allowed to stand for any length of time. An application of 8 pounds of nitrogen and 18 of phos- phorie acid, or 200 pounds per acre of a mixture of 50 pounds of nitrate of soda and 150 of acid phosphate, has proved quite as profitable on medium soils as heavier applications, mainly because the oat crop is a less certain one than corn; besides, it frequently suffers severe losses in harvesting, which increase the risk from an expensive fertilization. The application of potash is not so necessary if added in the fertil- izer for corn, as suggested, except on light, sandy soils. 202 FERTILIZERS Wheat For the wheat crop following oats, the rest of the farm manure on hand may be applied after plowing, well harrowed into the surface soil, and a fertilizer ap- plied which shall be rich in available phosphoric acid, and which shall contain only a sufficient amount of nitrogen in quickly available forms to insure a good fall growth. When the land has been well fertilized for previous crops, a dissolved animal bone super- phosphate is an excellent fertilizer for wheat, because containing the elements, phosphoric acid and nitrogen, in good forms and proportions. If more nitrogen is needed than is provided by 200 to 300 pounds of this fertilizer in order to mature the crop, which is fre- quently the case, particularly if the winter has been severe, or if the land is light, it may be applied in the spring, and preferably in the form of a nitrate, which distributes readily, and is immediately available, ad- vantages not possessed by other forms. At this period of its growth, the crops need to make a rapid appro- priation of nitrogenous food, though the conditions are not yet favorable for the change of nitrogenous organic compounds in the soil into the available nitrate. The top-dressings should be made as soon as the crop has been well started, and should range from 75 to 150 pounds per acre, according to the character of the soil and previous fertilization. The better the natural character of the soil and its treatment, the larger the dressing that may be applied with possible profit, though in no ease should it exceed the larger amount. FERTILIZERS FOR CLOVER AND TIMOTHY 203 Clover For the clover which follows the wheat, only the minerals, phosphoric acid and potash, need be applied. An inereased return is likely to follow such an application, as the clover is not able to utilize to the fullest extent the nitrogen from the air except when the soil is supplied with an abundance of mineral food. An application which will furnish 12 pounds of phos- phorie acid and 25 pounds of potash per acre marks the minimum dressing, and it may be applied with advantage immediately after the wheat is harvested. Timothy The timothy, the next crop in the rotation, is a member of the grass family, and is especially benefited by nitrogenous fertilization, and top-dressings in the spring with nitrate of soda have proved of great value on soils well supplied with minerals, though experienced farmers have learned that better results are obtained if the minerals are applied with the nitrate, thus in- suring a better growth and development of plant. A mixture made up of 150 pounds of nitrate of soda, 100 of acid phosphate and 50 of muriate of potash, at the rate of 300 pounds per acre, is now used by many successful hay growers. The application should be made as soon as the crop has well started in the spring. The system of fertilization here outlined is not to be advocated except under circumstances where it is not 904 FERTILIZERS possible or practicable to supply such an abundance of plant-food as will guarantee a maximum production, as in “intensive” practice, in which the yield is measured by climatie and seasonal rather than soil conditions, but rather such additions as will return a profit and at the same time tend toward the improvement of. soil. This system is economical in the use of nitrogen, the most expensive element. It provides a_ sufficient amount of available plant-food to insure a reasonable increase in erop, and it is well adapted to lead the farmer by easy steps from the “extensive” to the. “intensive” system of farming. A Gain of Fertility by the Rotation System Assuming that the increased yield of corn is 20 bushels, with accompanying stalks, of wheat 10 bushels per acre, of oats 15 bushels, of clover % ton, and of timothy % ton, the amounts applied will be practically sufficient to furnish all of the potash contained in this increase, and more than sufficient to meet the demands for phosphoric acid. That is, by this system, there has been applied in the materials 380 pounds of nitrogen, 64 of phosphorie acid and 80 of potash. While, if this increased crop was secured, the following amounts would be required: 71 pounds of nit»ogen, 31 of phosphoric acid and 79 of potash. The considerable amounts of plant-food contained in the yard manure, and the gain from the roots and stubble of the clover, serve to supply the balance of nitrogen required, and to provide a store of unused residue for future erops. NECESSITY OF AN EXCESS OF FOOD 205 The method, if adopted, would be more rational, and likely to result in more satisfactory returns than the one now generally practiced, namely, to purchase with- out particular regard to the character of the materials furnishing the constituents, or their proportions, and to apply, on the average, even less per acre than is here recommended. Assuming that 200 pounds per acre of the average corn fertilizer, showing a composi- tion of 2.5 per cent nitrogen, 8 of phosphoric acid and 5 of potash, were applied only to the crops corn, oats and wheat, omitting both clover and timothy, there would have been added 15 pounds of nitrogen, 48 of phosphoric acid and 30 of potash, amounts of each too small to provide for a large increase in crop, provided all were needed. The Necessity of Adding More Plant-food than is Required by a Definite Increase in Crop It may be asked, why add more of the constituents than is necessary to provide for a definite increase in crop? Assuming that the average yield of the land is twenty bushels of wheat per acre, and the aim is to secure thirty bushels, why not add the constituents in the amounts and proportions necessary to provide for this extra increased yield, rather than any excess of these amounts? The answer is, that in order that such a result may be accomplished, the conditions would need to be absolutely perfect, so that the plant would have at its command the amount of food needed each day. If a period in the growth 206 FERTILIZERS of the plant should be so wet or so dry as to prevent the plants from acquiring the food necessary for their continuous growth, there would be no opportunity for them to gather food faster, when the better conditions followed the unfavorable conditions, and thus to over- come the ill effects of the period of partial starvation. In other words, if there were only sufficient food to supply the plant under normal conditions of season, the plant, after a period of time during which there was no growth, could not grow faster than it did before, hence it could not catch up in its growth and make a full crop. Furthermore, the plan of applying only that needed for the increase must necessarily assume that the plant-food is in the best forms, and that the physical conditions of soil are so perfect as to cause it to absorb and retain all the food applied, and in such a manner as to permit it to be readily obtained by the plant. A further advantage is to enable the clover plant in the rotation to fully exercise its power of acquiring nitrogen from the air. Moreover, if properly carried out, it fulfils the idea of successful agriculture ; viz., the production of profitable crops, while at the same time not reducing, but increasing, the potential fertility of the soil. The System Should Be Modified 1f no Farm Manures are Used In this rotation, if no manures are available, as indicated, then the amounts and kinds of fertilizers should be somewhat changed. For example, if it was EXCLUSIVE USE OF FERTILIZERS 207 necessary to supply the corn crop with a sufficient abundance of all the elements in artificial forms, then the proportions of nitrogen should be somewhat greater and the total amounts of the constituents applied to the different crops considerably increased. For corn, a mixture consisting of 20 pounds of nitrogen, 30 of phosphoric acid and 50 of potash should be applied, and if grown upon raw ground rather than upon sod, it would be desirable to still further increase the nitrogen. The oats could be fertilized, as before ree- ommended, while the wheat should have an increased supply of both nitrogen and phosphoric acid,—double the amounts recommended when used with manure,— besides an addition of at least 10 pounds per acre of potash. The fertilizing of the clover and timothy need not be changed. If, in a rotation of this character, barley were substituted for oats and rye for wheat, the fertilization need not be materially changed, though the rye possesses a slightly greater power of acquiring phosphorie acid than wheat, and the nitrogenous top- dressings may be omitted, unless the crop is grown primarily for straw rather than for grain. The barley is also less able to acquire its phosphoric acid than the oats, and is especially benefited by nitrogen, though eare should be exercised to regulate the amounts ap- plied in order to prevent lodging, which affects both the yield and quality of the grain. If in the rota- tion the timothy hay is omitted, then the fertilization for the corn may be reduced, as on good soils the yard manure, together with the plant-food stored in the surface in the clover sod, will furnish an abundance. 208 FERTILIZERS FERTILIZERS FOR A SINGLE CROP GROWN CONTINUOUSLY When it is desirable to grow any one or all of these crops continuously (and this practice may be followed with advantage, particularly when a legumi- nous catch-ecrop is seeded with the main crop, which insures a continuous occupation of the land and also provides vegetable matter and nitrogen), the fertiliza- tion would naturally be somewhat different, and, as a rule, would require more nearly even quantities of the different constituents. For corn, a fertilizer supplying 20 pounds of nitrogen, 40 each of phosphoric acid and potash, would provide for a liberal increase in the yield from year to year. The nitrogen should prefera- bly be in good organic forms, which would decay rap- idly enough to supply the needed available nitrogen during the growing season. The phosphoric acid may be drawn partly from superphosphates and partly from organic compounds, as ground bone and tankage, pro- vided these latter may be secured at as low a price as the superphosphate, and the potash appled in the form of a muriate or kainit. Fertilizers may be applied broadeast and well harrowed into the soil, or part may be distributed in the row at time of planting. If a catch crop were seeded to be used as green manure, as, for example, crimson clover, the applica- tion of nitrogen may be very materially reduced. This practice has been followed with advantage in the middle and southern states. For continuous wheat growing, a fertilizer may be FERTILIZERS FOR A CONTINUOUS CROP 2()9 used at time of seeding which supplies 10 pounds of nitrogen, 40 of phosphoric acid and 20 of potash. A small part of this nitrogen would better be in the form of a nitrate, which will encourage a good top-growth in the fall, as well as a deep root system; the phos- phoric acid should be soluble, in order to supply the immediate needs of the young plant, and the potash in the form of a muriate. Such an application would provide for a very considerable increase in crop, par- ticularly if followed in the spring by a top-dressing of 100 pounds per acre of nitrate of soda. The top-dressing with nitrate of soda is, however, not always advisable. The chief objection to its use is that it does not encourage, but frequently seems to retard, the growth of clover, though its very great advantage is that it encourages the deeper rooting of the wheat and the more rapid growth of grasses. If continuous cropping of wheat is practiced, clover should be seeded with it, in order that the ground _ may be constantly occupied, and thus prevent leaching, as well as mechanical losses of fertility, and also to supply vegetable matter containing nitrogen for the succeeding crop. When a system thus outlined has been continued for a few years, the nitrogen in the fertilizer may be largely omitted. The same considerations apply to rye as were in- dicated for wheat. Oats are seldom grown as a continuous crop, though if it should be desirable, a fertilizer furnishing at least 20 pounds of nitrogen, 25 of phosphoric acid and 10 of potash would be a good dressing, care being taken that a large portion N 910 FERTILIZERS of the nitrogen exists as nitrate or as ammonia, in order to stimulate and strengthen the early growth of the plant. For the grass crop, or continuous mowing land, a fertilizer rich in nitrogen and potash should be applied. A good application in the spring may consist of 25 pounds of nitrogen, 15 of phosphoric acid and 25 of potash, and immediately after the hay is har- vested a further application of at least 20 pounds of nitrogen and 380 each of phosphoric acid and potash should be applied. The nitrogen in this ease may consist partly of organic forms, though the soluble nitrogen is to be preferred as top-dressings where it ean be procured at such a price as to make it compara- ble with other forms. The nitrogen of bone, tankage and other slower-acting forms is excellent for the grasses, though these should be preferably applied and well worked into the soil previous to seeding. The early spring application should consist largely of solu- ble nitrogen, both to encourage a rapid appropriation of this element by the plant early in the season, as well as a deeper root-system, and consequently a greater drought-resisting power, and also to provide the elements necessary for the inereased crop. The sum- mer or later application stimulates and strengthens the roots for the coming season. If an aftermath crop is removed, or if it is pastured, a further application may be made, which may consist largely of the mineral elements. This fertilization of the hay crop will also result in a richer product, for an abundant supply of nitrogen encourages a larger proportion of leaf growth, and consequently a smaller proportion of stem, contain- FERTILIZERS FOR MEADOWS 211 ing the less valuable woody matter. Lands that are well fertilized in this way, if properly seeded in the first place, may make profitable mowing crops for a long series of years, and good crops cannot be expected unless liberal fertilization is practiced. Fertilizers for Meadows For meadows used as pastures, a more liberal application of the mineral elements is recommended, since an abundance of these encourage the growth of the clovers, which make a richer herbage than the grasses. Heavy nitrogenous fertilization is expensive, and encourages the growth of the grasses rather than the clovers. Pasturing, while less exhaustive than hay cropping, nevertheless results in the gradual depletion of fertility, and an abundant growth of rich pasturage can only be secured where there is an abundant supply of available plant-food. Mixtures made up of acid phosphate, ground bone and muriate of potash in equal proportions, make very good dressings, if applied in sufficient quantity, three hun- dred to five hundred pounds per acre annually. The ground bone is recommended because it decays slowly, and thus furnishes a continuous supply of nitrogen and of phosphoric acid. The application should preferably be made both in spring and in late summer, in order to secure a good growth, as well as to encourage the introduction of the clovers. In any system of continuous cropping, or in fact in any sys- tem of rotation-cropping, in which an abundance of 212 FERTILIZERS organic matter is introduced in the way of green crops, or in decaying vegetable matter contained in roots, the land should occasionally receive a dressing of lime, both to supply that which the plants need, as well as to correct possible acidity of soil. WILL THIS SYSTEM of FERTILIZING PAY? That fertilization will pay if carried out, as is pointed out here, and upon lands not now producing paying crops, depends, of course, very largely upon the price of the crops, the cost of the materials, and the method of farming practiced. At the prices which have prevailed in the recent past, for both crops and fertilizing materials, there is no doubt that this reasonable fertilization, together with a good system of practice in other respects,—that, is, good plowing good harrowing, good drainage and good cultivation, —will result in very satisfactory returns. In fact, it has been shown by repeated experiments (see bulletins and reports of New Jersey Experiment Station) that the yields on land which is capable of producing an average crop of 15 bushels of wheat per acre, 30 of eorn and 30 of oats, may be more than doubled by an abundant supply of fertilizing materials. Such an increase results in an actual direct gain, as well as in the saving of labor per unit of product, which is accomplished when the larger crop is secured. The main point in this whole matter of fertiliza- tion is to understand that a fertilizer is a fertilizer because of the kind and form of plant-food contained WILL FERTILIZING PAY? PAIS in it; and that its best action, other things being equal, is accomplished when the soil possesses good physical qualities, when the management is also good, and when systematic methods are planned and adopted. “Hit or miss” fertilization, even for these crops, may pay, and doubtless, on the average does pay as well as some other things that farmers do, but does not pay as well as it might if better methods were used. CHAPTER XI POTATOES, SWEET POTATOES, TOMATOES AND SUGAR BEETS These crops differ from the cereals and grasses in that they are products of high commercial value, and are less exhaustive of plant-food constituents per unit of money value. As field crops they are usually grown in a rotation, and constitute one at least of the chief money crops. In sections near large markets these crops are, with the exception of sugar beets, divided into two classes, early and late, the early crop being regarded as the most profitable; hence greater efforts are made, both in the way of fertilization and of management, to secure a large and early crop, than is the case with the late crop. For the early crop the natural supply of plant-food in the soil is not a prime consideration. In districts distant from markets, the late crop is the only one grown to any extent, and because it has the whole season for its growth, greater dependence is placed upon the natural resources of the soil. While, as already stated, these crops are not regarded as exhaustive of plant-food elements in the same sense as the cereal crops are, because it fre- quently happens that a bushel of potatoes, or of sweet potatoes, or of tomatoes, will bring as much as a bushel of corn, or sometimes as a bushel of wheat, _ (214) FERTILIZERS FOR POTATOES 215 yet the amount removed in the entire crop may be quite as great as in the grain crop, because of the much larger number of bushels grown per acre. FERTILIZERS FOR POTATOES, EARLY CROP It has been demonstrated, both by experiment and practical experience, that good crops of early potatoes require an abundance of plant-food, and that on soils of good character a heavy fertilization is usually more profitable than a medium or light application. The plant-food removed by a fair crop— 200 bushels per acre of tubers—will, on the average, consist of 27 pounds of nitrogen, 12 pounds of phosphoric acid and 60 of potash. Even though the increase from the application of fertilizers is less than 100 bushels per acre, it is always advisable to add plant-food in considerable excess of these amounts: first, because the crop must be grown quickly; and second, because a large part of its growth must be made in the early season, before the natural conditions are favorable for soil activities. A study of the fertility composition of the potato shows that of the three essential constituents, the potash is contained in the greatest amount and the nitrogen next, while the amount of phosphoric acid contained in it is comparatively small. Most fertilizer formulas for potatoes are, therefore, pre- pared with the idea of furnishing a greater amount of potash than of nitrogen or phosphoric acid. A study recently made by the Geneva Experiment 216 FERTILIZERS Station* shows that the formulas prepared to con- tain the plant-food in nearly the proportions used by the entire potato plant, excepting that the phos- phorie acid is in considerable excess, were less useful than those containing very different proportions of the constituents, and which were based upon the experience of observing growers. That is, a formula of the first class, furnishing — INGGRO ROM is sss ee cae a ee Cs a 614 % Available phosphoric acid. ........ 5 % Potash ay sie iat beineliped s/n culeetette Peon od caine 10 % gave less satisfactory returns for the same amount applied than one furnishing — NICO OT Phere PE od leone N a ay Uwe arm nies 4% Available phosphoric acid. ........ 8% POLAT ey ce brane iets cede nae aN ak mae 10 % This latter formula is very generally used in sections where early potatoes are an important crop. The Time and Method of Application These are matters of considerable importance. It has been urged, particularly by German experi- menters, that the potash salts, when used in such excess as seems desirable, should be appled more largely to the crop preceding, rather than directly to the potato crop. This method has not been adopted in this country to any extent, and it is believed that * Bulletin No. 137, N. Y. State Exp. Sta. THE AMOUNT OF FERTILIZER DA our climatic conditions are such as to cause a very general distribution of the salts throughout the soil, if applied, in part at least, just before planting and thoroughly distributed by cultivation. At any rate, very satisfactory returns are secured from the direct application to the crop of fertilizers of this composi- tion. In reference to the method of application, while very good results are secured from the application of the fertilizers directly in the row, this is to some extent influenced by the character of the soil. Where the soil is somewhat heavy, and the circulation of water is not perfectly free, it is less desirable than where the soils are open and porous, and free cireu- lation is not impeded; though where the amounts applied are considerable, it is recommended that at least one-half of the fertilizer should be applied broadcast and worked into the soil, and the remainder placed in the row at the time of planting. Naturally, when the soils are poor, a concentration of the con- stituents is more desirable than when the surround- ing soil possesses reasonably abundant supplies of available food. The Amount to be Applied As already stated, the amount of the different con- stituents to be applied should be in considerable excess of that required by the actual increase in crop, both for the reasons already given, and because it is desirable in erops of this sort to insure a continuous and abundant feeding of the plant. Where “intensive” 218 FERTILIZERS practice is general, the amounts applied very frequently reach a ton per acre of the high-grade fertilizer already mentioned, though the necessity for so large an application as this has been questioned, particularly if it is expected to give rise to a profitable return in the crop to which the application is made, and though it can be readily seen that if conditions should not be favorable the larger amounts would be preferable. The result of investigations of this point by the Geneva Experiment Station* showed that an addition of fer- tilizers above 1,000 pounds per acre, or 40 pounds of nitrogen, 80 of phosphorie acid and 100 of potash, was not as profitable as 1,000 pounds. It must be remembered, however, that these experiments were conducted upon light soils, and on these entire de- pendence must be placed upon added plant-food. In the best potato sections of New Jersey, the application of a fertilizer of this composition ranges from 1,000 to 2,000 pounds per acre, while the majority of the growers use the smaller rather than the greater quantity. Many use the larger, and are of the opinion that it is a profitable practice, because of the greater certainty of securing a good potato crop, and because the unused residue provides for large yields of the subsequent crop without further applications. The growers of potatoes in the vicinity of Norfolk, as well as farther south, also find it profitable to be generous in the use of fertilizer for this as well as for other crops of high commercial value, *Bulletins 93, 112, 187, N. Y. State Exp. Sta. FERYVILIZERS SHOULD BE AVAILABLE I19 Form of the Constituents In the growing of potatoes, sulfate of potash is generally recommended in preference to the muriate, owing to the supposedly deleterious effect on the quality of the tubers resulting from the large quantities of chlorids contained in the muriate, though the dif- ferent forms, when properly applied, do not seem to materially influence the yield. That is, if muriate or kainit is applied previous to the planting of potatoes, the deleterious chlorids may be washed from the soil. There is no doubt that the sulfate improves the ap- pearance of the potatoes, making them more clean and uniform in size, though experiments that have been conducted do not show a material difference in the chemical composition of the tubers grown with any of the forms. The tendency on the part of the mu- riate seems to be to diminish the amount of dry matter, and inasmuch as the dry matter is mostly starch, the latter is thereby slightly reduced, though it has not yet been demonstrated that the good quality of the potatoes is measured by the content of starch.* In reference to the form of nitrogen, both theoret- ical considerations and the experience of growers con- firm the belief that for the early crop, a portion of the nitrogen should exist in the form of nitrate or ammonia and the remainder in quickly available organic forms, although no definite experiments have been conducted to determine this point, nor the one * Bulletin No. 137, N. Y. State (Geneva) Exp. Sta. Bulletin No. 80, N. J. Exp. Sta. 220 FERTILIZERS as to whether all of the nitrogen in the form of nitrate should be applied at the time of planting. A top-dressing after the potatoes have come up is a very desirable method of practice on light soils which have been liberally supplied with the minerals. On good potato soils, therefore, a good fertiliza- tion would consist of 800 pounds per acre, as a mini- mum, of a mixture containing: INGOs Omiya Oye ic Lie ieaten eu neem tT alpeatLS 1 3to 4% Phosphoric’ acidss '2y.gyaneo yee ts. 6 to 8 % Potash cy his © nea i cuicke cen RCA RCT 8 to 10 % The nitrogen is to be in quickly available forms; the phosphorie acid, also, is to be available, and the potash to be derived from sulfate, particularly if fine quality of crop, as indicated by appearance, is desired. If only yield is considered, the muriate is quite as serviceable. LATE POTATOES For late potatoes, the considerations in reference to the form of the constituents and the amount of the application, as suggested for early potatoes, do not always hold good, since in many cases the erop is able to secure a larger proportion of its plant-food from soil sources,—due, first, to the longer period of growth of the plant, and second, to the fact that the crop is usually grown upon soils naturally richer in the plant-food elements, though the proportion of pot- ash, as in the formulas already indicated, should be relatively large. The nitrogen may be reduced, and FERTILIZERS FOR SWEET POTATOES pA | the form of nitrogen may be derived largely from organic sources. Good formulas for late potatoes may consist of — Uplin fa} 2) 71s PO aS Re IP Ri Vevey tea 24 % Phosphoriciacidis 2) swear ies weenie 6% IPotashiysyrs esr iy).2! 65 is et a ecu al PGI ae 8% and the application may be from 600 to 800 pounds per acre. Where potatoes are grown in rotations with the cereal crops mentioned in Chapter X, the unused residue from the rather heavy application of fertil- izers to the potato crop is depended upon to very materially aid the growth of these, thus reducing the outlay for fertilizer for crops of a low commercial value. This practice is advantageous, though the prime object should be to feed the crop rather than the soil—that is, apply the fertilizer with the idea of securing a profit from it in the potato crop, rather than a possible profit in subsequent crops. SWEET POTATOES In the growing of sweet potatoes, the quality of the product is more important than in the ease of the white potato. The northern markets distinctly recog- nize quality in this crop, and it is measured by size, shape, and results in cooking. The potato that brings the best price in the different markets is small, about the size of a white potato; in shape round, rather than oblong, and is dry and mealy when cooked. DIB FERTILIZERS This characteristic of the crop is influenced both by the character of the soil and of the manures and fertilizers applied. The soils best adapted are dry, sandy loams, and the most useful fertilizers are those which contain an abundance of minerals,—phosphorie acid and potash,—and not too large supplies of quickly available nitrogen. It is also true that the yields of sweet potatoes of this character are not as large as those that may be obtained when quality is not a prime consideration, and which are grown for the general market. Fertilizer Constituents Contained in an Average Orop This crop is very similar to the white potato in regard to food required. Two hundred bushels of sweet potatoes, not including vines, contain, on the average, 30 pounds of nitrogen, 10 of phosphoric acid and 45 of potash; and since the yield of the general crop is larger on the average than one of white potatoes, a liberal supply of the minerals must in all cases be provided. The studies made of this crop have not yet established the best proportions of the constituents in fertilizers, though such experiments as have been conducted show that those that contain a very considerable excess of potash over the other elements are preferable. While nitrogen is needed, too much, particularly in soluble forms, seems to encourage too large a growth of vine, which con- tributes to yield, but at the expense of quality, which is a very important consideration. The best growers PROFITABLE FERTILIZATION 225 use fertilizers containing a small percentage of nitro- gen and a high percentage of phosphoric acid and potash. Applications that furnish 20 pounds of nitro- gen, 50 of phosphoric acid and 80 of potash per acre have given excellent results in regions in New Jersey in which market quality up to a certain point is quite as important as increase in yield, though, of course, yield is also considered. Any excess of nitrogen over this amount seems to contribute toward a larger, rather oblong, rooty growth of tuber, and to injure cooking quality. In growing crops for the general market, however, larger applications of nitrogen are demanded, and experiments have shown that organic forms are preferable to soluble forms, though the climate and season largely influence this point. In northern sections, and in cold seasons, the soluble forms are more useful than in the warmer climate and longer seasons of the South. There is no question, however, that commercial fertilizers can be depended upon to produce maximum erops of sweet potatoes, and at much smaller cost than with yard manure.* Results reported by the Georgia Experiment Station? indicate the following formula as an excellent one for sweet potatoes, though, as there stated, “the amounts that can be used vary considerably, depending upon the character of the soil—the richer the land in humus. the greater the quantity that can be safely used.” “Thin soils will, of course, only stand very moderate manuring, * Bulletin P, New Jersey Exp. Sta. t+ Bulletin No. 25, Georgia Exp. Sta. 224 FERVILIZERS and necessarily produce a very small yield.” The formula consists of — Acid Phosphate jee ay isu) a Menon, weree las 320 Ibs. Cotton seed MBA y/2) waite) seeitiente deal cud SOO BRITE i ty aii titer ala Ne su tinamem hres eater es 640 *S This formula will furnish about 25 pounds of nitro- gen, 50 of phosphoric acid and 80 of potash, and, according to the bulletin, will produce a yield of potatoes of from 200 to 400 bushels per acre, depend- ing upon the season and variety of potatoes planted. Experiments at the Georgia Station also show that organie nitrogen (cotton-seed meal) is preferable to nitrate of soda as a source of nitrogen. In making mixtures which furnish these propor- tions of plant-food, other nitrogenous organic ma- terials, furnishing an equivalent of nitrogen,—as blood or concentrated tankage,—may be substituted for the cotton-seed meal, if they can be purchased cuite as cheaply; and muriate of potash, furnishing an equiva- lent of potash, may be substituted for the kainit, if it can be more readily obtained. As already stated, however, this fertilizer is too rich in nitrogen for the production of the best quality of potatoes, as for example “Vineland Sweets,” which command the highest prices in northern markets. The growers in that district use a fertilizer richer in the minerals; one containing — Nitropenvic Ciuermer ae ukeiite 48 esata 3% PHOSPUOTIC: GCIG) i) ger hein iis an ee nes ee 7 % Potash ii oe weno hora me me 12 % APPLICATION OF FERTILIZERS 295 is very generally used, though reasonably heavy dressings of this are often further supplemented by applications of from 200 to 3800 pounds of acid phosphate and 100 to 150 pounds of muriate of potash per acre. The Application of the Fertilizers Owing to the fact that the sweet potato is grown from plants or slips, rather than from seed, and the fact that the best quality of potatoes is produced upon rather light, sandy land, it is desirable that the fer- tilizer should be applied some time before the putting out of the plants. The practice on this light land is to apply the fertilizer when making up the hills, which usually occurs from two to three weeks before the plants are set. That is, in making up the hills, the soil is ridged, and during the preparation of the ridge the fertilizer may be distributed in it and well mixed with the soil. Where the land contains more clay and humus if is frequently advocated that the potash manures be applied broadeast the previous year, and only the nitrogenous fertilizer and superphosphate be applied immediately to the plant. On soils of this latter character, this is doubtless the best system. If kainit,—which has been found to be preferable to mu- riate in the Georgia experiments referred to,—is used as the source of potash, it is very necessary that it be well mixed with the soil before setting out the plants. Heavy applications of this salt in the spring proved injurious in the experiments conducted at the New 0) 226 FERTILIZERS Jersey Station.* The effect of fertilizers upon the chemical composition of the tuber was chiefly to reduce dry matter, and not apparently to affect edible quality, though the experiments were carried out upon the general crop rather than upon those grown for high quality. TOMATOES Tomatoes are largely grown as a field crop, and the object of their growth, whether for the early market or for the canneries, is a factor that must be considered in the adoption of systems of fertilization. Field Experiments with Fertilizers for Tomatoes The impression is very prevalent among growers that the tomato does not require heavy manuring. Studies made at a number of experiment stationsT show, however, that the tomato is a plant that quickly and profitably responds to the use of manures or ferti- lizers, and that the maturity and yield are very largely influenced by the method of manuring and fertilizing. Experiments were conducted by the New Jersey Station upon three farms located in different parts of the state, and during four seasons, the object of which was to test the effect on maturity and yield of the early crop * Bulletin P, New Jersey Experiment Station. } Bulletins Nos. 21 and 32, Cornell Experiment Station (Ithaca). Bulletin No. 17, Georgia Experiment Station. Annual Report for 1891, Maryland Experi- ment Station. Bulletin No. 11, Virginia Experiment Station. Bulletins Nos. 68, 79 and O, and Report for 1892, New Jersey Experiment Station. THE NEW JERSEY EXPERIMENTS DONG, of the use of nitrate of soda in different quantities and at different times, both with and without the ad- dition of the mineral elements, phosphoric acid and potash, and to make a comparison of these with barn- yard manure. The results showed: First. That nitrate of soda was one of the best nitrogenous fertilizers for this crop, and that its use in small quantities (160 pounds per acre), or in large quantities (320 pounds per acre) in two applications, increased the yield materially, but not at the expense of maturity, and that this was equally true when used alone and when used in connection with phosphoric acid and potash. Second. That nitrate of soda, when used in large quantities (820 pounds per acre) in one application, in the presence of a sufficient excess of phosphoric acid and potash, did increase the yield, but at the expense of maturity. Third. That when properly used, nitrate of soda was a profitable fertilizer for the crop. It was shown, furthermore, that nitrate of soda was superior to both barnyard manure and mineral ferti- lizers alone, and on the whole, was but slightly less effective than the complete fertilizers. Fertilizers for the Early Crop for Different Conditions of Soil These results have been practically confirmed both by the experiments of the stations referred to, and also in actual practice on soils similar in character ; 228 FERTILIZERS namely, those which were well adapted for the early tomato — light, well-drained sandy loams—and which had been previously well manured for crops entering the rotation. The results do not apply in the case of very poor soils, or upon heavy elay soils, which are not adapted for the early crop. The statement that it pays to fertilize early toma- toes, and that nitrate of soda is one of the best ferti- lizers for the crop, must, therefore, be accompanied by statements regarding the condition of soil and the purpose of growth. With the conditions clearly under- stood, a scheme of fertilization for early tomatoes may be outlined which, when the conditions are observed, will be likely to give much better results than methods of fertilization which do not take into consideration the habits of the plant and the special object of its growth. For example, on soils which have been well sup- plied with the mineral elements, phosphoric acid and potash, by previous manuring or fertilizing, a ferti- lizer very rich in nitrogen derived from nitrate of soda, or nitrate of soda alone, should be used; the application at the time of setting the plant to be equivalent in nitrogen to from 80 to 100 pounds of nitrate of soda, with a second application of an equiv- alent amount made from three to four weeks later. A single application of the amount here suggested at the time of setting the plants would, perhaps, under good seasonal conditions give results quite as good, though the heavier application of nitrate at one time may result, in certain cases, in the loss of nitrogen FERTILIZATION OF THE EARLY CROP IID by leaching, since it is an extremely soluble salt. In this case a deficiency of food would result, and thus prevent the normal development of both plant and fruit. On soils which possess only good mechanical con- dition, and are very poor in plant-food, a heavier application of both nitrogen and the mineral elements will be required, in which case the following fertiliza- tion is recommended : Previous to setting the plants, or at the time they are set, apply 50 pounds per acre of phosphoric acid, preferably derived from superphosphate, and 100 pounds of potash, derived from muriate, and thor- oughly harrow or cultivate into the soil; and at the time of setting apply around the hill 100 to 150 pounds per acre of nitrate of soda. Three to four weeks later, make another application of from 100 to 150 pounds per acre of nitrate of soda. Owing to the small bulk of nitrate, it should be mixed with dry soil or sawdust, in order to insure even distribution. The only precaution to be observed is to prevent its immediate contact with the plant roots. If these methods are practiced, the plant secures its nitrogen in an immediately available form at a time when it is needed,—when it is set in the field. There is thus no delay in growth, and because of the presence of an abundance of the mineral elements no ex- cessive growth of vine is encouraged by the use of the nitrate, as would be the case were the mineral elements absent. Inasmuch as the nitrogen is ap- plied close to the plant, it is within the immediate 930 FPURTILIGHRS reach of its roots; and because it is all in an im- mediately available form, which is used up rapidly, the tendency to late plant growth, which would be caused by a continuous supply of nitrogen, is not en- couraged, and a normal and rapid growth and de- velopment of fruit results. It is not stated that by this method of fertilization maturity is increased in the sense that the date of the first picking is earlier, but that a larger number of fruits is picked earlier. It was not shown in any of the experiments that the date of picking was made earlier by virtue of the nitrate, for, in fact, the earliest tomatoes were picked upon land where the minerals only had been applied. Here the yield was not satisfactory, but where the nitrate was applied, because of the larger crop, a larger proportion of early tomatoes was secured. It is obvious that, in- asmuch as the price of the fruit rapidly declines as the season advances, receipts from the proportionately larger quantity of early fruit will be materially increased. The Use of Fertilizers with Yard Manures When it is desirable to use yard manures with fer- tilizers for tomatoes, because of the abundance and cheapness of the former,they should be applied broad- cast, and the nitrate applied at the time of planting, as already described, rather than both together in the hill. The tendency in the latter case will be to cause a loss of nitrogen from the nitrate, depending upon the FERTILIZATION OF THE LATE CROP Oil amount of organic matter in the manures. That is, experiments and experience have shown that under these circumstances more or less of the nitrogen in the nitrate may be lost. In the use of yard manures for early tomatoes, the application of excessive quantities should be avoided, as they are virtually nitrogenous manures, which, because of their organic character, feed the plant in proportion to their rate of decay. Hence, the presence of large quantities will encourage not only an undue growth of plant, but a late growth as well. The mineral fertilizers, as acid phosphate and muriate of potash, can be used with the yard manures with perfect safety, in fact, with great advantage, because supple- menting their proportionate lack of the mineral con- stituents. It is also desirable, where it is the practice to use manure, particularly if it is coarse, to spread it during the winter, in order that the soluble portions may become thoroughly distributed throughout the soil. As soon as the land is ready to work in the spring, it should again be plowed shallow and then deeply tilled, in order both to thoroughly warm up the soil, and to incorporate with it coarser portions of the manure. Fertilizers for Late Tomatoes In manuring and fertilizing for the late crop, the character of the crop and the season of its growth should be remembered. In the first place, the plants for this crop are not put in the soil until summer, when the conditions are most favorable for the rapid change Doo FERTILIZERS of organic forms of nitrogen into nitrates. Thus, if the soil has been manured or is naturally rich in vege- table matter, the additional application of nitrogen in immediately available forms is not so important. In the second place, the object of the growth is not early maturity, but the largest yield of matured fruit; hence it is more desirable to grow a larger plant than in the ease of the early tomatoes. The fertilization should, therefore, be such as to furnish an abundance of all the elements of plant-food; and, inasmuch as the tomato belongs to the potash-consuming class of plants, any fertilization should be particularly rich in this element. It is not to be understood, however, that it is not necessary to apply nitrogen, for frequently soils are used that are either not well adapted for the plant or are poor, not having been previously well supplied with vegetable matter containing nitrogen. On such soils, additional applications are very important, and nitrate of soda is one of the best forms to use, as it is absorbed freely by the roots, encouraging an early and vigor- ous growth of plant and a normal development of fruit. Slow-acting organic forms of nitrogen, on the other hand, frequently begin to feed the plant and cause its rapid growth when the energies should be concentrated in the growth and maturity of fruit. Fertilizers that have proved very excellent are those which contain a relatively smaller amount of nitrogen than is required for early tomatoes, and are richer in phosphorie acid and potash. A study of the composition of both the fruit and vine of the tomato will serve to guide us in this COMPOSITION OF FRUIT AND VINE 933 respect, though the amounts and proportions of food removed by any crop are not absolute guides, inas- much as the soil may furnish more of one constituent than another, and because the plant may have the power of acquiring certain of its constituents more readily than others. The analyses of the fruit and vines of tomatoes show that one ton contains: eae clear Acid Tash Inearait were a el i 3220 1.00 5.40 Vines (green). . . 6.40 1.40 10.00 Ten tons of the fruit, with the accompanying vines, which would probably reach four tons, would contain 57 pounds of nitrogen, 16 of phosphoric acid and 94 of potash. On a good soil, therefore, which without manure would produce five or six tons, there should be added a sufficient excess of the constituents to provide for a maximum _ production, and the materials should be relatively richer in nitro- gen and potash than in phosphoric acid. A mixed fertilizer composed of : INIbrs On OieSOd ays) li varisujeme Melia alee: 400 Ibs. Bane ihren ee nye y's 62) ay sities auaben, de ananele 700 ‘* AGIA ROS PALE! ('s),(6') ieee dle naan ling 400 ‘‘ Muriate, of potash 4 ho cia. asus vanes BOO Wan, would contain, approximately, 95 pounds of nitrogen, 144 of phosphorie acid and 250 of potash in each ton. An application of 500 pounds per acre of this mixture would furnish half as much nitrogen as is contained in a crop of ten tons, nearly as much immediately available phosphoric acid, and two-thirds as much 234 FERTILIZERS potash. Hence a dressing containing the amounts, kinds and proportions of plant-food here shown would be regarded as very desirable, since one-half of the nitrogen is in the form of a nitrate, which would contribute to the immediate growth of the plant. The amount of soluble and available phosphoric acid is sufficient to satisfy the needs of the crop throughout its entire growth, and such an abundance of potash as to contribute to the normal development of both plant and fruit. Formulas of this character have been used with good results, though the large pro- portion of salts sometimes make mixtures of this sort too moist to handle well, in which case a part of the potash, or even of the nitrate, may be applied separately with advantage. On poorer soils, the arti- ficial supply of plant-food should be proportionately greater, or sufficient to provide for the entire needs of a fair-sized crop, since as a rule the relative power of the plant to acquire food is somewhat slighter on poor soils than on good soils; or, stated in another way, the results from the use of fertilizers are pro- portionately better upon soils in good condition than upon those not well cared for. A good formula for these may consist of: Nitratevof Soday.cit dss «6 been een 500 lbs. Bone tanksgse xo 6s. ee ea aS 500. ** Acids phosphate: ia a fs ccee wes eee, con 400 ‘‘ Muriate of potash: iyo ia cae 2! eo gee 600 ‘‘ One ton of this mixture would furnish, approximately, 105 pounds of nitrogen, 120 of phosphoric acid and 300 of potash. The application of 1,000 pounds, NEED FOR NITROGEN REDUCED 255 therefore, would furnish the food in sufficient abun- dance and in good proportions to meet the demands of a fair erop. The advantage of using so large a proportion of nitrogen in the form of nitrate of soda in this case is, that it is immediately available, inducing the im- mediate and rapid growth of plant, and preventing a too late growth by furnishing a minimum of organic nitrogen, which would become available late in the season. The cost of the fertilizer suggested in these eases is high, and the necessity of so expensive a dressing could be materially reduced by decreasing the need for nitrogen, particularly in organic forms, which may be accomplished by sowing crimson clo- ver with or after the previous crop of, say, corn or tomatoes. If weather conditions are favorable, crim- son clover may be sown in the tomato fields in August, after cultivation has ceased, or at the last cultivation, and a crop of clover grown which will provide nitrogen for the next year’s crop. This method is now practiced with advantage by many growers. The late crop, like potatoes and sweet pota- toes, is usually grown in rotations in which it is the chief money crop; hence the unused residue from fer- tilizers applied in large amounts, as here indicated, contributes largely to the economical growth of sub- sequent crops. SUGAR BEETS The purpose in the growth of sugar beets is to obtain the largest total yield of sugar per acre; and 936 FERTILIZERS inasmuch as the sugar content of the beet, as well as its right growth and development, is very largely influenced by the character of the fertilization, this matter becomes of very considerable importance, in view of the promising development of the sugar beet industry in this country. Thus far, information con- cerning the use of fertilizers is derived largely from the results obtained in other countries, where it has been a prominent crop, and where great attention has been paid to this factor in its production. The Demands of the Crop for Plant-food The sugar beet draws heavily upon the soil for the nitrogen and potash constituents. A minimum yield of 10 tons of topped beets contains 44 pounds of nitrogen, 20 of phosphorie acid and 96 of potash. On medium loamy soils, which by their character are well adapted for the growth of the sugar beet, heavy fertilization with potash, however, has not been found to be de- sirable; while on light soils, which are also well adapted for the crop, liberal manuring with potash becomes absolutely necessary. As in this erop, the object of the growth is to se- cure not primarily beets, but sugar, and since the sugar formation is not perfected until the absorption of the necessary food from the soil has been in large part completed, any fertilization which promotes a too rapid or too long continued growth has a tendency to reduce the percentage of sugar; and inasmuch as the matu- ration takes place largely in the months of early fall, FERTILIZATION OF SUGAK BEETS 2a the growth must be foreed early in the season. That is, it is essential that a large and rapid leaf zrowth be made early, in order that the food from the air may be acquired. It has been demonstrated that for this early and rapid growth of the beet, phosphoric acid is one of the most essential constituents, which explains the need for phosphoric acid in larger proportion than is indicated by the composition of the beet. The crop requires a considerably greater supply of phosphoric acid at this stage of its growth than other farm crops which are quite as exhaustive, and it is also evident that in order that the crop may obtain the phosphoric acid at this period, it must be soluble and immediately available; hence the larger portion of this element applied should be derived from superphosphates. In the matter of fertilization with nitrogen, the object of the growth must also be kept in view. An application which would encourage steady and continuous growth, rather than an early and rapid growth, while contrib- uting to a large yield, causes a reduction in the sugar content of the beet. Hence it is strongly urged by those who are in a position to give sound advice, that the early nitrogen fertilization should consist of the quickly available forms, nitrate or ammonia, and that the organic or slower-acting forms should not be applied in such excess as to encourage a late growth. Henee it is, that upon medium and light lands the use of commercial fertilizers has proved of greater service in the growing of this crop than the exclusive use of yard manure, and in such quantities as to supply the entire needs of the plant. In the use of fertilizer, not 238 FERTILIZERS only the total supply of the constituents, but their form, may be regulated to the needs under different conditions, thus permitting a full feeding of the plant, and at a time most suitable to accomplish the object in view,— advantages which are not possessed by the natural manures. A fertilization which would meet the needs both in respect to quantity and kind of fertilizers, may be as follows : On good soils, the application or a fertilizer con- taining from 40 to 50 pounds of nitrogen, from 50 to 60 of phosphoric acid and from 40 to 50 of potash, would be sufficient to meet the demands of the plant. The nitrogen supplied should be derived largely from nitrates or ammonia, or both, and the phosphoric acid from a superphosphate, while the potash may be de- rived from sulfate or muriate of potash. The former is preferable if applied during the spring preceding the planting of the beets. While it is frequently desirable, for convenience and economy of labor in applying, that the fertilizer should be mixed, in order to prevent any waste of soluble nitrogen, it should be applied in fractional dressings. For example, a mix- ture of 250 to 800 pounds of nitrate of soda (or, the nitrogen may be derived partly from nitrate and partly from ammonia), 400 to 500 pounds superphosphate, and 80 to 100 of muriate or high-grade sulfate of potash, should be applied in two or three dressings. A part only should be applied previous to sowing, for both the nitrate and the potash salts have a depress- ing effect upon germination. They are preferably ap- ADVANTAGES OF DEEP CULTIVATION 939 plied, say, one-third of the mixture as soon as the plants have come up, another third immediately after or before the first cultivation, and the remainder immediately after or before the second cultivation. The application of the fertilizers in these forms and at the times indicated insures the rapid and early growth and development of the plant; and by reason of the solvbility of the nitrates and ammonia salts, a late feeding of the plant with nitrogen is obviated. On light or medium soils, the amount of plant- food should be increased by at least one-third, though fractional applications should be made as previously recommended. On soils rich in vegetable matter, a part of the nitrogen may be omitted, though the phos- phorie acid should not be reduced. The Influence of Previous Deep Cultivation of Soil Another point to observe in the growing of beets for sugar,—and it also has an immediate bearing upon fertilization,—is the character of the previous cultiva- tion. If the soils have not been deeply and well eulti- vated, so large a dressing as is here recommended would be likely to be deleterious, as with a shallow and poorly prepared soil plants would have less op- portunity to penetrate deeply, and thus too great a growth above the surface of the ground would be encouraged, with a consequent lowering of sugar con- tent as well as yield. The best practice in our country will have to be developed by the experience of our own growers, 940 FERTILIZERS though in the absence of such experience, the recom- mendations here made may be relied upon. In many of the sections of this country in which the soils and climate are well adapted for the sugar beet industry, the needs as yet are quite as much for improved methods of cultivation as for added fertility. They have not been exhausted of their essential elements of fertility. An epitome of the soil conditions for sugar beet culture will be found in the second edition of Roberts’ “Fertility of the Land,” p, 400. CHAPTER XII GREEN FORAGE CROPS A LARGE number of crops is included in this elass. In dairy districts they are grown for summer feeding, mainly to supplement or to entirely substitute pas- turage, as well as to provide a succulent ration of roughage in winter. Any crop which grows quickly, is palatable, and makes a reasonably large yield, is adapted for the purpose. For convenience of study, these crops may be further classified into three groups : 1. Cereals and grasses. 2. Clovers and _ other legumes. 3. Roots and tubers. In the case of those included in the first group, the purpose or object is to obtain as large a growth of leaf and stem as possible. Thus the character of the fertilization may differ from that recommended when the same crops are grown for the primary purpose of obtaining the largest yield of seed or grain. These erops, too, may in all cases be considered as only well adapted for the “intensive” system of practice—that is, when the management is such as to encourage the largest yield possible per unit of area under the ex- isting conditions of climate and season. ‘I'he natural fertility of the soil thus becomes a less important factor; indeed it cannot be relied upon altogether, as P (241) 242 FERTILIZERS the largest yield of succulent food is dependent upon a rapid and continuous growth, and hence the supply of plant-food must be relatively much greater than is the case when the cereals are grown for their seed. That is, forage crops, because succulence is a factor influencing quality, must, as a rule, be grown quickly, and in order that large yields may be obtained in a short period of time a relatively greater abundance of plant-food must be at their disposal than when the growth is distributed through a longer period. Be- sides, larger amounts of all of the food constituents are required for the production of the same amount of dry matter per acre than when grown for the mature erop, because the dry matter of the mature crop is richer in the constituents derived from the air and poorer in those derived from the soil, than the dry matter of the immature crop. Maize (Corn) Forage _ A valuable forage crop of the first group is maize (Indian corn), because it grows quickly, is well adapted for a wide variety of soils and climates, is extremely palatable, and is capable of producing large yields. The fertilization which has been recommended for the field crop is less desirable than one which furnishes a greater proportion of nitrogen, because of the greater need of this element, and because it encourages a larger leaf and stalk growth; and the greater the pro- portion of these in a corn erop the richer will be the dry matter in the important compound protein, and FERTILIZERS FOR CORN FORAGE 943 nitrogen is the basic element in this group of nu- trients. When the crop is grown on good land on clover sod, which has been liberally manured, the fertilizers applied should be particularly rich in the mineral elements, phosphoric acid and potash. An application of 500 pounds of a mixture containing— INI EO SSMS ist NOS LANE RE teal) a 2% Available; phosphoric: acid, )'.)/).) 4) .))2) 25,5). 6 % Pokash Pie RAN ey sl MRSA. SAS UN AES 8% would provide an abundance of food, even should unfavorable conditions intervene, but when grown on light, unmanured soil without sod, a larger amount of nitrogen should be used in connection with the min- erals. An application of 25 pounds of nitrogen, 35 of phosphoric acid and 50 of potash is as small a fer- tilization as should be recommended on soils of this character, since a yield of 10 tons per acre, containing 25 per cent of dry matter— which is only a fair crop —would remove 60 pounds of nitrogen, 25 of phosphorie acid and 70 of potash. Hence, very large increases in yield could not be expected from smaller dressings, unless conditions were absolutely favorable throughout the entire period of growth. The nitrogen, as in the ease of field corn, may be derived from organic sources, as the season of growth is the same—the summer—which is the most favorable for encouraging a rapid change of the organic nitrogen into the soluble nitrates. The phosphoric acid should be in large part derived from superphosphates, though since the season of growth 944 FERTILIZERS and the character of the crop and of its cultivation are conditions all of which favor a rapid change of in- soluble into available forms, a portion may be sup- plied by ground bone or tankage. The potash may be kainit or muriate, though if kainit is used, it should be broadeasted and well worked into the soil before planting. Silage Corn Corn grown for the silo, while distinctly a forage crop, is, in its management, very similar to the field crop, and is not planted so thickly as to prevent the formation of ears. The object in its growth is, how- ever, to obtain a large yield of dry matter, somewhat richer in nitrogenous substance and poorer in starch and woody fiber than field corn. Hence the fertilizers for the crop on medium soils should be richer in nitrogen than for the field corn, where the primary object is the grain, and where heavy fertilization with nitrogen would encourage a disproportionate stalk growth. An application of 30 pounds of nitrogen (equivalent to 250 pounds of dried blood or 450 of cot- ton-seed meal), 40 of phosphoric acid (equivalent to 300 pounds of acid phosphate), and 60 of potash (equivalent to 120 pounds of muriate of potash), would provide for a marked increase in yield. Wheat and Rye Forage In the growth of cereal grains, the object is to secure as large a yield of grain as is possible under WHEAT AND RYE FORAGE 245 the conditions of climate and season, and only such development of leaf and stem as will contribute to a maximum yield of grain. Hence a too liberal nitrog- enous fertilization which encourages this form of growth may result in too great a proportionate yield of straw. This objection becomes an advantage when the cereals are grown for forage. The cereal crops, wheat and rye, if seeded in the fall, should, therefore, receive a fertilizer which shall especially promote leaf and stem growth; and to ac- complish this purpose in the best manner, a rapid early fall growth, and a consequent deep rooting system, as well as an early and rapid spring growth, should be encouraged. Fertilizers most suitable are rich in nitrogen and phosphoric acid, and should contain potash also, if the land has not been previously well supplied with this element. The larger proportion of the nitrogen, however, should be applied in available forms as a top-dressing in the spring, rather than at time of seeding, thus reducing the possible loss of this element during the winter and early spring through leaching, besides providing the plant with it when most needed, and producing a crop richer in nitrog- enous substance. The ranker growth and somewhat coarser product resulting from this method of fertilization, while not desirable for grain crops, is not a detriment when the product is cut in its green stage for feeding, and the larger growth is accompanied by greater succulence. Where these cereal grains are sown mainly as eatch crops following a corn crop which has been 246 FERTILIZERS liberally fertilized with the minerals phosphoric acid and potash, the application at time of seeding may be light, and may consist only of nitrogen and phosphoric acid,—for example, from 200 to 400 pounds per acre of a dissolved bone; and the top-dressing in the spring need not exceed 100 pounds of nitrate of soda per acre for the wheat, and 75 pounds per acre for the rye. For lighter soils, or for those not previously well fer- tilized, much heavier applications not only are required, but all of the constituents should be ineluded, and the top-dressings should be made in spring, as already pointed out. Spring Rye For spring rye, an application of a fertilizer fur- nishing 10 pounds of nitrogen, 20 of phosphoric acid and 10 of potash per acre would be a sufficiently liberal dressing for the crop on good soils, since the plant possesses good foraging powers, though it is not so desirable a forage crop for northern climates as the winter rye. The nitrogen, in any case, should be in quickly available forms. Oats Oats and millet are also suitable crops for forage purposes, and are largely grown; the first, because it is adapted for cool, moist weather, and makes a rapid early growth, and the second, because adapted for late spring seeding and for summer conditions. The oat crop for forage purposes is even more A PECULIARITY OF THE OAT CROP 947 generally benefited by manuring than when grown for the grain, and the constituents particularly useful are nitrogen and phosphoric acid, though on sandy soils, and on those of medium fertility and not previously fertilized with potash, this element should also be added. A good dressing, keeping in mind the value of the possible inereased yield, may consist of 12 pounds of nitrogen, 20 of phosphoric acid and 10 of potash,— the nitrogen largely in the form of a nitrate and the phos- phorie acid in soluble and available forms. The oat crop is peculiar in that shortly after the germination of the seed, there usually occurs a period of a week or ten days during which the growth is ex- tremely slow, which experienced farmers call the “ pout- ing” period. While the exact cause of this well-known habit is not understood, it is believed to be due in part to the absence of available plant-food of the right sort early in the season, since liberal applications of nitrates and superphosphates seem to shorten the period of “pouting,” if not altogether preventing its occurrence. Its avoidance for grain crops, while im- portant, is not so important a matter as in the case of forage crops, since an extension of the period of growth simply delays ripening, while in the latter, delays not only prevent maximum growth within a certain time, but seriously interfere with rotations. Winter oats, which are successfully grown in the southern sections of the country, should be fertilized at time of seeding practically in the same manner as wheat; that is, dressings furnishing small amounts of 248 FERTILIZERS nitrogen and considerable phosphoric acid, to be fol- lowed in spring with a top-dressing of nitrate of soda, not to exceed 100 pounds per acre. Oats and Peas Where oats are grown with field peas for the pur- pose of supporting the vines, as well as to obtain a larger yield than from either alone, the fertilizer should also contribute toward the increase in the pea crop, and hence a greater abundance of the minerals should be applied, though it is very desir- able in this case, too, to encourage the rapid growth of the oats by reasonably liberal supplies of available nitrogen. Barley and Peas The growth of this combination of plants is a desirable one when late fall forage is needed, and as a crop is well adapted for fall conditions. The ferti- lization should be liberal, in order to encourage a rapid and large appropriation of food, which may be elaborated after light frosts occur. An application of 200 pounds per acre of a mixture of 100 pounds of nitrate of soda, 175 of acid phosphate and 25 of muriate of potash, will furnish sufficient and good proportions of the plant-food constituents. Millet The various kinds of millet are eminently sur- face feeders, and are particularly benefited by lberal THE FERTILIZATION OF MILLET 249 applications of all the fertility elements. In fact, maximum forage crops of this plant cannot be ob- tained except when there is present in the soil such an abundance of all of the fertility elements as to enable a continuous and rapid growth. Both the nitrogen and phosphoric acid should be largely in immediately available forms; hence nitrates and super- phosphates are recommended. The potash may be in the form of muriate.