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Show ' " !! I M ..I.. ll I HOME COURSE IN SCIENTIFIC AGRICULTURE FOURTEENTH ARTICLE. COMMERCIAL FERTILIZERS. FER-TILIZERS. By EDWARD D.VOORIIEES.Lale Director of (lie New Jersey Agricultural Experiment Stations. THERE Is perhaps no 'question of greater Importance to tho practical farmer than that of soil fertility. To produco prof-ltnbjo prof-ltnbjo crops and at tho Bume tlmo to maintain and oven to increase the pro-ductlvo pro-ductlvo capacity of tho soil may rightly bo termed "good farming." Many farmers aro ablo to do this, and the knowledge of how to do It bus been largely acquired through years of experience, ex-perience, during which tho character of tho soil, its adaptability for crops and tho 'methods of Its management and manuring have been mudo subjects sub-jects of careful study, without, however, any definite and accurato knowledge concerning manures and their functions func-tions in relntlon to soils nud crops. Experleuco is an excollcnt teacher. Still a definite knowledgo of tho fundamental fundamen-tal principles may be subsUtuted for years of experleuco in tho successful uso of manures. Tho fertility of tho soiLwould remain re-main pracUcally unchanged if all tho ingredients removed in tho various farm products wero restored to the land. This is to a largo extent accomplished accom-plished by feeding tho crops grown on tho farm to animals, carefully saving the manure and returning it to the soil, and whero it is pracUcablo to pur-buo pur-buo a system bf stock feeding In which thoso prodnctn of tho farm which are comparatively poor In fertilizing constituents con-stituents aro exchanged In the market for feeding stuffs of high ferUllzlng valuo tho loss of soil fertility may be reduced to a minimum, or tbero may bo an actual gain in fertility. A careful study of tho present condition condi-tion of farming in tho United States indicates, in-dicates, however, that as a rule the manure produced on tho farm is not sufficient to maintain Its ferUlity and that the need for artificial supplies ic real, though tho amount required may bo considerably reduced by careful management In the system of so calledv "grain farming," which has obtained ovet large areas of this country for a long time and is etlll practiced, the llvt stock in often limited to a number sufficient suf-ficient only to the. needs fif ifflfli '---for labor and iobdr Tho g'foln Is sold, and the manure is made up chiefly of thfe natural wastes or unsalable material, ma-terial, such as straw, stalks, etc. The grain contains proportionately greatet amounts of nitrogen and mineral constituents con-stituents than these wastes. Hence thr practice conUnucd for a long time results re-sults not only in a deficiency in the soil of organic substances containing nitrogen, nitro-gen, but also in an exhaustion of the mlnoral substances. Tho original character char-acter of the soli and Its treatment mcasuro the rato of exbausUon. The less ferUIo soils of the cast and south aro rapidly depleted, wlitlp the rich prairies and river bottoms mnintaii: their fertility for a longer period. Tho continuous cotton and tobacco growing of the south and tho wheat growing of tho west aro even moro exhaustive, slnco hero tho demands upon the soil aro not changed. Year after year tho sumo crop Is grown, and tho samo kind and proportion of "constltueuts aro required, whllo oyeq slighter returns nro mado in the way of mauuro than In the system of farming farm-ing just described. Under quel) con' dltlons tho decomposition of tho or ganic matter in tho soli Is accompanied accompa-nied by proporUonately greater losses of nitrogen. Moreover, tho land is left baro fp u large part of tbo year, uud Its fertility Is thoroby still further do creased. Tho crops become leds abundant abun-dant each year, not becnuso tbo soil ii entliely exhausted, but because it Is so far exhausted of thoso constituent esBonUal to tho special crop grown that Its production Is no longer profitable Changed conditions of farming, Which havo an important bearing on this point, aro, first, increased cost oi labor and lowor prices of many of the products of ouo crop farming, nndt second, an Increasing dotnand for market mar-ket garden products and fruit. Foi oxampl.o, In growing wheat, tbo laboi of preparing tho soil, of sowing and ol harvesting is practically tbo same, whether tho yield la ten bushels poi aero or thirty bushels, and tho same it true of a number of other crops; benc in cjiso of tho largor yield tho cost oi labor per bushel Is materially reduced. Meager crops of n relaUvoly low value cannot bo produced profitably with high priced labor. Soils of n high do grco of fertility nro required In ordoi to produco largo yields of theso crops Tho return to tho soil of only the wastes of tho farm leads sooner oj later to n decreased fortuity, howevei good tho management mny bo; hence tho need of supplies of plant food from sources outside the farm In order that maximum crops may bo produced. It has been demonstrated in tho cast of market garden crops that even vorj fertllo soils contain too llttlo avallablt food to insure a maximum production This Is especially truo whom rapidit of growth, oarliuees and high quallt) of produce an Important factors. Tho ureas now, necessarily dvotel to theso crops are w Rreat that th amount of farm manures available Is much too email Beidos, the constituents contained con-tained In such manures, being In part but slowly available, are lees useful than the more active forms contained in commercial fertilising materials. Market gardon -crops are In a sense artificial crops and, as a rule, need artificial supplies of plfint feod. Fruit culture, an lndus'try of growing grow-ing Importance, Is profitable, particularly particu-larly on the poorer soils near tho eastern east-ern markets, largely In proportion to tho amounts of the mineral elements applied In excess of those contained in soils otherwise well adapted to the crops. A proper supply of food not only enables tho trees to resist unfavorable unfa-vorable conditions, btlt Improves the quality of tho fruit and. prolongs tho benrlng period of tho orchards and vlnoyards. It will bo thiis sCeir thrtt commercial fertilizers can bo used most ndvan-1 tagcously cither in re-oiiforclng farm mnnurcs In general or in providing a generous supply of quickly available plant food in specialized, intensive farming. It should be iho aim in applying ap-plying Bitch fertilizers to supplement rather than tn mplnce entirely tho manurlal resources of the farm, for tbo best results from their application may bo secured only on soils well stocked with orgnnic matter (humus), a material that can bo maintained la tbo soil only by tho systemaUc application appli-cation of tho bulky barnyard or green manures. Nitrogen, phosphoric acid and potash aro tho constituents most likely to bo deficient in soils or most quickly exhausted ex-hausted by tho production and romovnl of crops. They nro known ns "essential" "essen-tial" ferUllzlng constituents, and tho valuo of a commercial fertilizer is determined de-termined nlmost exclusively by tho amount and form of the nitrogen, phosphoric acid and potash which it contains. It docs not follow, however, that all soils or crops will respond equally to applications of materials containing these elements, fpr the needs of soils and the requirements of crops vary. Soils differ as to their needs for specific ferUlity elements, owing cither ci-ther to their method of formation or to their management and cropping. A sandy soli is usually deficient In nil the essential plant food consUtuenU nitrogen, phosphoric acid and potash whllo n clayey soil usually contnjns tho mlnoral clcmonts in abundance, particularly potash. On tho otter hand, a soli very rich in vegetable matter Is frequently deficient In mineral min-eral matter, whllo a limestone soil i Is likely to contain considerable proportions propor-tions 'of phosphoric acid. j Theso aro the indications In n general gen-eral way, and they explain why lth that different kinds of soil that hare not been cropped differ as to thdr need of tho different fertilizing eje- stitucnts. . fm Methods ofymanagemeut nul ,ciM ping a.lgoexiytMalaauent!f.'iff6aWJ "tmpie, soils cf equal natural fertUp1 mlny not respond equally to unlfolE methods of fertilization, becauso k the ono case a single crop requiring for, Its growth proporUonately moro of one of tbo essenUal eloments than of another an-other is grown year after year, and it may bo that the element required 1b the ono that exists in tbo soil In least quanUty. On tho other hand, crops may be grown that demand but minimum amounts of the element in qucsUon. Summarizing tho conclusions of science sci-ence and pracUcal experience in regard to tho uso of commercial fertilizers, It may bo said: First Commercial fertilizers are mainly valuablo becnuso they furnish tho elements nitrogen, phosphoric acid aud potash which servo as food, not as sUmulants. Second. Thp kind of farming in the past nnd tho domnnds for special prou ucts in tho present make their uso necessary nec-essary In profltablo farming. Third. In order to uso them profitably profita-bly the farmer should know-fa) know-fa) That nitroget?, phosphoric aclfl and potash aro th.o essential manuriaj cqnBtituents. (b) That tho agricultural valuo of these constituents depends largely upon thoir chemical form. - (c) That theso forms nro contained in specific products of a woll defined chnractcr and composition and may bo purchased as such from dealers nnd manufacturers nnd may bo mixed sue-cesnfully sue-cesnfully on the farm. Fourth. Tho agricultural valuo of a ferUllzcr bears no strict relation to tho commercial valuo. The ono Is determined de-termined by soil, crop and cllmaUc coudlUons, tho other by market and trado conditions only. Fifth. Tho variations in the corapo-slUon corapo-slUon and valuo of manufactured fertilizers fer-tilizers which contain tho three cssen-tlal cssen-tlal constituents aro duo to variations In tho chnractor and in the proportion of tho materials used. Sixth. The ton basis alono Is not a Bafo guide in tho purchase of these commercial fertilizers. Low ton prices mean either low content of good forms of plant food or tho uso of pooret forms. Fertilizers, high grado both in quality and quantity of plant food, cannot bo purchased at a low price pet ton. Seventh. Tho best ferUlIzcrs cannot exert their full effect on soils that are too dry or too wot, too compact or too porous. They can furnish but one ol tho conditions of ferUlity. Eighth. The kind and amount to nut should bo determined by tho valuo oi tbo crop grown aud Its power of acquiring ac-quiring food. Ninth. A doflnlto system or plan should bo adopted, in tho use of fertilizers. fertili-zers. "Hit or miss" methods aro seldom sel-dom satisfactory aiid frequently verj expensive. ' ' t |