630.7 0k4b no. 32 cop. 4 NOTICE: Return or renew all Library Materialsl The Minimum Fee for each Lost Book is $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 Digitized by the Internet Archive in 2017 with funding from University of Illinois Urbana-Champaign Alternates https://archive.org/details/practicalchemist3218holt OKLAh^OMA Agricultural Experiment Station Bulletin No. 32-March, 1898. Practical Chemistry of Soils and Crops, A Study of the Castor Oil Plant, GEO. L. HOLTER, JOHN FIELDS Bulletins of this Station are Sent Free to Residents of the T erritory on Request STILLWATER, OKLAHOMA. OKLAHOMA AGRIOULTURAL AND MEOHANIOAL OOLLEGE. Agricultural Experiment Station. BOARD OF REGENTS, IKIN. C. M. BARNES, GovEKNOB, ex-offlcio, - HON. JOHN D. DEBOIS, PRESIDENT, HON. F. CARUTHE:RS, Treasukek. . . . . HON. R J. EDWARDS. HON. W. F. BORT. H(^N. DAl.E LYTTON, ------ Guthrie Guthrie Oklahoma City Oklahoma City Kingfisher Stillwater STATION GEORGE E. MORROW, M. A.. HENRY E. GL-\ZIER, - - - - GEO. L. HOLTER, B. S.. - - - E. E. BOGUE, M. S., L. L. LEWIS. M. S., D. V. M.. JOHN FIELDS, B. S.. J. H. BONE, B. S.. J. T. DeBOIS. STAFF. Director and agriculturist. Vice-Director and Horticulturist Chemist. Botanist and Entomologist. Veterinarian. Assistant Chemist. Assistant Agriculturist Cl.ERK Practical Chemistry of Soils and Crops, SUMMARY, 1. The fertility of every soil has a limit. Each crop g’rown removes a portion of the elements of fertility and leaves the soil poorer. 2. The staple crops of Oklahoma — wheat, oats, corn, kafir, cotton, and castor beans — if properly manag'ed will not quickly exhaust the soil. 3. The portion of these crops that is sold, when intelli- g-ently handled, removes less plant-food than does that irortion which is frequently wasted and which should be returned to the soil. 4. General farmin^q the g-rowing- of a moderate aci'eag-e of each of many crops, is to be prefeia*ed to the g-rowing^ of but one or two crops year after year. .). Stock-raising" and feeding* should be eng'aged in by every farmer who can possibly arrange to do so. Aside from the increased price thus secured for crops, this system of farm- ing- tends to keep the plant-food on the farm. 6. Stable manure is a valuable agent for the improvement of our soils, and should in all cases be well cared for and spread on the fields, and not be regarded as a nuisance to be disposed of in the easiest possible manner. 7. Castor bean pods contain a large amount of fertilizing constituents, are of fully as much manurial value as average wood ashes, and should be regarded as an important feature of the castor bean crop. INTRODUCTION. It should be the earnest endeavor of each owner of a farm to keep the original stock of fertility of the soil unimpaired, and, if possible, to so manage that an increase over previous yields will be secured rather than a continually diminishing return for the labor expended. That this may be accomplished, it is essential that the simpler facts of the chemistrv of soils and crops be familiar to every one engaged in farming. The — 4 — following’ pages have been prepared for the purpose of ac- quainting the farmers of Oklahoma with what is known along this line, and of clearly setting forth the relation of our prin- cipal staple crops to the soil’s fertility. The experience of the eastern part of the United States emphasizes the importance of this subject. The enormous sum paid annually for commercial fertilizers is, to a great extent, the penalty which must be paid for wasteful practices which were common when the “un- bounded fertility” of the soil w^as never questioned. PLANTS. Every plant, from the vilest weed to the most valuable crop that grows, is made up of essentially the same elementary sustances. Part of these substances are taken from the air and part from the soil. At present, for sake of clearness, no further reference will be made to that portion obtained from the air. More than a dozen different elements contained in plants are derived from the soil. It is needless for our present purpose to complicate matters by giving a list of them. All of them are essential to the production of plants and all are found in almost every soil. SOILS. Practically, every soil contains all of these substances, with three exceptions, in sufficient amounts for the production of maximum crops if the other conditions, such as water supply and mechanical conditions, are right. This being the case, it is sufficient for our present purpose to consider only the ex- ceptions. The three substances frequently deficient in soils are nitro- gen, potash, and phosphoric acid. These names have been as- signed to certain substances that are present in and essential to the growth of all plants. If one is absent from a soil, the crop will not mature properly; if any one of them* -exists in a very limited quantity, continually decreasing-crops will be the result. Nitrogen, potash, and phosphoric acid collectively are called plant-food, a term which carries its meaning with it. This plant-food exists in several forms in the soil; some of it is soluble, and consequently called available, because it is in a form to be taken up by plants. Other portions are insoluble and not ready for use. hence termed unavailable. The amount of available plant-food in a soil is the factor which determines its ability to produce a crop and the number of crops which it will produce. The available plant-food is slowly replenished from the insoluble portion, but at the same time it is being- diminished by crops and by the leaching- of the soil by heavy rains. This supply of plant-food is the stored-up energy of the farm. Different crops remove tliese^three materials in different amounts, but::each crop leaves the soil with a portion of its stored-up energy expended. SOIL ANALYSIS. This being true, it would seem that a chemical analysis of a soil should tell exactly the amount of plant-food which it contained and afford a means of correctly estimating its crop- producing power. This, however, is not the case. The difficulty of securing representative samples, inability to determine the exact amount of available plant-food, and the impossibility of correctly forecasting the rate of change in availability of the plant-food, make a soil analysis of little direct, practical value to a farmer. Climatic conditions being favorable, the only true test of a soil’s ability to produce a crop is a crop test. On the other hand, a study ofdthe amount of plant-food re- moved by different crops, and of the most profitable way of converting those'crops into money^and still retaining their ele- ments of fertility on the farm, is the true way for a farmer to conserve his] capital. Leading toward this end, Oklahoma’s staple crops have been studied and general plans of the way of disposing of them so as to reduce the loss of plant-food, by their sale, to a minimum are given in the following pages. WHEAT. One thousand pounds of winter wheat contain 24 lbs. nitro- gen, 6 lbs. potash and 9 lbs. phosphoric acid.* The straw harvested with this amount of grain will weigh approximately two thousand pounds, which contain 12 lbs. nitrogen, 10 lbs. potash and 3 lbs. phosphoric acid. The grower of wheat has no option but to sell the grain. *The commercial value of the elements of plant-food in farm crops is at present assumed to be the following per lb.: nitrogen, 12cts.; potash. .5 cts. ; phosphoric acid, 4 cts. These ngures represent what these materials would cost if purchased in the form of fertilizers to be applied to the soil. — I) — Present methods of disposing of the straw could be greatly im- proved. The straw is valuable not only on account of the plant-food which it contains but also on account of the large amount of organic matter. Many of our soils are hard and compact and would be greatly improved by plowing the wheat straw under, thus bettering their mechanical condition by mak- ing them take up water more readily and part with it by evap- oration more reluctantly. The straw, instead of being burned or allowed to decay in one huge pile, should be hauled or dragged over the field, scattered about and plowed under. It is true that decomposition of straw takes place but slowly in this climate, but the little extra trouble in plowing will be repaid b}^ the improvement of the soil wdiich will result. Where headers are used, much of the straw is left in the fields, but that which is removed should nevertheless be returned to the soil. The preceding remarks apply to farms almost exclusively devoted to raising wheat, and on which little stock is kept. On farms where a variety of crops is grown, the manure pro- duced by bedding the stock in stables, as well as that which accumulates when cattle winter about the straw pile, should be hauled onto the fields and plowed under when the soil is being prepared for a subsequent crop. OATS. One thousand pounds of oats contain 20 lbs. nitrogen, 12 lbs. potash and 16 lbs. phosphoric acid. The straw harvested with this amount of grain wfill weigh approximately two thousand pounds, which contain 12 lbs. nitrogen, 25 lbs. potash* and 4 lbs. phosphoric acid. The grain may be either sold or fed on the farm. At prices which usually prevail, it pays better to pursue the former course and feed corn or kafir. The remarks made concerning the disposal of wheat straw apply with equal force in regard to oat straw, with the excep- tion that the latter contains a larger amount of plant-food and its return to the soil is even more important. CORN. One thousand pounds of corn in the ear contain 14 lbs. nitrogen, 5 lbs. potash and 6 lbs. phosphoric acid. Approximately six hundred pounds of corn stover will be produced along- with this amount of corn. This weight of stover contains 6 lbs. nitrogen, 8 lbs. potash and 2 lbs. phos- phoric acid. By far the largest amount of corn grown in the Territory is husked from the standing stalks, which are left in the field and serve as winter pasture for cattle. It is, however, customary to drag off the stalks in the spring and burn them. This prac- tice has its commendable features, as it is very difficult to get the soil in good condition when it is littered with corn stalks. Notwithstanding this, the practice is a wasteful one and should be resorted to as seldom as possible. All of the nitrogen is lost when anything is burned, as well as the organic matter in which many of our soils are deficient. The disposal of the corn is accomplished in two principal ways, either by selling the crop direct, or by feeding it to cattle or hogs and selling them. From the standpoint of maintenance of fertility, the former method is undesirable. Better returns in money are usually secured and less depletion of the soil’s resources takes place when the corn is fed to stock and the manure returned to the soil. When any crop is fed to stock, less than 25 per cent, of the manurial value of the feed is carried off by the animals when they are sold. This being the case, farms where a sufficient number of animals is fed to con- sume the corn crop will, beyond question, be producing good crops of corn long after the farms from which the crop is sold every year have been abandoned. KAFIR. One thousand pounds of mature kafir fodder (whole plant) contain 8 lbs. nitrogen, 22 lbs. potash and 9 lbs. phosphoric acid.* For sake of comparison, one thousand pounds of corn fodder contain 12 lbs. nitrogen, 9 lbs. potash and 6 lbs. phosphoric acid. Under present conditions, the bulk of kafir grown is fed on the farm. This, as with corn, is the most desirable method of disposing of the crop. ^Calculated from but one analysis, samjjle No. 576; moisture, 7.53 per ct.; nitrogen, 0.76 perct. ; potash, 2.22 perct. ; phos. acid, 0.91 per ct. No analyses of kafir grain for fertilizer constituents are available. H (COTTON. There is no other crop that will, if improperly managed, more certainly diminish the fertility of the soil. The impover- ished soils of the old cotton-growing states are a more convinc- ing argument in support of this proposition than any arrange- ment of the results of chemical analyses could possibly be. Yet it may serve a useful purpose for us to examine the compo- sition of the cotton plant, that we may understand clearly why it Is so exhausting to the soil and how to avoid this exhaustion. One thousand pounds of ginned cotton contain 3^ lbs. nitro- gen, lbs. potash and 1 lb. phosphoric acid. With this amount of lint will be produced two thousand pounds of cottonseed, which contain 63 lbs. nitrogen, 23 lbs. potash and 25 lbs. phosphoric acid. If nothing but the lint is sold, and the seed is in some way returned to the soil, but very little diminution of the soil’s fer- tility will result, the lint containing but an insignificant amount of plant-food. The seed, on the contrary, is a concentrated substance which contains a large amount of materials whose removal impover- isnes the soil. Cottonseed may be disposed of in a variety of ways, chief among' them being (a) selling for an absurdly low price to gins, where it is sometimes used for fuel, thus entailing an enormous waste of nitrogenous matter; (b) selling to oil mills, where the oil is extracted and the cottonseed meal shipped to northern markets, carrying with it the fertility of our soils; (c) feeding the seed to cattle, or exchanging it for cottonseed meal at the oil mill and feeding the meal. Without losing sight of the fact that it is not always possi- ble to do the best thing from an economic standpoint, it does seem that the lesson of the old states should not be lost on this new country. At times it may be necessar}^ to sell the seed for what it will bring and use the proceeds for pressing necessities. This should, however, be the exception and not the customary method. The cotton-grower is very apt to become a “one- crop” man, and, if he does, the chances are that he will leave neither money nor a good farm to his children. The general results of feeding experiments with cottonseed are that it may be fed with profit to steers in connection with — II — our common forage plants, such as corn or katir stover. It is not considered safe to feed it to hogs, but bad results are not always experienced when hogs are allowed to run after steers that have been fed cottonseed. The building of oil mills should be encouraged and, when they are established, an exchange of cottonseed for cottonseed meal, which is the better feed, should be made instead of selling the seed. The meal is left after the extraction of most of the oil, and is an excellent feeding stuff in addition to its containing nearly all of the plant-food which was in the hulled seed. The feeding of cottonseed and its products to cattle by cotton-growers is the proper method of keeping up the fertility of our cotton-fields. Had this plan been followed by cotton-growers in the old South, they would not now be under the pressing burden of an enormous annual expenditure for commercial fertilizers. CASTOR BEANS. • An extended study of the castor oil plant has been made. Details not of direct, practical interest are given at the close of this bulletin. Since the leaves and stalks of this plant remain in the field, the plant-food which they contain returns in a great measure to the soil and need not enter into this discussion. The portion which is gathered when the crop is harvested consists of the pods containing the beans, together with the stems of the spikes. This is later divided into two portions, which we have designated respectively as beans, the part which is sold, and pods, which remain on the farm. One hun- dred pounds of the dry, gathered spikes yield, as the average of our determinations, 55 lbs. of cleaned beans and 45 lbs. of pods. The features of this croj) which deserve study are (a) the amount of plant-food sold with the beans and (b) the amount of plant-food contained in the pods and whether or not they are worth looking after. One thousand pounds of castor beans contain 35 lbs. nitro- gen, 4 lbs. potash and 14 lbs. phosphoric acid. The pods gathered with this amount of beans weigh ap- proximately eight hundred pounds and contain 13 lbs. nitrogen, 4h lbs. potash and lbs. phosphoric acid. The beans themselves are not exceptionally “hard’' on 10 the soil, and a comparison of the money value of castor beans with that of an equal weig’ht of other crops leads to the con- clusion that it is desirable to g'row them in preference to crops that require a large amount of expensive machinery to handle. The pods contain an amount of plant-food of more value than that present in an equal weight of average wood ashes. The value of ashes as a fertilizer is well known and utilized by careful farmers. The pods of castor beans are fully as valuable and should be taken care of and returned to the soil. Their value as a manure, based upon what the plant-food in them would cost if purchased in the form of fertilizers, is over ten dollars per ton. This figure represents the extent to which the stored-up capital of the farm is drawn upon and wasted when this portion of the crop is not returned to the soil The plant- food in the hulls is slowly available and their effect would be lasting. From their composition, they are well suited for the manuring of fruit trees and similar valuable crops. The pods cannot be sold for money, but they are a feature of this crop second only in importance to the beans, and should be put to good use and not be wasted. ALFALFA AND COW-PEAS. The preceding comprise the principal crops that are grown for market. In this connection, the class of plants to which alfalfa and cow-peas belong should be mentioned. These two are the most promising leguminous plants for forage in this climate. The}" differ from the crops previously mentioned in that they possess the power of securing from the air a portion of the nitrogen which their growth requires. Thus, when grown and fed on the farm, they increase rather than diminish the stock of fertility in the soil. When cow-peas are plowed under, not only is the mechanical condition of the soil improved, but there is an increase in the store of plant-food available for subsequent crops. The same is true of alfalfa, whether it is pastured or cut for hay and fed on the farm, the manure being returned to the soil. A Study of the Castor Oil Plant, 1897. This study consists of a determination of the amounts of nitrog’en, potash and phosphoric acid removed from the soil by (a) the entire crop, (b) the stalks and roots, (c) the leaves, (d) the beans and (e) the pods. Seed of the common variety from two sources, one Okla- homa and the other Kansas grown, and of an ornamental vari- ety, were planted May 4. During the next two weeks there was a rainfall of approximately ten inches, which hindered germination and, to some extent, prevented the plants from getting a good start. After the plants were a few inches high. 'Fable i. VARIKTY AXD PLANT No. Total Weights . j Stalk> i and Roots j Leave.s j j Beans | Pods Beans and Polls No. 1 — A . 10.52 890 ‘ :«4 828 047 B 22.^5 1127 498 808 207 080 c . ... 169-^ 1 840 481 224 197 421 u 1 01.5 220 818 229 547 E •202n 10.55 438 ! 812 225 587 Total 9449 4089 1978 ! 1541 j 1241 2782 AveiMSie 1 S9() 988 890 808 1 248 550 No. •.* -A 1882 .581 887 818 0.50 B 1870 000 880 24.5 195 440 c :>160 ! 1108 880 801 801 002 D 1077 ! 170 227 208 172 880 J‘] l.'iOO 780 80.5 2'"0 222 508 Total . .. 1 8719 ! 4850 1728 1487 1 208 2040 Average . .. 1744 871 845 287 241 528 No. H-A 184.0 1020 294 805 220 .525 B 1121 058 178 100 115 285 c 1794 940 818 802 228 580 D 2511 1889 840 458 818 770 Total 7271 4019 1180 1225 891 2110 Average , 1818 1(X)5 284 800 223 529 ll» — all except tive of each variet}^ were removed. The plants were numbered as follows: No. — A, B, C, D & E. Common variety, Oklahoma g'rown. No. 2 — A, B, C, D & E. Common variety, Kansas g'rown. No. 3 — A, B, C, D & E. Large ornamental variety. The dead leaves and ripe pods were removed daily and kept in separate sacks for each plant. d’he plants, having been killed by frost, were removed from the soil November 8. Plant No. 3E produced no beans, and was discarded. Table 1 gives the weights of each plant and of each part at the time when the samples were taken for analysis. All weights are stated in grams. Samples of the stalks and roots, the leaves, the beans and the pods were taken for each sort grown, and water, nitrogen, potash and phosphoric acid determined in each. The results of these determinations appear in Table 2. 'JabU 2. VARIETY No. AND PART Lbs IN 100 Lbs. as Sampled. Water i Nitrogen Potash Phosphor. Acid i No. 1 -Stalks and roots.. H9.89 0.24 0 34 0.06 Leaves 1 .66 1 .29 0.23 Beans 4.84 3.51 0.41 l.:38 Pods 7.14 1.84 5.76 0.20 Nt). 2— Stalks and roots fiH.99 0.27 0.45 0.05 Leaves 32 . 62 1.61 1.49 0.22 Beans 4 66 3.39 0.54 1.38 Pods 10 72 1 .42 5.74 0.15 1 No. 3 Stalks and roots 72.24 0.31 0.32 0.05 i Leaves 26.77 1 .71 1.18 0.22 Beans b . 03 3 58 0 54 1 .48 1 Pods 8.72 2 82 6.54 0.37 'I'able 3. 1 VARIETY No.. AND PART GKAMS IN Nitrogen AVage of 5 Planu's ; Potash Thosphor. j 1 Acid No. 1— Stalks and’ roots 2.25 3.19 0.54 No. 2 -Stalks and roots . . ... 2.:I6 3.V.2 0.44 , So. 1— Leaves 6.57 5.11 0.91 No. 2— Leaves 5 . 55 5.14 0.76 No. 1 — Beans 10.81 1 .26 4.25 No. 2 Beans 9.73 1 . 55 3.96 No. 1— Pods 4.56 14.28 0,,50 No. 2-Pods 3.42 13.83 0.36 — 1 :; — Prom these results have been calculated the followinj^^ tables shovvinja; the weisi’ht in g’rams of pl.'int-food removed by each part. For sake of compariso!i, the wei^^hts for the two sorts of the common variety are ^ivt-n in Table 3. Averages are shown in Table 4, as well as the total amount removed by one plant wei^^hinf.r 1^1" :^'rams. the avera<.;'e weiyht of one plant of the common variety. J'ablr 4 . \ Okams IN ONE Plant ■ PAFa’T.— AVEHA(JK (^F Nos. 1 AND ! Nitrogen Potash ;Phosphor. Acid Stalks and roots •’ :tn :t ,=>.6 0 . to Leaves « 06 .■S.12 0 S4 Beans ' 10.27 2.40 4.10 Pods .1.09 14.06 0.48 Entire plant 22.62 2.T.1.1 .=>.86 Prom these data the following' percentag'e composition has been calculated for the common variety: 'rablc j. MATERIAI. In 100 Parts Fresh Substance Nitrogen Potash iPhosphor. j Acid 1 Stalks and roots 0.26 0.40 0.06 Leaves 1 .64 1 .;io 0.28 Beans 8.4,6 0 48 1 88 Pods 1 .68 .6,7.6 0.18 I Entire plant 1.24 1 .:iH 0.82 In a similar manner the following tables have been calcu- lated from the data relating to the ornamental variety, the average weight of one plant being 1H17 grams: 'fable 6. PART. -No. 8 Grams In (One Plant Nitrogen Potash Phosphor.! 1 Acid Stalks and roots 8.12 8 :22 0..60 ‘ Leaves 4.86 8.3.6 0.62 Beans 10.9.6 1 .6.6 1,68 pods 6 29 14. .68 0.88 Entire plant . ,. •2.6. -2:2 22.80 6.48 — 14 — Prom these data the following composition has been calcu- lated for the ornamental variety: '/'able 7. MATERIAL In 100 Pak'I's Fkksh .Si mstanok Nitrogen , Potash Phosphor. Acid Stalk.s and roots O.Hl ().:« 0.0') Leaves 1 .71 1 . IH 0. Beans :5 . o.^-l 1 .4' Pods 0 . .04 o.:p Entire plant i.;io 1 -’.o o.:io I Of the common variety, 55 per cent, of the portion removed from the field, as the crop is j.^’athered in practice, consisted of beans and 45 per cent, of pods. Beans of each variety were carefully hulled and the per cent, of hulls and of beans determined with the followin^^ results: No. 1 — 75.27 per cent, hulled beans; 24.78 per cent, hulls. No. 2 — 74.75 per cent, hulled beans; 25.25 per cent, hulls. No. 3— 75. 72 per cent, hulled beans; 24.28 per cent, hulls. The most striking' feature of these results, the high manur ial value of the pods, has already been pointed out in this bul- letin. Comparison with other analyses published in Bulletin 25 of this Station reveals the uniformity of the results now reported with previous work. DETERMINATION OF OIL IN OASTOR BEANS, The large amount of oil in castor beans makes it impossible to pulverize them before extraction. In making determinations of the total oil the following method proved satisfactory. The beans were first hulled, using a knife, and the percent- age of hulls determined. The hulled beans were then sliced with a sharp knife. Five grams were weighed into an extrac- tion tube, dried to constant weight at 100° ( 7 ., weighed, and ex- tracted for sixteen hours with anhydrous ether. The oil was determined by loss in weight of extraction tube. The extracted slices were emptied from the tube, pulverized in an agate mor- tar, returned to the same tube, dried to constant weight, and again extracted for sixteen hours. A third extraction for six- teen hours showed no further loss in weight. The following table gives the weight of different extracts from five gram charges of the same sample of beans: SAMPLE 721 First Ex- traction Seco’d Ex- traction Total Oil Per Cent. Oil 1 Number 1 2.9504 0.0670 3.0174 60.35 Number 2 2,9.526 0.0632 ! 3.0158 60.32 Number 3 2.9701 0.0585 i 3.0286 60.57 Number 4 2.9542 0.0603 1 3 0145 60.29