LIBRARY, A & M COLLEGE, CAMPUS. A160-531-6000-L180 TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS {ULLETIN NO. 428 JUNE, 1931 DIVISION OF CHEMISTRY The Fertilizing Valfigé 0f Greensand v I "<4 t‘ - a I A’ =’ a *@¢I‘v@, v g ‘ <1» h 1 , , :»- n i; 4.‘;- A! AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. O. WALTON, President STATION STAFFT ADMINISTRATION: A. B. CONNER, M. S., Director R. E. KARPER, M. S., Vice-Director CLARIGE MIxsON, B. A., Secretary M. P. HOLLEMAN, JR., Chief Clerk J. K. FRANcKLOw, Assistant Chief Clerk CHEsTER HIGGs, Executive Assistant C. B. NEBLETTE, Technical Assistant CHEMISTRY: G. S. FRAPs, PH. D., Chief; State Chemist S. E. AsBURY, M. S., Chemist J. F. FUDGE, PH. D., Chemist E. C. CARLYLE, B. S., Assistant Chemist WALDO H. WALKER, Assistant Chemist VELMA GRAHAM, Assistant Chemist T. L. OGIER, B. S., Assistant Chemist ATHAN J. STERGEs, B. S., Assistant Chemist JEANNE M. FuEGAs, Assistant Chemist RAY TREIGHLER, M. S., Assistant Chemist RALPH L. ScHwARTt, B. S., Assistant Chemist C. M. POUNDERs, B. S., Assistant Chemist HORTICULTURE: S. H. YARNELL, Sc. D., Chief L. R. HAWTHORN, M. S., Horticulturist RANGE ANIMAL HUSBANDRY: J. M. JoNEs, A. M., Chi B. L. WARWIGK, Ph.D., Breeding Investigations STANLEY P. DAvIs, Wool Grader ENTOMOLOGY: F. L. THOMAS, Ph. D., Chief; State Entomologist . J. REINHARD, B. S., Entomologist . K. FLETcHER, Ph. D., Entomologist . L. OWEN, JR., M. S., Entomologist . 1&1 RONEY, M. S., Entomologist . E . F E GAINEs, JR., M. S., Entomologist . JoNEs, M. S., Entomologist . BIBBY, B. S., Entomologist GIL E. HEARD, B. S., Chief Inspector TO MAGKENsEN, B. S., Foulbrood Inspector . B. WHITNEY, Foulbrood Inspector RON OMY: . B. BEYNOLDs, Ph. D., Chief . E. KARPER, M. S., Agronomist C. MANGELsDORF, Sc. D., Agronomist . T. KILLOUGH, M. S., Agronomist . E. REA, B. S., Agronomist , Agronomist . C. LANGLEY, B. S., Assistant in Soils BLICATIONS: _ A . D. JAcKsON, Chief > Qgggqmuuém EUTDJW P >Qw VETERINARY SCIENCE: *M. FRANcIs, D. V. M., Chie] H. ScHMIDT, D. V. M., Veterinarian F. P. MATHEws, D. V. M., M. S., Veterinarii W. T. HARDY, D. V. M., Veterinarian F. E. CARROLL, D. V. M., Veterinarian PLANT PATHOLOGY AND PHYSIOLOGY: J. J. TAuBENHAus. Ph. D., Chie W. N. EzEKIEL, Ph. D., Plant Pathologist W. J. BAcH, M. S., Plant Pathologist ————~————, Plant Pathologist FARM AND RANCH ECONOMICS: L. P. GABBARD, M. S., Chief W. E. PAULsON, Ph. D., Marketing C. A. BONNEN, M. S., Farm Management **W. B. NIsBET, B. S., Ranch Management **A. C. MAGEE. M. S., Farm Management RURAL HOME RESEARCH: JEssIE WHITAGRE, Ph. D., Chief _ MARY ANNA GRIMEs, M. S., Textiles ELIZABETH D. TERRILL, M. A., Nutrition SOIL SURVEY: **W. T. CARTER, B. S., Chief E. H. TEMPLIN, B. S., Soil Surveyor A. H. BEAN, B. S., Soil Surveyor R. M. MARsHALL, B. S., Soil Surveyor BOTANY: V. L. CORY, M. S., Act. Chief SIMON E. WOLFF, M. S., Botanist SWINE HUSBANDRY: FRED HALE, M. S., Chief DAIRY HUSBANDRY: O. C. COPELAND, M. S., Dairy Husbandman POULTRY HUSBANDRY: _ R. M. SHERwooD, M. S., Chief AGRICULTURAL ENGINEERING: H. . SMITH, M. S., Chief MAIN STATION FARM: G. T. McNEss, Superintendent APICULTURE (San Antonio): H. B. PARKs, B. S., hi A. H. ALEX, B. S., Queen Breeder FEED CONTROL SERVICE: D. FULLER, M. S., Chief S. D. PEARcE, Secretary J. H. ROGERS, Feed Inspector K. L. KIRKLAND, B. S., Feed Inspector SIDNEY D. REYNOLDs, JR., Feed Inspector P. A. MOORE, Feed Inspector E. J. WILs0N, B. S., Feed Inspector H. G. WIcKEs, B. S., Feed Inspector SUBSTATIONS No. l, Beeville, Bee County_: R. A. HALL, B. S., Superintendent No. 2, Troup, Smith County: _ P. R. J0HNs0N, M. S., Superintendent No. 3, Angleton, Brazoria County: R. H. STANsEL, M. S., Superintendent No. 4, Beaumont, Jefferson County: R. H. WYGHE, B. S., Superintendent No. 5, Temple, Bell County: HENRY DUNLAvY, M. S., Superintendent -——————————, Plant Pathologist H. E. REA, B. S., Agronomist; Cotton Root Rot Investigations SIMON E. WOLFF, M. S., Botanist; Cotton Root Rot Investigations No. 6, Denton, Denton County: P. B. DUNKLE, B. S., Superintendent No. 7, Spur, Dickens County: _ R. E. DIcKs0N, B. S., Superintendent , Agronomist No. 8, Lubbock, Lubbock County: D. L. JoNEs, Superintendent FRANK GAINEs, Irrigationist and Forest Nurseryman No. 9, Balmorhea, Reeves County: J. J. BAYLEs, B. S., Superintendent No. l0, College Station, Brazos County: B. M. SHERWOOD, M. S., In charge L. J. McCALL, Farm Superintendent No. l1, Nacogdoches, Nacogdoches County: H. F. MORRIs, M. S., Superintendent **No. l2, Chillicothe, Henderson County: J. R. QUINBY, B. S., Superintendent _ **J. C. STEPHENS, M. A., Assistant Agronomist No. l4, Sonora, Sutton-Edwards Counties: . H. DAMERON, B. S., Superintendent , Veterinarian W. T. HARDY, D. V. M., Veterinarian **O. G. BABcocK, B. S., Entomologist O. L. CARPENTER, Shepherd No. 15, Weslaco, Hidalgo County: W. H. FRIEND, B. S., Superintendent _ SHERMAN W. CLARK, B. S., Entomologist W. J. BAcH, M. S., Plant Pathologist N0. l6, Iowa Park, Wichita County: N C. . MCDOWELL, B. S., Superintendent o. l7, No. 18, , Superintendent No. 19, Winterhaven, Dimmit County: E. MORTENsEN, B. S., Superintendent N L. B. HAWTHORN, 1W. S., Horticulturist A o. 20, , Superintendent , Superintendent Teachers in the School of Agriculture Carrying Cooperative Projects on the Station: G. W. ADRIANcE, Ph. D., Horticulture S. W. BILsING, Ph. D., Entomology V. P. LEE, Ph. D., lllarketing and Finance D. ScOATEs, A. E., Agricultural Engineering A. K. MAGKEY, M. S., Animal Husbandry *Dean School _of Veterinary Medicine. **In cooperation with U. S. J. S. MOGFORD, M. S., Agronomy F. R. BRIsoN, B. S., Horticulture W. B. HORLACHER, Ph. D., Genetics J. H. KNOX, 1V1. S., A-nimal Husbandry TAs of May 1, 1931. Department of Agriculture. Greensand, a mineral containing phosphoric acid and potash, is extensively distributed through Texas. Some deposits con- taining 3 to 6 per cent of total phosphoric acid and 3 to 6 per cent of total potash have been found in Bexar and other counties, but the greensand in East Texas contains much smaller percentages of phosphoric acid and potash. The potash in greensand is not soluble in water, as is the case with commercial fertilizers, but is almost completely soluble in strong acids, The phosphoric acid is not highly available, like that in commercial fertilizers, but is soluble in acids. Pot experiments on three soils were made for the purpose of ascertaining the availability to plants of the phosphoric acid and potash of greensand. The maximum availability of the phosphoric acid in greensand was 40 per cent of that of superphosphate, while the minimum was zero. The maximum availability of the potash of greensand compared with that of potash salts was 12 per cent. A liberal average availability was 10 per cent for phosphoric acid and 8 per cent for potash. The value of greensand containing 5 per cent each of phos- phoric acid and potash, compared with a commercial fertilizer of the same composition which would have a valuation of $12.00 a ton at the present time, would be $3.12 a ton if the maximum availability of the potash and phosphoric acid in greensand is used. If the availability of 10 per cent for phosphoric acid and 8 per cent for potash is used, the com- parative value of greensand containing 5 per cent each of phosphoric acid and potash, would be $1.08 a ton. Greensand has fertilizing value and could be used in quanti- ties of 5 to 40 tons an acre where it can be mined and applied at a cost closely related to its value. It does not contain suflicient fertilizer value to justify attempting to market it. CONTENTS PAGE Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 Composition of greensand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Value to plants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Pot experiments with greensand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8 Discussion of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10 Sufnmary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 . , pnmoniugmas- BULLETIN NO. 428 JUNE, 1931 THE FERTILIZING VALUE OF GREENSAND G. S. FRAPS Greensand is a green mineral having some fertilizing value, found in various parts of Texas, especially in the eastern part of the State and in the vicinity of San Antonio, and also in some eastern States of the United States, such as New Jersey, Maryland, and Virginia. The greensand in the eastern part of Texas is mixed with other materials to a considerable extent and is generally low in plant food but the deposits near San Antonio contain 3 to 5 per cent of total phosphoric acid and potash. Greensand in the early part of the nineteenth century was extensively applied to soils in the eastern part of the United States, at the rate of 5 to 4.0 tons to the acre, 0r even as much as 200 tons, with good results. About 1850, when commercial fertilizers began to come into use, the use of greensand gradually decreased. The fertilizers furnished the plant food at less expense. Very little greensand is applied to soils at the present time. An extensive bibliography of greensand is given by Shreve (12). The greensands in eastern Texas usually contain very low amounts of phosphoric acid and potash, and they have never been applied to soils to any appreciable extent. The greensand near San Antonio contains appreciable percentages of plant food and attempts have been made to market it as a fertilizer. The analyses and pot experiments reported in this Bulletin have been made in order to secure information regarding the composition of Texas greensand and the availability of its plant food to plants. Deposits of greensand are not pure but contain larger or smaller amounts of greensand mixed with earth and sometimes with shells. Greensand is composed of dark, olive green to yellowish green grains, which are essentially grains of hydrous silicate of iron and potassium (glauconite) mixed with more or less silica. In some deposits, the iron has been oxidized to brown oxide of iron, but the deposit is usually of a greenish color. Owllrrelwe in TQXBS- There are extensive beds of greensand in the Cambrian formation in the Central Mineral Regions of Texas, and in the Upper Cretaceous, as well as in the upper part of the Taylor marl and in the Navarro beds (11). Greensand beds are frequent in the marine deposits of the Wilcox formation of the Eocene. Some of the counties in which these deposits are found will be named in connection with the discussion of their composition. 6 BULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION COMPOSITION OF GREENSAND The New Jersey greensand contains .2 to 3 per cent of phosphoric acid and 1 to 6 per cent of potash, the better qualities containing 1 to 3 per cent of phosphoric acid and 5 to 6 per cent of potash. Analyses of samples from the eastern United States are given by True and Geise (15), Blair (2), and others. A compilation of 42 Texas analyses of green- sand deposits made before 1917 is given by Dr. E. P. Schoch of the University of Texas (11). Other analyses of Texas samples are given in Table 1. Samples containing more than 3 per cent of phosphoric acid have been reported in Texas from Anderson county, Bexar county, and Rusk county. All of the other samples contain less than 1.9 per cent of phosphoric acid ; samples from Anderson, Cass, Cherokee, Hous- ton, Hunt, Kendall, Lee, Leon, Marion, Nacogdoches, Panola, Rusk, and San Augustine counties contained less than 0.5 per cent of phosphoric acid. Samples containing over 3 per cent of total potash were secured from Bexar, Cherokee, Kendall, Llano, Nacogdoches, and Rusk counties, but most of the samples contain less than 2 per cent of total potash. Samp-les from Anderson, Cass, Cherokee, Houston, Lee, Leon, Marion, Nacogdoches, Rusk, and San Augustine contained less than one per cent of potash. The total potash given in Table 1 was estimated by the Lawrence Smith method of fusion With lime. The acid-soluble potash is that soluble in hydrochloric acid of 1.115 sp. gr., heated 10 hours in a boiling water bath. It is noted that practically all the potash is soluble in the strong hydrochloric acid. The potash soluble in water was esti- mated in a few of the samples and was found to be practically none at all, varying from .03 to 0.16 per cent. The iron and alumina, lime, and magnesia given in Table 1 were soluble in the same strong hydrochloric acid used for acid-soluble potash, and the insoluble was the inorganic material not dissolved by this solvent. The samples examined contained 7.26 to 30.93 per cent of acid- soluble iron oxide and alumina, 0.9 to 12.42 per cent of acid-soluble lime, and 0.18 to 7.36 per cent of acid-soluble magnesia. Insoluble phosphoric acid, by the ammonium citrate method, in 6 of the samples was found to be nearly equal to the total phosphoric acid, so that the available phosphoric acid was practically negligible, varying from 0 to 0.43 per cent, with an average of 0.23 per cent. Acid-soluble man- ganese, in 4 samples, varied from .009 to .020 per cent, with an average of .015 per cent. These analyses show that when the phosphoric acid. and potash are present in sufficient quantities to be of interest, the lime or manganese content is not large enough to justify the use of the material for the purpose of furnishing lime or manganese to soils which need one or the other. THE FERTILIZING VALUE OF GREENSAND miocmm FM m; 22K 22$. fie 8.: wfifi 5Q . . . . . . . . . .. ooh mmw mndm mnaww . . . . . . . . . .. omé NTQ no.8 omdm 3Q $3 BNBN flaw mo. wme 5w. .215 2.2“ . . . . . . . . . .. mme éww . . . . . ..e.wn...m . . . . éHsw . . . . a.» . . . . . . é.» . . . . .. . . . . . . . . . .. o5 . . . . . . . . . .. a. ww. mwém wwdm . . . . . . . . . .. mm. mm. $1: 3% mo. gm 3w Fr: mmgvw i. mm; wufim E16" modw .. . . . . . . . .. mmfl mo. 09mm NwQm . . . . . . . . . .. mv. 21m swan magi . . . . . . . . . . . . . . . . . . . . .. ‘ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. mm. 33x0 You smwwon Eon Q53 @5521“ E 255cm E 223cm 1cm :9; Eniowfi L335 nflfiom 522.5 2:8. 0C v-i tflkfiffififl 3am uiosawozn 13oF HHHHHHHMHHHHHHHHHHHHMMWM flaw Hmmmmxxxuwnummmwm wmmww . . . . . . . . . . . . . . . . . 1535M ONMQM . . . . . . . . . ..........._wxom~ oNNaN . . . . . . . . . . . . . . . . . ibwxom swam . . . . . . . . . . . . . . . . . IExoQ wvgw mmxmfmwuwwpzwmwww mfiww . . . . . . . . . . . . . . . . . . Icood fihmm: . . . . . . . . . . . . . . . . . . Icooq wwmofi ......I...........=awc@v~ $15 1.1m . . . . . 1:35»! owfi: .1 w .H ............... 51.5w 2:2 . .. . . vii 2B2 . . . . . . . . . . . . . . . . . . Jami hwwm . . . . . . . . . . . . . . . 50963-4 wmmw >JcsoU apoecnz hoflfionmd écmwcwam “o cofiioaEoo umficuuhwmll; Esau. 8 BULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION VALUE TO PLANTS The potash in greensand is chiefly combined with silica and is entirely insoluble in water. Greensand does not contain appreciable amounts of water-soluble potash such as is present in fertilizers. The phosphoric acid also is present as insoluble compounds. There is prac- tically no available phosphoric acid such as is found in commercial fertilizers. The presence of 3 to 6 per cent of total phosphoric acid and 2 to 5 per cent of total potash in some samples of greensands naturally gives rise to the question of their value for fertilizing purposes, and the possibility of their utilization. The greensand in New Jersey was usually applied at the rate of 10 to 40 tons an acre, b-ut sometimes as little as 5 tons or as much as 200 tons was used. In these amounts, it had a favorable action on the soil, no doubt supplying some phosphoric acid and potash (1, 2, 1.5). Some varieties of greensand are acid and were found to be injurious unless the soil was limed or contained lime naturally (6, 15). The chemical analysis shows the quantity of phosphoric acid and potash present in greensand butit does not show to what extent these fertilizing materials may be utilized by plants. This information re- garding new materials can be ascertained by means of experiments on plants. Very few tests have been made of the capacity of plants to take total potash from greensand, and none have been found for the phos- phoric acid. True and Geise (15) performed some pot experiments on wheat and clover with greensand from Virginia. and New Jersey, applied at rates of 1 to 30 tons per acre, using the Weight of the air-dried tops of the plants to measure the effect of the additions. The growth was not quite as good as with soluble potash salts, but the greensand sup-plied some potash. Skeen (13) compared greensand with nitrate of potash on wheat in pot experiments. The wheat grown on sand with the addition of 0.78 per cent of greensand (1.044 gms. K) secured 0.0125 grams of potassium from the greensand or about 1.1 per cent of the amount added. The wheat took up .0146 grams of potassium from 0.1103 grams of potassium applied as nitrate of potash or 13.2 per cent of the amount added. The maximum percentage of potash removed by the wheat from the greensand was 2.15 per cent of the quantity of potash ' added, which was removed from the pot containing 1 per cent of green- sand or 1.392 grams of potassium (K). If the maximum percentage of potassium removed from the greensand (2.15 per cent) is divided by the percentage of potassium removed from the nitrate of potash (13.2 per cent), the availability of the potash in the greensand is found to be 16 per cent of that in the nitrate of potash. POT EXPERIMENTS WITH GREENSAND Pot experiments with plants are used to compare the relative amounts of plant food furnished by different materials. It is important that THE FERTILIZING VALUE OF GREENSAND 9 the soil used in the pots be deficient in the element being studied, that deficiency in any other element be corrected by appropriate additions, and that the quantity of plant food added in the material being studied be less than the ability of the plant grown to take it up. It is also important to compare the amount of the plant food taken up by the plants as found by analysis and not the dry Weights of the plants, for the reason that the weight of dry matter is not necessarily in proportion to the Weight of nutrient ab-sorbed. This is particularly true with potash (see Table 4), to a less extent with nitrogen, and still less with phos- phoric acid, but even with phosphoric acid there may be decided varia- tions in the phosphoric acid contained in the crop. Unless the plant food removed is considered, the conclusion from the experiment may be erroneous. The quantity taken from any material is ascertained by deducting the amount in the crop grown Without the addition from the amount in the crop grown with it. Experiments were conducted to test the availability to plants of potash and of phosphoric acid in greensand as compared with that in commercial fertilizers. Galvanized iron pots containing 5000 grams of soil were used. Each pot received additions of fertilizer containing the two forms of plant food not being studied. When the availability of the potash was being tested, each pot received additions of 1.0 gram of ammonium nitrate and 1.0 gram of dicalcium phosphate. When the availabity of phosphoric acid was being studied, the pots received addi- tions of ammonium nitrate and sulphate of potash. The quartz sand 31116 received in addition 2.0 grams of sulphate of lime, 1.5 grams of magnesium sulphate, and 0.13 gm. of ferric chloride. Water was added to half the saturation capacity of the soil. Crops were planted as shown in the tables. The loss of water was replaced three times weekly. At the end of the period, the crop was cut near the roots, dried, Weighed, and analyzed. In some cases a second crop was grown. The samples used were ground samples of greensand from different deposits in Bexar county, and analyses of them are given in Table 1. Two portions of sample No. 29321 were used, one portion being ground ordinarily fine, the other very fine. Details of the pot experiments are given in Tables 4 to 11, inclusive. Series 99. Builders sand sample No. 29208 was used. It was reddish in color and contained some carbonate of lime. Dicalcium phosphate and ammonium nitrate were added to all the pots. Kafir was grown after the corn with no further addition of potash materials, to get the effect of a second crop. The results are recorded in Tables 4, 5, 8, and 9. Series 104. Washed silica sand from the Ottawa Silica Company, sample No. 31116, was used with additions of calcium sulphate, mag- nesium sulphate, ferric chloride, dicalcium phosphate, and ammonium phosphate. Corn was grown. The results are recorded in Tables 6 and 10. Series 108. Tabor fine sandy loam (surface soil) from Brazos county, 10 BULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION was used with additions of dicalcium phosphate and ammonium nitrate. Corn was grown. The results are recorded in Tables '7 and 11. DISCUSSION OF RESULTS Ph0SPh0ri¢ acid- A summary of the results for phosphoric acid is given in Table 2. In soil No. 31170, the availability of the phosphoric acid of greensand compared with that of superphosphate varied from 14 to 40 per cent; in soil No. 29208, it varied from 0 to 34 per cent, in the first crop, and 0 to 19 per cent, for two crops, and in sand 31116 it was from 1 to 15 per cent. The phosphoric acid in sample No. 29220 had the highest availability. Taking all the results into consideration, an average availability of 10 per cent of that of superphosphate would be a liberal estimate for the availability of the phosphoric acid in greensand. ' Table 2.—Comparative availability of phosphoric acid of greensand. Per cent Availability Soil recovered of compared with Number added phosphoric super-phosphate acid as 1 31170 (corn) Superphosphate . . . . . . . . . . . . . . . . . . . . 21 .7 100 Greensand 29210 . . . . . . . . . . . . . . . . . . . 8.7 40.0 Greensand 29220 . . . . . . . . . . . . . . . . . . . 8.3 38.0 Greensand 29320 . . . . . . . . . . . . . . . . . . . 3 .0 14.0 31116 Superphosphate . . . . . . . . . . . . . . . . . . . . 15.4 100.0 Greensand . . . . . . . . . . . . . . . . . . . . . . . . 1 .2 8.0 Greensand 29220 . . . . . . . . . . . . . . . . . . . 1.6 10.0 Greensand 29320 . . . . . . . . . . . . . . . . . . . 0. 7 5.0 Greensand 29321 . . . . . . . . . . . . . . . . . . . 1 .6 10.0 Greensand 29409 . . . . . . . . . . . . . . . . . . . 2 .3 15.0 Greensand 29410 . . . . . . . . . . . . . . . . . . . 0.1 1.0 29208 (corn) , Superphosphate 33246 . . . . . . . . . . . . . . 13.9 100.0 Greensand 29210 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29220 . . . . . . . . . . . . . . . . . . . 4.7 34.0 Greensand 29320 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29321 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29321 . . . . . . . . . . . . _ . . . . . . .0 .0 Greensand 29210 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29409 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29410 . . . . . . . . . . . . . . . . . . . .0 .0 29208 (corn and kafir, 2 crops) Superphosphate . . . . . . . . . . . . . . . . . . . . 30.3 100.0 Greensand 29210. . .0 .0 ‘Greensand 29220. . 5.8 19 . 0 Greensand 29320. . .0 .0 Greensand 29321 . . 1 .2 4.0 Greensand 29321 . . .0 .0 Greensand 29409 . . . . . . . . . . . . . . . . . . . 0.6 .2 Greensand 29410 . . . . . . . . . . . . . . . . . . . .0 .0 Variations in the recovery of phosphoric acid from rock phosphate, similar to those named above, have already been observed (3). In 21 experiments, the phosphoric acid of rock phosphate averaged 21 per cent of the availability of that of superphosphate, though it varied from 0 to 45 per cent. Potash- A summary of the results with potash is given in Table 3. The amount of potash removed from the greensand, compared with that (THE FERTILIZING VALUE OF GREENSAND 11 from muriate of potash as 100, is 4.5 to 9.5 with soil No. 31170, 0 to 9.5 with the first crop on soil No. 29208, 0 to 12.4 for the two crops on soil i No. 29208, and. 0.4 to 1.1 on soil No. 31116. Taking all the results into consideration, an availability of 8 per cent of that of muriate of potash would be a libe-ral estimate for the availability of potash in greensand. The potash taken up varies to a less extent than the phos- phoric acid. Table 3.——Comparative availability of potash of greensand. Per cent Relative avail- recovered ability (potash Soil Number of potash added in muriate or as sulphate 100) 31170 (corn) Muriate of potash . . . . . . . . . . . . . . . . . . 79.8 100 Greensand 29210 . . . . . . . . . . . . . . . . . . . 7 . 6 9.5 Greensand 29220 . . . . . . . . . . . . . . . . . . . 3 .6 4.5 31116 (corn) Muriate of potash (0.5 gm.) . . . . . . . . . 75.6 100 Muriate of potash (1.0 gm.) . . . . . . . .. 68.9 . . . . . . . . . . . . . . .. Greensand 29210 . . . . . . . . . . . . . . . . . . . 0.8 1.1 Greensand 29220 . . . . . . . . . . . . . . . . . . . 0.4 .5 Greensand 29320 . . . . . . . . . . . . . . . . . . . 0.4 .5 Greensand 29321 . . . . . . . . . . . . . . . . . . . 0.3 .4 Greensand 29409 . . . . . . . . . . . . . . . . . . . 0.4 .5 Greensand 29410 . . . . . . . . . . . . . . . . . . . 0 . 6 .8 29208 (corn) Muriate of potash . . . . . . . . . . . . . . . . . . 77.9 100 Greensand 29210 . . . . . . . . . . . . . . . . . . . 6.4 8.2 Greensand 29220 . . . . . . . . . . . . . . . . . . . 7.3 9.5 Greensand 29320 . . . . . . . . . . . . . . . . . . . 4.6 5.9 Greensand 29321 . . . . . . . . . . . . . . . . . . . 6. 1 7.8 Greensand 29321 (50 gm.) . . . . . . . . . . . 1 .5 1.9 Greensand 2921 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29331 . . . . . . . . . . . . . . . . . . . 4.0 .51 Greensand 29409 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29410 . . . . . . . . . . . . . . . . . . . 0.8 1 .0 29208 (2 crops, corn and kafir) Muriate of potash . . . . . . . . . . . . . . . . . . 91 .9 100 Greensand 29210 . . . . . . . . . . . . . . . . . . . 10.8 11.8 Greensand 29220 . . . . . . . . . . . . . . . . . . . 11 .4 12.4 Greensand 29320 . . . . . . . . . . . . . . . . . . . 4. 6 5 .0 Greensand 29321 . . . . . . . . . . . . . . . . . . . 6.1 6.6 Greensand 29321 (50 gm.) . . . . . . . . . . . 1 .5 1 .6 Greensand 29210 . . . . . . . . . . . . . . . . . . . 0. .0 Greensand 29331 . . . . . . . . . . . . . . . . . . . 4.0 4.4 Greensand 29409 . . . . . . . . . . . . . . . . . . . .0 .0 Greensand 29410 . . . . . . . . . . . . . . . . . . . 0 . 8 0.9 The potash removed may be compared with that removed from other minerals. Fraps (4) by means of pot experiments found that, with the potash removed from sulphate of potash as 100, the comparative percentage removed from finely ground microcline and orthoclase Was 2 to 10 per cent, from muscovite 25 to 30 per cent, from biotite about 35‘ per cent, and from nephelite about 20 per cent. The potash in green- sand is not taken up as readily as that in biotite or muscovite, Which are varieties of mica. High quantities 0f gfeellsalld- The effect of larger amounts of green- sand was tried in several experiments. On soil No. 29208 (Table 4) increasing the greensand 5. times increased the potash taken out only about one-sixth, and the amount removed was much lower than from 12 BAULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION less than one-fourth as much potash in muriate of potash. The second crop (Table 5) recovered practically’ no potash from this large addition. Only small amounts of phosphoric acid were removed from 50 grams of greensand alone (Tables 8 and 9), or supplemented by nitrogen, although the nitrogen increased the amount of phosphoric acid taken up. Value 0f greensfllld- A fertilizer containing 5 per cent each of avail- able phosphoric acid and water-soluble potash, at the prevailing valua- tions (5) of 6 cents a pound for each, would have a fertilizer valuation of $12.00 a ton. With the maximum availability found in these experi- ments of 40 per cent for phosphoric acid and 12 per cent for potash, the value of a greensand containing 5 per cent of total phosphoric acid and 5 per cent of total potash, compared with the commercial fertilizer, would be $3.12 a ton. If instead of the maximum availability for greensand, there is used the liberal estimate of 10 per cent availability of phos- phoric acid and 8 per cent availability for potash, the comparative value of the greensand mentioned above would be $1.08 a ton. Greensand containing less phosphoric acid and potash would of course have a lower value. The use of greensand at the rate of 10 to 40 tons per acre would no doubt supply some phosphoric acid and potash to the soil and so in- crease the growth of crops on soils which need phosphoric acid and potash. Greensand could be utilized when it could be mined and ap- plied at a low cost. The fertilizing value is too low for commercial sale in comparison with ordinary commercial fertilizers. other HSBS- Attempts have been made to use greensand for the manu- facture of potash salts, and it is also used as a “Tater softener (12). ACKNOWLEDGMENT Analyses and other work in connection with the preparation of this Bulletin were done by S. E. Asbury, E. C. Carlyle, T. L. Ogier, W. H. Walker, and other members of the staff. 13 THE FERTILIZING VALUE OF GREENSAND m.o 2m mm .59 <9 > 339k _m¢Q. _m_¢. 3mm. 2mm. 2mm. 5mm. 2mm. mmmm. m_HJ7<\# a2» E cwmmon GOHZUUN 530M I/ @@. . . . - ..-..... . . . . . . . .... -...-...-.........-..._ .-Q.-QUQHQ>< 8.2 m.» . . . @622 mm mm. m. S . 202m mm mw- N. . . . - - . . . - . . . . . - ~ . . ‘Em #31. ...... - . . . . . . ... . - . . . . . . . ... . -- . - mm. v2 202a mm mm. mm mte. . . . . . . . . . . . . . . . . mmmmm Eam=mEm ém o2 2020 mm . - . . . . . . - . - - . . . . . . . _ . . . ‘ . . . . . 1 - 1 - - - - ~ 0 p . - a 1 - - . u ¢ ¢ v . v - - mm. m2 x020 mm mm; mm muzm $ 2: mm. 12>. . . . . .€==2m 22.5 22mm E§.=...Sm Em 2 202m 3 . . . . . . . . . . - . . . . . . . - . . . . . ..... - . . . . . . . . ..~...... .....@w@>~U>< S; mm 52m mm mm. m2 522a 3 mm. v2 mmmm . . . . . . . . . . . . . . . . . 5.3m uiisfim ém m 2 522a mm im. . . - . . . - - . . . . . . . . . v . . . . . . . . . . . . . . . . . - - . . . - t - . . . . . . . . . . » . - mm. >2 62c mm mo; 9: 52m? S. :2 1:2 . . . . . . . . . . . . . . . . .522 miwémfim Em c2 52c 3 . . . . . - . . . . . Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mm. h. I 52o mm “m. .72 52o mm mm. #2 Em. . . . . . . . . . . . . . . . . mmmmm _.=2.:Em Em m 2 52m S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mm. m2 52c mm .2... m2 52m mm S; m2 2%. . . . . . . . . . . . . . . . . mmmmm miwzsmmm Em m2 52a S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . - . . 3. m2 520 mm mm. m. I 52o mm mm; <2 3.1 . . . . . . . . . . . . . . . . 23m “Emmfimhm Em m2 52o 5 . . . . . . . . . . . . . . . . . . . . . . . . . . ... - . . . . - . . . ... .. . . . . . .. ..- 8m 92 322a mm mmm m2 322a mm i; m2 82.. . . . . . . . . . . . . mmmmm mmfiom E .3258 .Em 2 $22G mm 25o 5Q mEwLm c0332“ .154) :4 .131, m: S2332 14 BULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION Bw. .. . . . . . . . . ... . v . . . . . . . ... . . . . . . . . . . ..®@N.~O>/_< R9. mm; flu 2U E 28. 2.; fin :0 o... 38. hm. fi ow mmma . . . . . . . . . . . . . . . . . . .58.». v=fi=xzw .Em o... 3U 2. o. fiem sx. . . . . . . . . . . . . . . . . . . . . . . V . . . . .-....... . . . . . . . . . . . . . . ..Qx@HU\/< wmfi mm. f2 EOZQ ma. £8. mm. m. I MUZD B. 28. w“. _.m 5.. 656% 22.6 32m viaavfim Acm 2 EUZO 3N O. . . . . _ . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . ... ....UMN.~Q>< 2g. E; ma. mOnZfi Q $2. E. v.3 EDS/HQ 3 Qua m»; ma mmma . . . . . . . . . . . . . . . . . . Ammmm “Ewesfiw .25 9.. QUQZQ mw Q. . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... ....0mfihQ>< $8. Q. “a. SUZQ Q. may... mm. “Q QUZQ Q . - . . . . . . . . . . . . . . . . . . . . . ‘ . . . - . . v . . . . . . . . - . . . . . . - . . . . .Ew o. D. om. . . . - . . . . - . . . . . . . . . . . . . . . . . . . . . . - . . .» ‘ - - . . - - . - . . . ... 55. E. 5: “UZQ mm mvmo. ...». wfi EUZQ w». omwo. ma; mm SQ. . . . . . . . . . . . . . . . . mmmmm fizaészm Acm 0.2 202D .8 w.” Q§. . u.» . . . . . . . . - . . . . . . . . . . ._~ . . . . - - - - - - - . . - .... ._-.@wxn%®>< E2 5. 9S . ZUZQ mm o9: Q. wfi QUZG mm Aux: “w. N3: 03% . . . . . . . . . . . . . . . . dmmmm vszqxzw 4cm 92 SUZQ w... $.§. . .. .... . . _ . . . . . . . . . . . . . ...............,...-...v ...U@@-HU>< . mo: ma. m3 $02G mm $2 N“. 9: EDZQ mm momo m“. m. I Xv. . . . . . . . . . . . . . . . . 53mm vswéwfiw Anm 0.3 EDZQ Hm . -...-.- . _ . . . ... . . . . . . . . . . . . . ...-... ... --... $2 3; Qfi mEZQ om SW2. mm. 0.2 mMZQ mm 3:. om. ma? >89 . . . . . . . . . . 5mm?“ @223 B 035E .Em c; wKZQ 2 Q30 c. Eva 5Q 232w nomzvww 10.35003 SUZO @223 £96 E doh. E swfion c0533“ 53cm “om Q3 5m .6>o "saw mEmBU nwmfiom .2230 338$. $2.5 .8“ dommm dZ =3 no humx mo no.8 vacuum .3 wzfion-lkm 03am. 15 THE FERTILIZING VALUE OF GREENSAND .....0UN.~O7¢ 30o. 3. 0.0 202a 2H £90. 3. 9o . 202m w». m . . . . . . . . . . . . . . Uifimflflwhw u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22m. aw.» 2w 312a 0m M63. 30a o2 312m mm 0E». 2; mew a2: . . . . . . . . . . .53», .122... 3 325E .5» 0A @220 3 @.Am.§ - . . . . . . - . . . . . . . v . . . . . . . . . . . . . . . . . . . . - . . .. . . . . _ . . .. ..U%NRQ>I< .22. £2 m2 822a mm R2. i. 2 m2 @220 mm 88. 8a o2 was . . . . . . . . . . s23 22:3 a. QEEE Em m5 “x20 S ........................ mwfi. .. . . . . . . . . . . . . . . . . . . . . . ..........._.............. .....Uw.NHU>< 88. 3. 2.0 ZQ 2.. . can» $04 25¢. S. 2.0 ZQ 2 :23 $04 88. 2... :0 o. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3262 20$ 2.6 E Eva Ba £52m coaibum 039/0092 ZQ 223cm douo E 50.5 E £23.00 c3323 $230k Hob 2.200 20mm 9.1/6 E20 2530 273cm E235 252.0 .2322 0o.“ 602 310m 6:5 dZ 1cm co E0... at? 35082098 we mmwfiwfilld 03mm. @. i §R.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..UmNkQ~/< m3? E 202a 90 9x8. 3 Q2 . 202a 2 .62. t. 2.2 m? . . . . . . . . . . . . . . . . . . 53.2.. 25225.02 Sm 2 202a 20 . .... . . . . .. . . . . . ... . . . . . . . . . . . . . . . . . . . ..... .. . . . . . .. ...'.Q@NHU>< @220. mw h. S 2020 8 £8. ow Nd 202a 2 fl . . . . . . . . . . . . . . . . . . . . @F~NWQ@UH@ .E@ sq fihwO. wmQ “Tm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .....®wm.~®>< $8. E2 0; .02 E £8. 3. 2 m. a .02 2 nm.@. . . . . . . . . . . . . . . . . . . . @Q.NWQUUM@ Jam 0oz 16 BULLETIN NO. 42s, TEXAS AGRICULTURAL EXPERIMENT STATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 . . . . . . . . . . . . . . .Q®W.~Q>< 58. mm. o. SUZQ S. 56.. mm. o». . . . . . . . . . . . . . . . . . . . . swzm 2 mmoo mm. o H m2. 23a wiaeowhm .Em 2 202G mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .....QWN.~Q>< Mwmw. w. 3 “HQ/a a :23 93A UZQ on m6? om. m. mom . . . . . . . . . . . . . . . . . . QEWN wiwévfim .Ew 2 IUZQ 2. no foo. mfioo. on m. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .....vmm.$>< oooo ma. ~ .0 ZUZO 3 Sac. om. w. SUZO Q oooo. 8. fio 5w. . . . . . . . . . . . . . . . . . . gmmfi ucméfizw .Em 2 EUZQ 3 52$ 3E4 Mmw. W. .......... . . . . . . . . ................................ .....Um&MU>.< mmoo. 2. no 202G mw wmoo. mo. no ZUZQ 3 oooo. mo. ~ .o §v. . . . . . . . . . . . . . . . . . . ommmm E5235 .Em 2 SUZQ Q E23 26A . . . . . . . . . . . . . . . . . . . . . ... . . . . . ... . . . . . . . .....mwwflh®>< ~39 N? c; EUZQ mv is... Q. 5o BUZQ Q omoo. Q. h. 2%. . . . . . . . . . . . . . . . . . . ommmm _.=~esfim .Em 2 BUZQ 3 no.8 E Eve 5Q wEmhw coflmoww wwkz/ouwh ZQ amnion. A35 E doh. E A230.“ comic?“ 33cm 3m £60 3m ,8>o EQU mEwEU nmwoom gamma? 252.0 . ionafiaonvlamfiom B.“ £2 woiom 6:5. dz mow so E8 as? 3.85.2258 Ho mzfun-lao Bank 1"! THE FERTILIZING VALUE OF GREENSAND ...... .... . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ....@@NH@>< $3 hmfi m4; SUZQ 3 mmam. 8. _ mam BUZQ mm iém. Nwé N42 c3. . . . . . . . . . smflfi Eam=2zw 4cm 2 BOZG wm ©.§\ . - - u . . . . - - - . - - - . - - . - . - . . . . . - » . . 1 - - - . - - - - w ~u- u l .- . Mai... mwa 52 “UZQ hm £3 S.m 55 I I . hUZfl 8 Rwm. “w. w m. 5 vfl. . . . . . . . . . . . . . . imam E§=~2m Em 2 202G mm . . . . . . . . . . . . . _ . . . . . . ..> . . . . . . .....» . . - . - . -...-.- ...-.®m.@»m@>< Chm. Ed w. § fimzo § NEm. iim saw . . . . . . . . . . .. 4 . mMZQ mm $.31 :5 i: Sim . . . . . :36.“ “c 322:: Em m. o QMZQ mm . . . . . W . " . . . . . . . . . V . . . . . . . . . . .. . v. . .-. . . . -. . . . . w’ . .. . . .. . . . . >.. . - ..-- .. 26m. 2a 3N“ ZQ ~N min. 19w wag ZQ om wmmm mofl mdfi o. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I252 Zn- 2 l} no.6 E “coo 3a wimuw c3335 _5.$>ov@.. ZS 53cm do? E .QO.~0 E nmmwoa sofizvwm 53cm “om ER. Em $50 EH20 252.0 smfiom 2mm»? mEabU .4930.» .5.“ .wOfi 32am Kvfiwmm .02 mom 2.200 mHGoEIQQxM-la. 2am? 18 BULLETIN NO. 428, TEXAS AGRICULTURAL EXPERIMENT STATION %2 o- NN. m-§ n 2 . . - . 2 2 1 - - - . » . . - ¢ . - - v 2 2 . . . - . ~ . ¢ - '2. . 2 0 . u a u .0020 n2. 0.0 2022M 2N 22220 NN. 0.0 2022M 0N 2.020 “N. N0 0NwN. . . . . . . . . . . . . . 20000 .02 222200220020 222w 0.02 2022M 02 o. @§- . - - . . . . . . . . . . . . . . . . . . - . . . 2 - . - . - - . . - 2 . . . . . . . $00. 02. 2.2.2 . .0202 02 0020. >2. 0.0 202M 22 @020 2N. 0.0 2002.20. . . . . . . . . . . . . . .2080 .02 22220022005 222m 0.N 202M 02 o. o. @%- . . . . . . . . . . . . _ . . . . . . . . . . . - - . . - - . . . . - - - - . . ~ -®x@1~mw>< 02N0. 02. 22.22 202M m2 00N0. 2N. 22.0 . 202M 222 @020 02. 0.0 02.00. . . . . . . . . . . . . . 00000 .02 20220m22002w 2.22m 0.N 202M 02 @@. -....... . . . . . . . . . . . . . . ._.....................-.. .-..Q@“hmw>< 5N0. >2. 0.222 202M N2 22hN0. NN. 22.N2 202M 22 0000. 0N. 22.22 02.00. . . . . . . . . . . . . . .0NNON .02 2022002200222 622m 0. N 202M 02 o. o. fix. . . . . . . . . . . . . . . . . . . . . . . . . . . . - - - . . . - . . . . . . ¢ . - . . 0200. 0N. 0.2.22 202M 0 02020. 2N. 0.0 202M 0 N2N0. mN. N0 02022. . . . . . ..........02NON .02 20220022003 222m 0N 202M 2. e».@% é§. .. . . .. ...... . _ . . .............................. ..U%NHU>< 002.0 2.2. 0.2~N 222M 0 0000 mN. 0.02 222M 0 0000 NN. 0.222 0.200. . . . . . . . . 022N022 .02 02022220022225.0220 222m 22.0 022M 2. . . . . . . . . . . . . . . . . . . . . . .. . .. . fvmmhw>< 02.02.. 2N. 0.22 2M0 0200. 00. 0.02 2M N 2~NN0 0N. N.22 0. . . . .. .. 2M2 1| 220.20 22022220200 20020220002 2M .20>0 222 20200 22200 0022 02220.20 222 20200 22200 .2022 22200 02202222002222 A2020 222 22200 .220.20 02202222002222 22022220220 0202222002222 02.2.2022 02220.20 02202222002222 .3303 02220.20 .00 002225. .w0N0N .02 220w .0200 02202222002222 .202 22.200 2222B 22205220220010 02220.2. 19 THE FERTILIZING VALUE OF GREENSAND :6? hmflo mm. o.n . . . . . . . . . . .. ~m_o NN. ¢.@ ww_¢ mm. m.> ¢@_o cm. @.§ ¢@~_ ¢@_¢ afi. h.w . . . . . . .. @@_¢ hw. m.- m<~¢ @_. m.> ¢¢_¢ om. Q.» <@@¢. mmflo. vm. m.m . . . . . . . . . . .. wwwo fin. m.m mw_¢. ~N. >.w mwwo. hm. w.@ @_q._ wnoo. wm. N.m ...... . . . . .. wmoo. NW. _.m wwoo. mm. m.m owoo. mm. N.m oQ_¢._ wvmo. om. m.- . . . . . . . . . . .. oomo _~. m.¢~ mwwo. @_. w.~_ _w_¢. ~N. w.w ¢¢~_. .358». mzmcc dflmmm .02 wcmmcouhw .8» 0N . . . . dmm$>< zwzmow :mvzu~@m __m:4v~wm ...@w@->< BUZZ hm. :m:4v~@m ._mv~Av* mm .....@m-@>< .mv7H¢@ .07~m@ .mv7H~m .....~m-@>< .....umm~o>4w hUZM>N mm:4v~@~ h7fiVM mm 20 BULLETIN NO. 428,“ TEXAS AGRICULTURAL EXPERIMENT STATION o. o. mmfio mfi. @.¢~ mwfio ¢_. w.- mm_o m_. w._~ . H¢_o. >~. m.w N.“ hooo. wwfio vfi. N.~_ ~@Ho. ¢_. m.__ mw_o. n_. o... @@_¢ <_. ~.¢~ c. o. ¢m_o mfi N.Q+( wm_¢ <~. >.@ mmfio m_. N.o~ m§_¢ @_. w.@_ _._ woos. @@_¢. @_. ¢.__ ._@~¢. mg. >.o_ wmfio. m_. m,@_ ¢¢_¢ om. m.> o. o. _m_¢. w_. ¢Aw vows. qm. m.w mmfio. ¢.. @.@ @__o. w_. N.» v.@_ ¢¢_o. fiomo. m<. 0.“ .16“? . . . . T . .@.. . . . . . . . $5.... . . . . . . . . . . . . . . . . . . . . . . .. fiwflo. cfl. m.o_ w@_¢ @_. m.@_ omfio ¢_. >.¢_ mwfio n_. p.@ 11 nope ||1|||!§|||| ufii/ouon ZN .$>o E Eon E3 8n 952w “so... 3m EmU oionnmonn .QO.~Q E 3cm 50.6 mEmbO oionnwoam .3335 .52.?“ a 28 oiosnmona 252$ . . . . . . . . . . . . . Rvz rviflwgmwwh@ Jhnw ..I. . . . . . . l§mmm oZ wcwwcwukm Em o m . . . . . . . . . . . . dmmmm oZ vcwwcouuw Ew o N W H 1W M H H M M A“ H .. ..mfiw. Tohlwwmwwwwfi» m K HMUMUHMMUMHH.....HV.._N»N_ .o.7.H.m.=_~.».._M..+.w. Twww . . . . . . . . évmmm dZ owmsmwonahwasw Em m o =os=iw Qfifizzm 6a mwiwm demon dZ mom .58 mEBoEG Qawx at? Qcoimhvnxmld QEQP . . . . 6mm$>< . . . . bmm$>< IUZM M: 202M 2 JvZM m: . . . ‘ Qmm$>< “OZM 5 MUZM E EDZM 2 . . . . dwm$>< 202M 2 . . . . émfiv>< .21 THE FERTILIZING VALUE OF GREENSAND aN. ......... . . . . . . . . . . ...... ................... .....Qmfl.~0>< $00M ddm m} ~02M d2 .300. Md. 5d ~02M I 2.000 0d h M 0000 oddmd .02 @E.E.....:...... .Em d ~0M2 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . ..0wflh@>< £00m 02m 0d .0M2 0 wd00. 0d. 0.2 . .0M2 w $8 0d m M $2 28m dz vaméwfiw Em d .0022 h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..0wflhw>< 020m mdm 0Q AMZ 0 X20 wd d N. QMZ m 030 0d. 0.0 300. 02000 .02 Bmiwogfima... .Ew 0.0 LMZ 2. NN. . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . ... . . . . . . . . . IOMNMU>< 0000. 0M. m0 M2 m $.00. 0H. 0d M2 d hd00. hd. 0.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M2 H Q96 c0310?» 030.53g 2M .6>o E Bow 25o .80 282w E 06m E60 Em Em0 2.6.3.920 dope E Eva .096 “Ehonamona 200E335 ogwnamosm $132 .2220 vies awash Jnmmvk/ @5220 66w oioaawona .30 J2 woium .0220 .02 mom .58 at? U-GQEMQQQKMIOM oEwH o. AKZP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . .- 030 3. 0.02 202M 00 5A0 0M. d0 202M 00 M020. .3. .1: 00d2 . . . . . . . . . . . . 103.0». d2 v5.28... .Em 0.d 302M w... c. o. x-i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . 0:0 m2. “m: 202M >0 dm~0 0M. m0 . 202M 0m. $8 .3. i. @000. . . . . . . . . . . . . . 030d .o2 “Emmsfxtm .Ew 0d 202M m... . . . . . . . . . . . . . . . . . . . . . . . . . . ,.. . . . . . . ..= . . . . . . . . . . . . . . . . . . ..Uw@hU~/4 EHO. 3. 0.0M 202M wd d0d0. 0M. 0.0M . h02M 0d 0000. 3. 0.0 0.32. ..0::o.m .22.: 0Md0d d2 05.23% .50 0.d 1202M 0d 22 BULLETIN NO; 42s, TEXAé AGRICULTURAL EXPERIMENT STATION . . . . . . . . . . . . . ‘ . . . . . . . . . . . . . . > . . . . . . . . . . . . . . . . . . . . . . . . . . Em... ma. o4; mNMZ 2.. 28. mm. §§ ANMZ mm ammo. fim. v2 wfl: £21m dZ vagemafirwfiz 4cm c; QNMZ mm %.o ON- €-? . - . . ~ . . - . . - . . . . . . . . . - . . . . . . - . » . . - - - . . . . . . . - . . . . . . . . . 3A5. 8. ma @0422 § S8. 2. fi; ZUMZ mm 22.. mm. M; 8Q Qsaw dz 325.5“ Em N fuzz mm %§. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . . . . . . ... . . 3&9 mm. fin “U22 § Ea? f. ca... EUMZ on 52.. ma. mfl +26 2.5m dZ wiésfiw .Eu m ibMZ i @.é . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . . . . . . . . » . . . . - . . . . . . . . . . . m8? 2. m... ..uzz M2 omoo. i. m; IQMZ S $8. mm. ma “ma? Ewan oZ Hzfiizzw .Em m __uxz 2 v.0 wooa. mmoo. "m. wé . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iuwu$>< £8. ma. ~A "UMZ E ~89 8. fiA EDMZ 3 mmoo. g. 9m wSQ. 8mg d2 wizfisa .Ew w “UMZ m" . .88 coming“ uuhfwouuh . ZN .$>o E Eon E3 5Q £52m E Eon E3 3m c190 oicanwosn do? E Eon dog uioznmonn comic?“ vfisawozm mViwE 2:30 23:30am Jsmfik/ @5910 .U0UQ$GOQIUMUN. OMQOJQmOSQ .3“ muivm .02 mom JQQOO QGQEtQQKMnIUQw 071w? 23 ‘J. THE. FERTILIZING VALUE.~.OF. GREENSAND< WSW “f: ovmmT. 58. mv. . .. .. . .. dwwho>< : ma? mm. 0.2 mamz 2 28. 5.. ma; QEMZ S afio. 2.. w? .53. Sfigwofimhvai Em H @324 3 04m ,.oo. wmmo. 5m. wpm .. .......owa._o>< U, , m3? mm» #2 5&2 B 1., $2.. ém. in 2OMZ 3 j mono. S. 92 ma”... 82m dZ “Ewmaxzw .Em N “OMZ .2 @.@ Amfl. ... ..~.-. .. .-...........-.J..<..-...... .....®w@HQ~/< E8. S. 92 NOMZ N“ 2.3 3.“. 92 v “UMZ I A .28. 3.. 5m; $39 83w dZ “Ewévfiw .Ew N SUEZ 2 W-x §m. . . . . . .-.-.- .- .----.-...-.....¢.-...-... .-...QwNHQ>< mmmo. mm. 0.: SUMZ m 83. mm. méfi . SUEZ w n85. wm. 9Q 3:. 22m dZ wimfixzm .Em N SUEZ N. §.\ $x. - - - - - -- 0c ¢¢-o¢v-.-u---»..~ ' - - - ¢-¢ . . £8. :2 i: mmz w m3? “m. 5S . mMZ m $2.. mm. 0.2 S8. Qfiiwoafivném 4mm m... hi2 v mm. - - 0 9n n .1 - - - ¢ - it: - I 0 - . . I - Q 1 w‘ - to - -e- v . u - ¢ - - - - Em... mm. mbfl NZ m .33. mm. 92 . NZ z wmwo mm. ma“; o .. vwZw n20 c053?“ . E uohoivuvk ZM $>o E Bum E3 :5 mEEm E Eva . Eon Em EwU oionnmonn £05 E Eon 50.8 oionnwosa noflnvcw 3933mm wviflz wEEU uicnnmonm .2303 @536 Axon ofiuonnmcnm s“ 50w moiow 6:3.“ dz zom 5.50 at? acoiionxmm|fiw 013M. Zl BULLETIN NO.9'428,'TEXAS AGRICULTURAL EXPERIMENT STATION SUMMARY Greensand is a mineral containing phosphoric acid and potash ex- tensively distributed through Texas.' Some greensand deposits contain- ing 3 to 6 per cent of phosphoric acid have been reported as occurring in Anderson, Bexar, and Rusk counties, while deposits containing 3 to 6 per cent of total potash have been found in Bexar, Cherokee, Kendall, Llano, Nacogdoches, and Rusk counties. Deposits occur in East Texas, but ighenerally contain only small percentages of phosphoric acid and potas . ' Greensand was formerly extensively applied to soils in the eastern part of the United States at the rate of 5 to 4O tons to the acre, with good results, but it is little used at the present time. The potash in greensand is not soluble in water, as is the case with commercial fertilizers, but is almost completely soluble in strong acids. The tphosphoric acid is not available, like that in commercial fertilizers, but is also soluble in acids. a - -Pot experiments on three soils were made for the purpose of ascer- taining the availability to plants of the phosphoric acid and potash of greensand. The availabity was measured by the quantities of phos- PhOfiC acid and potash removed by corn or kafir, from several samples of greensand, in excess of the quantity removed from the soils compared with: the amounts of potash removed from muriate or sulphate of potash or the phosphoric acid removed from superphosphate, under the same conditions. The maximum availability of the phosphoric acid in greensand was 40 per cent of that of superp-hosphate, while the minimum was zero. The maximum availability of the potash of greensand compared with that of potash salts was 12 per cent. A liberal average availability was 10 per cent for phosphoric acid and 8 per cent for potash in greensand. The value of greensand containing 5 per cent each of phosphoric acid and potash, compared with a commercial fertilizer of the same composi- tion which would have a valuation of $12.00 a ton at the present time, would be $3.12 a ton if the maximum availability of the potash and phosphoric acid in greensand is used. If the availability of 10 per cent for phosphoric acid and 8 per cent for potash is used, the comparative value of greensand containing 5 per cent each of phosphoric acid and potash, would be $1.08 a ton. Greensand has fertilizing value and could be used in quantities of 5 to 40 tons an acre where it can be mined and applied at a cost closely related to its value. It does not contain sufficient fertilizing value to justify attempting to sell it as a commercial fertilizer. \ c‘ nu“..- (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) <11) <12) 03> (14) (15) THE FERTILIZING VALUE OF GREENSAND. REFERENCES Blair, A. W., 1916. The agricultural value of greensand marl. N. J . Agr. Expt. Sta., Cir. 61. Blair, A. W., 1919. Glauconite: Utilizing soil potash by means of intermediate crops. Proc. Soc. Promotion Agr. Science, Jan. 6-7. ~- Fraps, G. S., 1917. The availability of phosphoric acid in rock phosphate. Texas Agr. Expt. Sta. Bull. 212. ~ Fraps, G. S., 1921. Availability of potash in some soil-forming’ minerals. Texas Agr. Expt. Sta. Bull. 284. Fraps, G. S., and Asbury, S. E., 1930. Commercial fertilizers in Texas and their use. Texas Agr. Expt. Sta. Bull. 415. ' - Kelly, J. W., 1923. Probable cause of the toxicity of the so- called poisonous greensand. J. Agr. Res. 23:223. Lipman, J . G. & Blair, A. W., 1917. Vegetative experiments on availability of P and K compounds. N. J. Exp. Sta. Rep. Dept. Soil, Chem. & Bact. 353. McCall, A. G., 1921. The effect of manure-sulfur composts upon the solubility of the potassium of greensand. J. Assoc. Ofi. Agr. Chem. 4:373. i McCall, A. G. & Smith, A. M., 1920. Effect of manure-sulfur composts on the availability of potassium in greensand. J. Agr. Res. 19:239. - Rudolfs, W., 1922. Sulfur oxidation in inoculated and uninocu- lated greensand mixtures and its relation to availability of potash. Soil Science, 14:307. ~ Schoch, E. P., 1918. Chemical analyses of Texas rocks and min-. erals and water. University of Texas Bull. 1814. - 1 Shreve, R. N., 1930. Greensand bibliography to 1930. U. S. Bureau of Mines Bull. 328. * Skeen, J. R., 1925. Greensand as a source of potassium for green plants. Am. J. Bot. 12:607. Smith, A. M., 1921. Pot culture tests on the availability of potassium from greensand composts. Jour. Assoc. Off. Agr.) Chem. 5:133. True, R. H. & Geise, F. W., 1918. greensand as a source of potash for plant culture. 15:483. Experiments on the value of‘ J . Agr. Res.