August 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
(4) Bungenberg, de Jong, H. G., Kruyt, H. R., and Lens, J., KoLZoidBeihefte, 36, 461 (1932). (5) Debye, P., and Bueche, A. M., J. Chem. Phys., 16, 573 (1948). (6) Eirich, F., private communication. (7) Eirich, F., and Riseman, J., J. Polymer Sci., 4, 417- (1949). (8) Ewart, R. H., “Advances in Colloid Science,” Vol. 11, p. 211, New York, Interscience Publishers, 1946. (9) Huggins, M. L., J . Am. Chem. Soc., 64, 2716 (1942). (10) Huggins, M. L., J . Applied Phys., 14, 246 (1943). (11) Huggins, M. L., Proc. N . Y . Acad. Sei., 44, 431 (1943). (12) Janssen, A. G., and Caldwell, B. P., Polymer BUZZ.,1, 120 (1945). (13) Kirkwood, J. G.9 and Riseman, J . (%?m. PhWs 16, 565 (1948). (14) Kraemer, E. O., “The Ultracentrifuge,” edited by T. Svedberg J.3
and K. Pedersen,
p. 57,
1191 Oxford, Oxford University Press,
1940.
(15) Martin, A. F., presented before the AMERIC.4N CHEMICAL SOCIETY, Memphis, Tenn. (April 23, 1942). (16) Signer, R., and Gross, H., Helv. Chhim. Ada, 17, 335 (1934). (17) Simha, R., ”High Polymer Physics,” edited by H. A. Robinson, p. 410, Brooklyn, N. Y., Chemical Publishing Co., 1948. (18) Spencer, R. S., and Williams, J. L., J . Colloid Sei., 2, 117 (1947). (19) Spurlin, H. M., Martin, A. E’., and Tennent, H. G., J. Polymer Sci., 1, 63 (1946). (20) Staudinger, H., and Heuer, A . , 2. PhUsih. Chem., 171, 165 (1934). RB:CEIVED January 19, 1951. Presenthd as part of the High Polymer Forum before the Division of Physical and Inorganic Chemistry, 117th Meeting of the AMERICAN CHEMICAL SOCIETY, Detroit, Mioh.
EEect of Fluorine Carriers on Crops and Drainage Waters W. H . MACINTIRE, S. H. WINTERBERG, L. B. CLEMENTS, L. S. JONES, AND BROOKS ROBINSON The University of Tennessee Agricultural Experiment Station, Knoxville 16, Temn.
Because of the increased use of fluoric materials as insecticides and as fertilizers, and because of the distinctive reactivities of various fluoric materials after their incorporation into soils, it seemed imperative to determine the effects that incorporations of various solid carriers exert upon fluorine content in vegetation and in drainage waters. Until experimental inputs were at rates far greater than those to be expected in practice, no carrier induced significant enhancement in the fluorine content of either crops or drainage waters. The fluorine of rock phosphate was virtually inert. Incorporated at abnormal rate, sodium combinationsyielded fluorine leachings beyond those
that passed from magnesium fluoride and cumulative inputs of sodium proved more harmful to soil structure. Rational-rate incorporations of fluorides of sodium and magnesium, and cryolite, can be used without adverse effect upon plant growth, upon uptake of fluorine, and without causing harmful concentration of fluorides in the soil drainage. Those effects hold in particular for incorporations of rock phosphate, without restriction as to rates. In making heavy-rate incorporations for insecticidal effects in the soil, it was demonstrated that the several industrial fluorides possess distinctive pmperties that should govern choice, quantity, and mode of input.
T
and ( 6 ) the occurrence of fluorine in the rain water leaching8 therefrom, under cropping and from fallow, in parallel. Because fluorine does not and cannot occur in elemental state in nature, the word fluorine in the text connotes the presence of that element as a component.
HE meager incidence of fluorine in cultivated soils has been
augmented through incorporations of phosphatic fertilizers, by dustings of fluoric insecticides, and also by the nugatory increments t h a t are brought by rain waters (6). Provision for determination of the fluorine content of soils was not included in the methods for soil analyses and few findings for such content have been recorded ( 1 , 4, 13, 18, 20, S I ) . Only recently was i t established that the fluorine content of a limed analytical charge of soil may be dispelled completely when the charge is calcined as a step preliminary to distillation from perchloric acid (10,1 1 ) . I n recent years, however, attention has been directed to the effects that additive fluoric materials may induce in the soil (8, 10, 13, 18) and upon plant uptake of fluorine therefrom (26l r , 19). Question arose as to whether the “reveision” that component fluorides induce in the processing of phosphatic fertilizers (6-8) ensues also after their incorporation into the soil (9, 11 ). One contribution dealt with the fate of barium silicofluoride incorporations ( 1 3 ) . Recent findings revealed that the nature of the additive carriers governs the leachability of the fluorine ion from its combination with calcium in the soil (12, I d ) , and also the migration of that ion from soil into vegetation (16, 17 j. The effects that additive fluorides exert upon uptake of fluorine from nutrient solutions ( 3 ) and from additives of sodium fluoride were dealt with in recent papers from the New Jersey Station ( l a ) . The present paper reports ( a ) the extent to which incidence of fluorine in three successive crops was affected by separate equivalent incorporations of four fluoric solids, and by rock phosphate on two representative soils that were limestoned at rational rates,
EXPERIMENTAL
FLUORINE CARRIERS. Cryolite (Na3AIF6), magnesium fluoride ( MgFZ), sodium fluoride (NaF), sodium silicofluoride (.Na2SiFG), and rock phosphate were incorporated to supply identical inpu$ of fluorine. Carrier content of fluorine and its occurrence in the crops and in the lysimeter leachings were determined b y means of the Willard and Winter titration technique on the respective distillates (39). SOILS. Clarksville silt loam and the Hartsells h e sandy loam were used. Their properties are given in Table I. The initial pH values of 5.9 and 5.2 were raised to final values of 6.1 and 5.9 as the respective effects from the full-depth incorporations of 3 tons and 4.5 tons of high-calcic limestone per 3,000,000pounds of soil. Both soils reccived full-depth inputs of potassium eulfate
TABLE I. PROPERTIES OF THE SOILSUSED Determinations k:change capacitya me. Exchangeable Ca +’Mg, me. Exchangeable H , me. Fluorine, p.p.m. a By means of ammonium acetate.
Clarksville Silt Loam 5.9 5.6
2.8
2.8 160
Hartsells Fins; Sandy Loam 5.2 10.2 1.0 9.2 169
INDUSTRIAL AND ENGINEERING CHEMISTRY
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Vol. 43, No. 8
cryolite, sodium and magnebium fluorides, and sodium silicofluoride induced larger Soybeans Lespedeza Oats -__ Total Final crops of lespedeza on the Dry Fluorine Dr Fluorine Dry Fluorine Dry ReacHartsells soil, which suggests a weight. content, weigh, content, weight, content, R7eight, tion, I ni*orporationsa piamb p.p.m. grams p.p.m. grams p.p in. Grams pH benefit from a build-up of the Clai ksville Silt Loam concomitant sodium ion. Occurrence of fluorine in the lespedeza was not increased significantly by the fluorides, or by rock phosphate, on either soil, although the initial 150Hnrtsrlls Fine Sandy Loam pound fraction of the additive 408 333 100 h‘one 841 6.9 fluorine present in the upper 415 136 397 Cryoilre 947 6.0 155 66 319 Roch phosphate 540 5.9 half of soil had been augmented 428 361 107 MgF* 896 6.1 408 122 424 Na I: 954 through subsequent input of 6.1 409 118 384 TabsSlF‘a 911 6.9 h75 pounds into that zone. 20 19 28 1,eaPt significant diff., 57, level ... ... The only significant ina F.ach material supplied full-depth I i i i i i i t of 300 pounds of fluorine per 3,000,000 pounds of soil before the seeding of the soybeans and 675 pounds to the upper half of the 9-inch stratum of soil before the seeding of lespedeza crease in the growth of oats the second crop after which the full placement of soil was removed and mixed before the seeding of the third crop: which waq subjLcted to virtrially all of the 976 pounds of fluorine per acre or in 3,000,000 pounds of soil. was that induced by the cryolite on the Hartsells roil. lncidence of fluorine in the oat crops was virtually a constant equivalent to 150 pounds of potassium oxide per acre, and also for all fluorine carriers, and for the no-fluorine controls, on both fluorine-free monocalcium phosphate to supply phosphorus pentsoils. As diff’erlngfrom the higher occurrence of 825 pounds (one oxide a t the 240-pound rate in all unit8 other than those into half of 300 675), or 550 parts per million (p.p.m.) of additive which rock phosphate waB incorporated. fluorine in the upper half of the soil during the growth of the lcspeLYSIMETERS.The lysimeters mere of galvanized iron, asphaltum-coated, 1-foot deep, and mere l/lO,OOO acre in area. deza, the dksemination of the entire 975 pounds into the full The upper and lower halves of each 300-pound placement of depth of soil meant that the oats were grown in soil systems soil, moisture-free basis, were demarcated by means of a disk of whose additive fluorine content was 325 p.p.m. minus the respecl/rinch mesh asphaltum-coated wire “cloth.” Four lysimeter8 tive quantities that passed into the leachings recorded in Table 111. were allocated to every fluorine carrier on both soils; three wen. to be cropped successively, hut the fourth lysimeter was to be The %crop aggregates show significant increases for the rekept, fallow throughout. sponses to the incorporations of cryolite, magnesium fluoride, FLUORINE INPUT,The fiuorine input was a t the 300-pound sodium fluoride, and of sodium silicofluoride on the Hartsells soil; rate for the initial incorporation of each fluorine carrier, on both but the only aggregate increase on the Clarksville silt loam was soils. After the first harvest and just before the seeding of the second crop, another input of each carrier was incorporated into that induced by the incorporation of cryolite. On both soils, the the upper half of each soil a t the rate of 675 pounds of fluorine per over-all growth of crops from rock phosphate, which supplied acre of surface. The intention was that the ultimate content of 2600 pounds of phosphorus pentoxide per acre, was less than the Huorine in the 9-inch depth 0.f each soil would proximate the yrowt,h on the no-fluorine controls that received the 240-pounds fluorine content of the Maury silt loan^ that occurs on the Middle Tennessee Station. After the failure of a September seeding to of phosphorus pentoxide as monocalcium phosphate arid limealfalfa and after the lespedeza had been harvested, the entire stone. The niaxiinal 3-erop uptake of fluorine from the fluoric placement of soil of each tank was removed, mixed thoroughlv, materials was equivalent to l / ~pound p w acre on the Clarltsville and replaced. Hence, the over-all input of 975 pounds of fluorine silt loam and pound on thp Hartsells fine sandy loam. per 3,000,000 pounds of soil, and per acre surface, had been dispersed throughout the 9-inch depth before the seeding of spring oats, the third crop. OUTGO OF r i m o R i n E IN RAIN WATER LEACHINGS CROPS. Soybeans were grown in the sunimer of 1948, immediThe leachings of fluorine from the 300-pound inputs during the ately after the 300-pound initial full-depth inputs of fluorine. As noted, a succeeding growth of alfalfa was discarded, because of its initial gear and the 2-year outgo from the 975-pound inputs are poor growth during the winter, and a second input of each of the recorded in Table 111. Every fluorir material caused an increase four fluorides, and of rock phosphate, was incorporated into the of about 3 pounds of fluorine in the year’s leachings from the 300upper-half zone of both soils in the spring of 1949, and before the pound input on the Clarksville soil, but the rock phosphate inseeding of the lespedeza. The soils then were reworked after that crop, as detailed under ‘‘the fluorine inputs.’’ Alfalfa was duced only nugatory increases in the outgo of fluorine from that seeded again in September 1949, but the resultant stand also failed during the winter month8 and spring oats then were seeded on both soils. T A B L E 111. O U T G O O F F L U O R I N E T H R O U G H RAINJ v A T E R LEACHT.+BLE
11. FLUORINE CONCEN’TRATIoXS I K THREE SUCCESSIVE C R O P S ON T W O INCORPORATIONS OF CERTAIN FLUORINE-CARRYING MATERIALS
S O I L S FRO\I
+
CROP
mwcrs
The weights of the cropa and occurrences of fluorine in them are given in Table 11. Crop contents of calcium, magnesium, potassium, nitrogen, and phosphorus pentoxide also were determined, but their occurrenccs are not germane to the present discussion. The uniform input of 300 pounds of fluorine did not cause an increase in the growth of the soybeans and did not increase their fluorine content on either soil Where the fluorine input was supplied as a component of the rock phosphate on the two limestoned soils, the soybeans gave less response to the 800-pound input of phosphorus pentoxide as rock phosphate than to the 240pound input of phosphorus pentoxide as monocalcium phosphate. 1,eupedeza registered significant response to the second addition of every fluoride on the Clarlrsville soil. The second additions of
l N G S FROM I N C O R P O R A T I O N S O F C E R T A I N FLUORINE-CARRYINQ MATERIALS IN Two LIVESTONED A N D CROPPED SOILS
Outgo of Fluorine, Pounds Clarksville Silt Loam From From 300-lb. 975-lb. inputa input 6 0.19 0.80 3.75 18.98 0.22 1.00 3.26 17.45 3.31 32.72 8.03 19.31
Fluorine Additions inputb inputc None 0.27 0.65 Cryolite 1.80 6.62 Rock phosphate 0.42 0.91 MgFz 1.36 4.86 NaF 1.45 7.51 NazSiFs 1.51 5.85 Least significant 0.28 diff., 5 % level 4.90 0.35 1.25 a Because of close concordance i n the quantities of fluorine carried by the leachings from the cropped and the fallow soils, the outgo values are given as means for the respective 4-lysimeter units. b Through three collections of leachings during initial year. c Through four collections of leachings during the second year:
August 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
soil during either year. After 2 years, however, the over-all outgo of about 18 pounds of fluorine had passed from the 975pound inputs that were provided by the cryolite, the magnesium fluoride, and the sodium silicofluoride, whereas there was an incyease of 30 pounds from the sodium fluoride, tbe most soluble of the fluorides. I n each comparison for both periods, fluorine outgo from the Hartsells soil was decidedly less than the corresponding‘ outgo from the Clarksville soil. Sodium fluoride caused the largest release of fluorine to leachings from the 975-pound input on the Hartsells soil. The smaller releases of fluorine to the leachings from the other three fluoric materials were comparable, whereas the leachings from the incorporations of rock phosphate showed only a meager release. Because the leachings of fluorine from the cropped soils %ere virtually identical to those from the fallowed soils, the values for fluorine outgo are given as respective means for the several 4-unit series of lysimeters. The disparity between the migrations of fluorine into the rain water leachings from the two soils, of almost identical fluorine content, is consonant with their inherent characteristics and the integrated replacements of hydrogen b y the calCium of the limestone. The Hartsells line sandy loam had a n exchange capacity almost twice that of the Clarksville silt loam and hydrogen content 3.3 times as great. Release of the fluoric ion to the rain water leachings from Hartsells loam was only a fourth the release of that ion to the leachings from Clarksville loam. SUMMARY
Incorporations of sodium fluoride, sodium silicofluoride, magnesium fluoride, cryolite, and rock phosphate supplied fluorine at a per-acre rate of 300 pounds into 9-inch depth of a IimeBtoned fine sandy loam and a silt loam in 56 lysimeters of ~/,o,ow acre. Of the four lysimeters allocated to each fluorine carrier on each soil three were seeded t o soybeans. After that crop, a further incorporation of each carrier carried 675 pounds of fluorine per acre into the upper 4.5-inch zone of both soils, to which lespedeza then was seeded. Following that crop, each 975-pound input of fluorine per acre was disseminated throughout the 9-inch depth of soil and spring oats were sown. No carrier caused enhancement in the fluorine present in above-ground vegetation on either soil and fluorine content was virtually constant in the soybeans, in the lespedeza, and in the oats on both soils. Outgo of fluorine from the 300-pound inputs as fluorides in the Hartsells soil was small, b u t significant; in contrast was the insignificant outgo from the incorporated rock phosphate. Fluorine retentions b y the more acidic Hartsells soil were about twice the corresponding retentions by the Clarksville soil, which had a higher content of calcium. Substantial increases in fluorine outgo occurred after the 675pound supplement was mixed into the 9-inch depth of both soils; but, the mean for 2-year outgo of fluorine from the 975-pound input into Hartsells was still only a fourth or third as much as the corresponding mean for Clarksville soil. Maximal concentration of ffuorine in the year’s leachings from the 300-pound input was 0.43 p.p.m. ‘for Hartsells, and 0.96 p.p.m. for Clarksville, against corresponding concentrations of 1.18 p.p.m. and 5.18 p.p.m. in the second year’s leachings from the 975-pound full-depth incorporations.
17%
The largest leaching of fluorine per acre was 32.7 pounds from the 9i6-pound input as sodium fluoride in Clarksville, and the lwrcr lcachings from the over-all incorporations of cryolite, magiipsium fluoride, and sodium silicofluoride in each soil were so alike that respective differences in fluorine outgo were not deemed significant. Fluorine outgo was not affected by the growing of the crops. CONCLUSION
On soils of humid regions and of the types used in the foregoing study, rational uses of fluoric insecticides, or incorporations of either superphosphate, rock phosphate,. or slag do not induce significant enhancement in fluorine content of above-ground vegetation, nor do such uses impart to ground water a harmful concentration of fluorides. ACKNOWLEDGMENT
The authors wish to acknowledge W. M. Shaw for the determinations of the exchange capacity of the soils as given in Table I. LITERATURE CITED
Bartholomew, R. P., Soil Sci., 40, 203-17 (1935). Hart, E. B., Phillips, P. H., and Bohstedt, Am. J. Public Health, 24. 936-40 (1934).
Leone, I. A., Brenan, E. G., Daines, R. H., and Robbins, W. R., Soil Sci., 66, 259-67 (1948). MacIntire, W. H., Ibid., 59, 105-9 (1945). MacIntire, W, H., and Associates, IND. ENQ.CHEM.,41, 246675 (1949).
MacIntire, W. H., and Hardin, L. J., Ibid., 32, 88-94 (1940). Maohtire, W. H., Hardin, L. J., and Oldham, F. D., Ibid., 28, 48-57 (1936).
MacIntire, W. H., Hardin, L. J., Oldham, F. D., and Hammond, J. W., Ibid,, 29, 758-66 (1937). MacIntire, W. H., and Hatcher, B. R., Soil Sci., 53, 43-54 (1942).
MacIntire, W. H., Jones, L. S., and Hardin, L. J., J. Assoc. Ofic.Agr. Chemists, 33, 654-63 (1950). iMacIntire, W. H., and Palmer, G., J. Assoc. Ofic.Agr. Chemists, 31, 419-21 (1948).
MacIntire, W. H., Shaw, W. M., and Robinson, B., Soil Sci., 67, 377-94 (1949).
MacIntire, W. H., Shaw, W. M., and Robinson, B., Univ. of Tennessee Agricultural Expt. Sta., Bull. 155 (1935). MacIntire, W. H., Shaw, W. M., Robinson, B., and Sterges, A. J., Soil Sci., 65, 321-41 (1948). MacIntire, W. H., Winterberg, S. H., and Clements, L. B., Soil Science SOC.Am., Proc., 10, 71-80 (1945).
MacIntire, W. H., Winterberg, S. H., Clementa, L. B., and Dunham, H. W., Soil Sci., 63, 195-207 (1947). MacIntire, W. H., Winterberg, S. H., Thompson, J. G . , and Hatcher, B. W., IND. ENG.CHEM.,34, 1469-79 (1942). Nagelschmidt, G., and Nixon, H. L., Nature, 154,429-30 (1944). Prince, A. L., Bear, F. E., Brennan, E. G., Leone, I. A., and Daines, R. H., Soil Sci., 67, 269-78 (1949). Robinson, W. O., and Edington, G., Ibid., 61, 341-53 (1946). Stenkoenig, L. B., IND.ENQ.CHEM.,11, 465 (1919). Willard, H. H., and Winter, 0. B., IND. ENG.CHEM.,ANAL.ED., 5, 7-10 (1933).
RECEIVED October 26, 1950. Presented before the Division of E’ertilizer Chemistry at the 118th Meeting of the AUERICANCHEMICAL SOCIETY, Chicago, Ill. The reported findings were obtained through studies conducted in the Department of Chemistry of The University of Tennessee Agricultural Experiment Station in collaboration with Tennessee Valley. Authority, Divisions of Chemical Engineering and Agricultural Relations.
