1918] 



SOILS FERTILIZERS. 



327 



States reported a production in 1916 of 35,739 short tons, having a mean con- 

 tent of about 27 per cent potash (K2O) and a total content of 9,720 short tons 

 of potash (K2O). This is almost exactly ten times the production reported for 

 1915." The reports for all forms are reduced to tons of available potash in the 

 following table: 



Summary of potash produced in 1916. 



Source. 



Available potash (KiO). 



Quantity. 



Value at 

 point of ship- 

 ment. 



Natural salts or brines 



Alunite and silicate rocks. Including recoveries through fumac* dust 



Kelp 



Wood ashes (potashes, pearlash) 



Distillery waste (molasses) 



Miscellaneous organic sources 



Short tons. 

 3,994 

 1,850 

 1,556 

 412 

 1,845 

 63 



81,937,600 

 715,000 

 781,100 

 270,000 

 500,900 

 38, 130 



9,720 



4,242,730 



" The largest output has come from the alkali lakes in western Nebraska, 

 which have afforded the most readily available supply of moderately high- 

 grade potash salts obtained by direct drying of the raw material, with per- 

 haps as few technical complications as could be involved in any chemical opera- 

 tion. The great deposit at Searles Lake is only just being brought to the pro- 

 ducing stage, the project there having undergone many reverses, technical 

 and otherwise. The production from alunite has been rather regular, but has 

 shown little expansion. Some progress has been made in the extraction of 

 potash from silicates, at least one plant having made and marketed a special 

 product. A large quantity of feldspar has been mined, ground, and so treated 

 that a small percentage of its potash was rendered soluble and so available for 

 use in fertilizers, but none of it is included in the figures for 1916, as little of 

 it was marketed in that year. So far as known, no leucite rocks or mica or 

 sericite schists or similar rocks having a large content of potash have yet 

 yielded any commercial water-.soluble salts. 



" Potash has been produced from several kinds of organic materials. The 

 efforts to obtain potash and potash fertilizers from kelp have been widely 

 published and have been to a certain extent successful. High-grade potash 

 fertilizer salts have been made from molasses distillery wastes in quantities 

 that exceeded the production from kelp. The manufacture of potash from wood 

 ashes by the old-time methods continues to make a small but significant con- 

 tribution to the total production." 



The divergent effects of lime and magnesia upon the conservation of soil 

 sulphur, W. H. MacIntire, L. G. Willis, and W. A. Holding (Soil ScL, 4 

 {1911), No. 3, pp. 231-237, figs. 2).— Experiments at the Tennessee Experiment 

 Station with a mellow sandy loam soil are reported, in which burnt lime, burnt 

 magnesia, precipitated calcium carbonate, precipitated magnesium carbonate, 

 100-mesh limestone, 100-mesh dolomite, and 100-mesh magnesite were added to 

 the soil at rates equivalent to 8, 32, and 100 tons of calcium oxid per acre. 

 Each treatment was thoroughly mixed with moist soil in good, workable condi- 

 tion and placed in a galvanized iron lysimeter containing a sand filter bed and 

 having a block tin drainage tube. In a second set, placed simultaneously, the 

 foregoing treatments were duplicated as to surface soil, but 1 ft. of clay sub- 

 soil was placed between each sand filter and the overlying surface soil. 



