1919] SOILS FERTILIZEKS. 519 



conditions, witli tlio siliceous material originally occurring in the raw mis, and 

 (3) to a partial decomposition of the silicates of the raw mix and also of any 

 coal ash which is carried over mechanically in the dust. The acid-insoluble 

 potash in cement dust is due to undecomposed silicates and coal ash carried 

 over mechanically in the dust, and to a recombination of the volatilized potash 

 with the ash of the coal when the amount volatilized is low. 



" The portion of the potash in the dust which has undergone recombination is 

 of the nature of a potash slag or impure glass. When the amount of potash 

 volatilized is low, and particularly in the presence of carbon, some recombina- 

 tion may take place with the siliceous material of the raw mix as well as that 

 of the ash. It is probable that the extent of the recombination would be reduced 

 if the burning of the cement were done under oxidizing rather than reducing 

 atmospheric conditions. The extent of recombination would also probably be 

 reduced by any procedure that would introduce lime or sodium chlorid into the 

 dust at the hottest part of the kiln. The greater the amount of potash 

 volatilized, the lower will be the proportion that will undergo recombination in 

 the dust." 



German potash industry during the war, P. L. Edwabds (U. S. Dept. Com., 

 Com. Rpts., No. 213 (1919), pp. 1331-1338).— This, report indicates that the pro- 

 duction of potash salts in Germany during the war was not so abnormally low 

 as was generally believed, due to increased domestic consumption and exports 

 to the allies of Germany. The total productions of crude potash in 1915, 1916, 

 and 1917 were 7,567,424, 9,507,176, and 9,832,612 short tons, respectively, as 

 compared to 12,768,262 short tons in 1913. During 1917 Germany used 917,820 

 tons of actual potash in agriculture as compared to 589,713 tons used in 

 1913, and during 1917 a total of 1,056,929 tons of German potash was used in 

 agriculture. 



Fertilizer experiments with increasing amounts of potash, on lowland 

 moor soils with cabbage and potatoes, I— II, A. J. Werth {Mitt. Ter. Ford. 

 Moorkult. Deut. Reiche, 36 (1918), Nos. 17, pp. 305-310; 18, pp. 317-321, fig. 1).— 

 Plat experiments with cabbage and potatoes on lowland moor soils, in which 

 26 and 40 per cent potash salts were added at rates of 243, 486, 729, and 972 

 lbs. per acre, are reported. The purpose was to determine the most efficient 

 additions of potash salts on these soils. 



The addition of 486 lbs. of 40 per cent salts per acre to cabbage did not 

 give the highest yield. The addition of 729 lbs. materially increased the yield, 

 and in some cases the highest yield was obtained with the 972-lb. addition. 

 It is thought that a residual effect may be expected from the constant potash 

 fertilization of such moor soils, liut the effectiveness of greater additions 

 than those noted is considered doubtful. 



With potatoes additions of 324 to 405 lbs. per acre of 40 per cent salts did 

 not give maximum results. It is thought that additions of 486 to 567 lbs. of 

 40 per cent salts or 648 to 729 lbs. of 26 per cent salts will give better results 

 generally, but a depression is noted for greater additions. Even though a de- 

 pression in crop occurs it is thought that the i-esidual effect of larger additions 

 will be compensating. 



The injurious effects of potash and sodium salts upon the soil structure 

 and their cause, G. Hager (Jour. Landic, 66 (1918), No. 4, jyp. 2^1-286, fig. 1). — 

 Experiments on the effect of potash and sodium salts on soils are reported in 

 which it was found that weak acids have a tendency to split off the combined 

 bases in soils as hydrates. The bivalent cations, lime and magnesium, have a 

 favorable influence on the soil structuie, while the monovalent, sodium and 

 potassium, have an unfavorable influence. 



