426 EXPERIMENT STATION RECORD. [Vol. 41 



soluble phosphate and the remainder as insoluble phosphate the average result 

 is as good as when the whole of the phosphoric acid is given as soluble phos- 

 phate. Experiments with other crops and especially with grass give a similar 

 result. The only conclusion one can come to is that soluble phosphate is over- 

 valued, and insoluble phosphate, such as exists in basic slag and ground mineral 

 phosphate, undervalued. It should be possible in future to use a large part 

 of the rock phosphate in tlie form of finely ground powder instead of in super- 

 phosphate. This will effect a great saving in acid and in expense." 



American potash, H. H. Roe {Mining and Sci. Press, 119 {1919), No. 6, pp. 

 195-202, figs. 11). — This is a summary of the various potash resources of the 

 United States, from which it is concluded that this country has potash resources 

 sufficient for future requirements but that the present supply will for some time 

 to come be inadequate for the growing demand. 



The Alsatian potash industry, F. K. Cameron {Amer. Fert., 51 {1919), No. 4, 

 pp. fi9-5'f). — It is stated that the Alsatian potash deposits cover an area of 

 about 77 square miles, and consist of a lower bed with an average thickness of 

 11.5 ft. and an upper bed with a thickness of about 4 ft. The cubical contents 

 of the two layers are estimated at approximately 1,350,000,000 cu. yds., con- 

 taining approximately 1,500,000,000 tons of salt, or roughly 275,000,000 tons of 

 potash. The soluble salts of the deposits are potassium and sodium chlorid 

 alone, and the average potash content is said to be at least 18 per cent as com- 

 pared to 12 per cent for the Stassfurt salts. 



While the industry is too young to give accurate cost figures, an approximate 

 estimate indicates that for potassium chlorid averaging 18 and 45 per cent 

 potash, respectively, the cost is $11.00 and .$28.75 per ton. 



Features of the mining and manufacturing processes are described. 



The value of sodium when potassium is insufficient, B. L. Hartwell and 

 S. .C. Damon {Rhode Island Sta. Bui. 177 {1919), pp. Jt-32. fig. i).— This bulletin 

 reports the crop results for the period of 1905-1918, inclusive, of a series of 

 field experiments begun in 1894 to ascertain the value of sodium as an entire or 

 partial substitute for potassium and previously noted from time to time (E. S. 

 R., 18, p. 1113; 21, p. 224; 29, p. 419). Sodium and potassium were applied in 

 various amounts, both as carbonates and chlorids and in connection with dif- 

 ferent amounts of lime. Kitrogen and phosphorus were applied equally to all 

 plats, usually in such amounts as to render potassium the only deficient element. 

 The crop data are presented in tabular form, and include information on the 

 effect of the different treatments upon flat turnips, radishes, rutabagas, table 

 beets, cucumbers, buckwheat, cabbage, sugar beets, mangels, oats, hay, onions, 

 carrots, rape, and potatoes. The results secured may be summarized as follows : 



Where an insufficiency of potassium occurred, sodium was generally useful, 

 confirming earlier work with water cultures of cereal seedlings, which likewise 

 showed that when potassium was deficient sodium became beneficial. It was 

 commonly observed that if in the absence of sodium a depression of 30 per cent 

 in the growth of the seedlings was caused by partially withholding potassium, 

 the growth was not depressed more than half as much in a similar culture to 

 which sodium was added, indicating a direct beneficial action of sodium, for 

 under the conditions of the experiment it could not liberate potassium. In the 

 field, however, more potassium was removed in the larger crops which usually 

 resulted when sodium was increased in connection with an insufficient amount 

 of potassium, in spite of the fact that sodium frequently decreased the per- 

 centage of potassium In the crop. A portion of the benefits arising from the use 

 of sodium in the field is, therefore, believed to be due to indirect action, although 

 the culture solutions indicate that direct beneficial effects were also probably 

 obtained in the field. The yield in grains due to sodium are deemed suflicient to 



