134 EXPERIMENT STATION RECORD. 



25 {1910), Nos. 4, PP- 46-^9; 5, pp. 61-67, figs. 10).— In pot experiments with 

 oats, rye, beans, potatoes, and clover, extending over two years, 1908 and 1909, 

 the 40 per cent potash salt gave much larger yields than either the silicate or 

 feldspar, the latter showing no increase whatever, whereas the silicate gave a 

 slight increase in yield. Ammonium sulphate applied with the phonolite did 

 not increase the solubility of its potash, and there was no beneficial after-effect 

 of the potassium silicate the second year. 



The utilization of the potash in lime trass fertilizer, A. Stutzeb {Mitt. 

 Deut. Landio. Gesell., 25 {1910), No. J,3, pp. 621, 622).— This article refers to 

 experiments by Remy comparing a patented so-called zeolite fertilizer with 

 phonolite, and reports pot experiments by the author to determine the efficiency 

 of this fertilizer in comparison with potassium chlorid and sulphate on peas 

 and barley. 



The results show that taking the utilization of the potash of the chlorid as 

 100, that of the trass fertilizer was 17 with peas and K) with barley. 



The society for the scientific advancement of the German potash salts 

 deposits, J. H. Van't Hoff {Sitzher. K. Preuss. Akad. Wiss., 1910, XXXIX, 

 pp. 772-7S6). — An annotated list of recent papers and documents bearing upon 

 the German potash salts deposits is given. 



Experiments with phosphatic fertilizers, W. Schneidewind and D. Meyer 

 (Landw. JaJirb., 93 {1910), Ergdnzungsh. 3, pp. 236-247; abs. in Cliem. Zenthl., 

 1910, II, No. 6, pp. 405, 406; Jour. Soc. Chem. Indus., 29 (1910), No. 17, p. 

 1070). — Comparative pot tests of superphosphate, Thomas slag, "agricultural 

 phosphate," and precipitated phosphate are reported, as well as studies of 

 the I'ate at which these phosphates become available in the soil and of their 

 behavior in combination with other fertilizing materials. 



The soil used in these experiments was sandy clay loam mixed with about 

 1 per cent of lime. It had not received any phosphatic fertilizer for many 

 years. The crops grown in the experiments were oats and mustard. 



In soils with a good lime content, with only a little iron and clay, the Thomas 

 slag as well as the superphosphates and the precipitated phosphate retained 

 their effectiveness for many years. In the first two years the excess applica- 

 tion of superphosphate gave better returns than the same application of Thomas 

 slag; in the third, fourth, and fifth years both phosphates yielded the same; 

 but in the sixth and seventh years the Thomas slag yielded more than the 

 superphospate. Greater amounts of phosphorus were assimilated by the plants 

 in seven years from the excess application of the superphosphate than from the 

 Thomas slag. This greater assimilation occurred mainly during the first year. 

 The phosphoric acid of the Thomas slag was more economically utilized by the 

 plants than that of the superphosphate. 



The so-called agricultural phosphate showed only a slight action, and only 

 a small quantity of the phosphoric acid was available. Its efficiency as com- 

 pared with that of the Thomas slag was only 18.6 per cent. 



The mixing of lime nitrogen with the superphosphate reduced the efficiency 

 of the latter. 



The occurrence of phosphorus in Curagao, Aruba, and Bonaire {Indisclie 

 Mercitur, 33 {1910), No. 42, pp. 839, 840). — An account of the present status of 

 the phosphate mines of these islands, and a description of small phosphate de- 

 posits discovered in 1909 near Banki Jessurun, Aruba, are given. Samples of 

 the new deposits contained about 77 per cent of calcium phosphate. 



Experiments with lime and mag'nesia, D. Meyer {Landw. Jalirh., 39 {1910). 

 Ergdnzungsh. 3, pp. 254-298, fig. 1; abs. in Chem. Zentbl., 1910, II, No. 6, p. 406; 

 Jour. Hoc. Chem. Indus., 29 {1910), No. 17, p. 1071). — The subjects investigated 

 in these experiments were the relation of the yield of crops to the ratio of lime 



