716 EXPERIMENT STATION EECORD. 



[Paris], 48 (1910), I, No. 20, p. 636).— Prianishnikov has shown (E. S. R.. 17, p, 

 842) that muscovite supplies more potash to plants than orthoclase. The author 

 shows that this is due to the greater solubility of the muscovite iu water. Grouud 

 muscovite dissolved at the rate of 0.48 part of potash per 1.000 of water, while 

 more finely ground orthoclase yielded only 0.2 part. The solubility of the pot- 

 ash of muscovite was increased by the addition of gypsum to 1.02 parts, of 

 peat to 1.05 parts, of ammonium sulphate to 1.55 parts, of quicklime to 1.76 

 parts, of 1 per cent citric acid to 1.S5 parts, of monocalcium phosphate to 

 2.24 parts, and of cold concentrated hydrochloric acid to 2.9 parts. 



Examinations of soils of the Rhone Valley showed the presence of from 15 to 

 20 parts per 1,000 of mica yielding 30 parts per 1,000 of potash, yet these soils 

 yielded comparatively little potash to cai'bonated or boiling water, less than that 

 given in a previous note (E. S. R.. 23, p. 121), as indicating the need of potash 

 fertilizers. Still, with the exception of rapidly growing plants like asparagus, 

 potash fertilizers did not increase the effect of superphosphate alone on these 

 soils. The result is attributed partly to the mobilizing effect of the superphos- 

 phate and partly to the power of the roots to assimilate the so-called insoluble 

 potash of the soil. 



It was found in pot experiments that rye grass was able to assimilate potash 

 from mica which had previously been extracted with hydrochloric acid. The 

 author is of the opinion that mica furnishes to plants not only potash but mag- 

 nesia and fluorin, the latter being considered of importance in the nutrition of 

 plants and animals. 



The composition of Ethiopian soils, A. Mazzaron {Agr. Colon. [Italy], 4 

 {1910), Xos. //, pp. .LiO-232, map 1; 5, pp. 263-273). — Analyses of a large num- 

 ber of samples of soils collected iu the drainage basin of Lake Tzana are re- 

 ported and discussed. 



On irrig'ated leucite soils, G. de Angelis d'Ossat {Atti R. Accad. Lincei. 

 Rend. CI. Sci. Fis., Mat. e Nat., 5. set:, 19 (1910), I, No. 9, pp. 575-578; abs. in 

 Clicni. ZcntbL, 1910, II, No. 6, p. 403). — Some of the practical results of previous 

 studies by the author on the amount and solubility of fertilizing constituents in 

 such soils are briefly reviewed. 



Spinach troubles at Norfolk and improvement of trucking soils, L. L. 

 Hakter (Virginia Truck Sta. Bui. //, pp. 61-80, figs. 5). — An account is here 

 given of observations made on the general condition of trucking soils near Nor- 

 folk, Va., iu connection with a study of malnutrition diseases of spinach. The 

 work was an outcome of cooperative experiments by the station and the Bureau 

 of Plant Industry of this Department. The relation of rainfall to disease is 

 briefly considered and the manurial needs of the soil and means of supplying 

 them are discussed in some detail. 



In general it was found that the lack of humus in the soil was the principal 

 fault, analyses showing as low as 0.52 per cent of this substance. To correct 

 this fault the use of barnyard and green manures iu a proper rotation of crops 

 is recommended. The functions of micro-organisms and the relation of lime to 

 the micro-organisms and humus in the soil are discussed. It was found that 

 nitrifying and root tubercle organisms were unable to thrive iu the Norfolk 

 soils and their failure is attributed to the lack of organic matter and the pres- 

 ence of acids in the soil. 



The neg'ative influence of soils upon the nitrogen content of wheat, G. W. 

 Shaw (Abs. in .Science, n. sen, 32 (1910), No. 823, pp. 479, -}S0).— This is an 

 abstract of a paper presented at the San Francisco meeting of the American 

 Chemical Societj', which summarizes the results of experiments with wheat 

 grown at the -California Station on typical soils brought from different wheat 

 growing areas of the United States. The results in general indicate that the 



