SOILS FEETILIZEES. 



417 



(E. S. R., 20, p. 919), the amount and form of nitrogen and the amount of 

 various mineral constituents in soil water under varying conditions of season, 

 cultivation, and manuring were studied. 



The results confirm those of previous experiments in showing that in a dry 

 season there is almost no ammoniacal nitrogen but a relatively high proportion 

 of nitric nitrogen in soils, but that when the rainy season begins the conditions 

 are reversed. It was found that calcium salts were more quickly and com- 

 pletely precipitated when soil solution was evaporated in air nearly free from 

 carbon dioxid than in an atmosphere charged with this gas, as is the condi- 

 tion in soils supplied with a sufficient amount of organic matter, thus emphasiz- 

 ing the importance of keeping the soil well supplied with organic matter. 



The effects o^ cultivation and of manures on the soil of the manurial ex- 

 periment fields, J. B. Harrison, F. A. Stockdale, and R. Wakd (West Indian 

 Bui., 13 {1912), No. 2, pp. UO-m).— It was ^ound that the normal alkalinity 

 of these soils was increased by cultivation and by the action of certain chemi- 

 cal manures. Long continued cultivation produced excessive alkalinity in 

 the capillary waters of the soil and reduced the growth of crops. The incor- 

 poration of organic matter in the soil tended to increase the carbon dioxid and 

 thus to hold the salts of lime, in solution. Continuous use of nitrate of soda 

 in heavy applications injuriously affected the physical properties and pro- 

 ductiveness of the heavy clay soils. On account of the high alkalinity of the 

 soil ammonium sulphate has given better results than sodium nitrate. Long 

 continued cultivation improved the texture of heavy clay land. The judicious 

 use of natural and artificial manures increased this effect, the upper layers of 

 the soil tending to become lighter in texture. 



Observations on soil inoculation, J. G. Lipman (Proc. Soc. Prom. Agr. ScL, 

 S3 {1912), pp. 69-15). — Summarizing observations largely made at the New 

 Jersey Stations, the author concludes that soil inoculation is made more effec- 

 tive by so modifying the soil as to make it a fit culture medium for legume 

 bacteria by the use of lime, readily available mineral fertilizers, and green 

 manures or animal manures. 



Influence of humus as well as carbon dioxid fertilizing on the growth of 

 plants, L. HiLTNEB {Prakt. Bl. Pflansenbau u. Schuts, n. ser., 11 {1913), No. J,, 

 pp Ji5-52, fig. i).— This is a critical review of work by Krantz, based upon 10 

 years' investigation along similar lines by the author, and emphasizing espe- 

 cially the fact that the action of humus and the processes to which it gives 

 rise in the soil are important factors in determining the effectiveness of other 



fertilizers. 



Fixation of nitrogen by alumina and carbon, S. A. Tucker and H. L. Read 

 (Trans. Anwr. Electrochevi. Soc, 22 (1912), pp. 51-66, figs. 2).— This is the 

 full text of a paper, an abstract of which has already been noted (E. S. R., 



28, p. 222). 



Air nitrate, G. Beion (Luftsalpeter. Berlin and Leipsic, 1912, pp. 154, flffs. 

 /;(;). _This book describes and explains the principles underlying electrical 

 methods of preparing nitrogen compounds from the air. It contains a bibli- 

 ography of 87 references to the literature of the subject. 



The percentage of total phosphorus in flat turnips as influenced by the 

 amount available in soils, B. L. Hartwell (Rhode Island Sta. Bui. 154, pp. 

 121-148).— This bulletin is based mainly upon chemical studies of samples of 

 flat turnips grown in cooperative experiments with farmers in different parts 

 of the State to determine the phosphorus requirements of the soils. 



" It was found that in similar seasons the percentage of phosphorus in the 

 turnips from the different soils usually varied in the same direction as the 

 amount of available phosphorus in the soil ; and it seems probable, especially 



