1916] SOILS FERTILIZEES. 813 



the beginning to tlie present date witli two of the tanks, while with the other two 

 the highest point was reached in 1914. . . . The losses of lime and sulphate are 

 still increasing." 



Water table variations, causes and effects, A. B. Ballantyne {Utah Sta. 

 Bui. lU U916), pp. 23, figs. J6).— This bulletin reports the results of 1,111 

 measurements, by means of wells, of the water level variations in a soil de- 

 scribed in a previous report by Widtsoe and Stewart (E. S. R., 29, p. 18), the 

 purpose being to show the effect of rainfall and irrigation water at different 

 seasons and the influence of the water level variations on soil and vegetation. 



It was found that the level of the free soil water was lowered by natural 

 drainage, surface evaporation, and growing vegetation. " The normal precipi- 

 tation caused it to rise, the amount depending upon the distance of the free 

 water from the surface and the quantity of rain falling, small amounts show- 

 ing no appreciable influence." Long continued irrigations caused the water 

 level to rise, the rise being greatest where the free soil water was nearest the 

 surface, but apparently depending upon the length of time the stream was 

 allowed to run on the land. " The fluctuation of the water level caused by 

 heavy applications of water followed by long dry periods . . . caused the death 

 of large numbers of trees and vines ; the first of the former which died were 

 those where the water was confined to two or four narrow furrows . . . made 

 close to the trees. The ones that were alive to the last were on those parts 

 flooded by the regular irrigations. It lessened the lucern field's production to 

 less than one-fifth of its former normal yield. Crops of oats grown after the 

 lucern at no time produced more than half crops. The application of less 

 water more rapidly applied is indicated as the logical remedy for this seeped 

 condition." 



The relation between absoi'ption and coagulation and its importance in 

 soil, A. DE DoMiNicis {Staz. Sper. Agr. Ital., 48 (1915), No. 8, pp. 525-555; abs. 

 in Chem. Zenibl., 1915, II, No. 26, p. 1307; Jour. Chem. Soc. [London], 110 

 {1916), No. 641, I, p. 24O). — Experiments with clay are reported which led to 

 the following conclusions : 



The phenomena of absorption and coagulation proceed together, and a change 

 in one is always accompanied by a simultaneous, analogous change in the other. 

 For instance, the coagulating powers of different ions correspond with their 

 degrees of absorption. Absorption effects a retrogression of the colloids, a 

 diminution of the difference of electrical potential between the contrasted 

 phases, and a rise in the surface tension, the phenomenon of coagulation thus 

 making its appearance. 



Soil colloids, P. RoHLAND {Landw. Vers. Stat., 88 {1916), No. 1-2, pp. 121- 

 129). — A further discussion is given dealing mainly with the adsorptive powers 

 of clay, lateritic, and red soils (E. S. R., 32. p. 318). 



Bacteriological studies of a soil subjected to different systems of cropping 

 for twenty- five years, P. L. Gainey and W. M. Gibbs {U. S. Dept. Agr., Jour. 

 Agr. Research, 6 {1916), No. 24, pp. 953-975, fig. i).— Studies conducted at the 

 Missouri Experiment Station of the bacterial numbers and ammonia and 

 nitrate-forming powers of a silt loam soil, part of which has been in continuous 

 culture to specific crops and part subjected to varying fertility treatment for 

 25 years, are reported. 



It was found that the soil under continuous corn and wheat contained, in 

 the absence of any additions of fertilizers or manure, relatively low numbers of 

 bacteria. In the presence of manure, continuous corn and wheat soils con- 

 tained relatively high numbers, manure having a much more marked effect 

 upon numbers here than under the other crops studied. No appreciable effect 

 upon the ability of the soil to liberate ammonia from cotton-seed meal was 



