1917] SOILS — FERTILIZEKS. 119 



the soil permits more uniform diffusion and movement of nitrates into the sub- 

 strata. 



Comparison of the nitrifying' powers of some humid, and some arid soils, 

 C. B. LiPMAN, P. S. BuKGESs, and M. A. Klein {U. S. Dept. Agr., Jour. Agr. 

 Research, 7 {1916), No. 2, pp. 47-82).— Studies conducted at the California Ex- 

 periment Station on the nitrifying powers under incubator conditions of about 

 40 humid and 150 arid soils, of which at least one sample was obtained from 

 each State in the Union, are reported. " The soil was used as a medium, and 

 the forms of nitrogen employed were soil nitrogen, sulphate of ammonia plus 

 soil nitrogen, dried blood plus soil nitrogen, and cottonseed meal plus soil 

 nitrogen." 



It was found that the nitrifying powers of soils of the arid region are no 

 more intense than those of the humid i-egion. It is considered possible that 

 " the data [for soil nitrogen and dried-blood nitrogen] justify the further con- 

 clusion that the nitrifying powers of humid soils are greater than those of 

 arid soils. . . . Arid soils nitrify the nitrogen of sulphate of ammonia and 

 cottonseed meal with much greater vigor than do the humid soils. A reversal 

 of efficiency is manifest between the two groups of soils as regards sulphate of 

 ammonia and cottonseed meal on the one hand and dried blood and soil nitro- 

 gen on the other." 



The washing out of nitrate from arable soil during the past winter, E. J. 

 Russell and A. Applet akd (Jour. Bd. Agr. [Londmi], 23 (1916), No. 1, pp. 22-27, 

 figs. 2). — Studies of the soils of several experimental fields after an unusually 

 wet winter showed that the high winter rainfall caused a deflocculation of clay 

 and a depletion of the stock of soil nitrates. 



Experiments on the improvement of peat soils by adding mineral soils 

 and lime, H. von Feilitzen (Svenska MosskuUiirfor. Tidskr., 29 (1915), No. 6, 

 pp. 462-466). — In experiments at Flahult it was found that the addition of a 

 mixture of sand and loam to swamp soil increased the yield of hay. When 

 sand alone was used better results were obtained with oats, timothy, and pas- 

 ture grass when the sand was spread on the surface than when it was plowed 

 into the soil. Turnips and flax responded best to liming on these soils and red 

 clover and barley least. 



Manuring for higher crop production, E. J. Russell (Cambridge, Eng.: 

 Univ. Press, 1916, pp. [17] +69, p?«. 2, figs. 14). — This is a popular book for 

 English farmers on manures and soil management, which is intended especially 

 to meet emergency conditions due to the European war. It is divided into five 

 chapters. 



Chapter 1, the improvement of the soil, deals with cultivation, liming, green 

 manuring, and catch cropping. Chapter 2, the manure heap, deals with the 

 storage, conservation, use, and time of application of manure and liquid 

 manure. Chapter 3, artificial manures, deals with the composition and use of 

 the well-known nitrogenous, phosphatic. and potassic fertilizers. Chapters 4 

 and 5 deal in turn with the practical manuring of arable land with reference 

 to different common crops and the manuring of grass land. 



Fertilizers, E. B. A'oorhees (Neio York: The Maemillan Co., 1916, rev. ed., 

 pp. XV-\-365, pis. 16, figs. 6). — This is a revised edition of this book by J. H. 

 A'oorhees (E. S. R., 10, p. 942). The revision consists of the rearrangement 

 of certain parts, the Incorporation of considerable new matter, and the bring- 

 ing up to date of old matter. A chapter on manures is included ; the subject 

 of lime is more fully treated ; and more attention is given to the utilization 

 of various by-products and waste products as fertilizers as well as to recently 

 discovered phosphates and phosphate preparation, air nitrogen compounds, and 



