

SOILS FERTILIZERS. 321 



The relation between soil, vegetation, and climate on the islands of East 

 Friesland, F. Sciiucht {Intemat. Miti. Bodcnk., 2 {1012), No. 6, pp. 485-532, 

 pis. 3, figs. 2i).— Descriptions are given of the soil, vegetation, and climate of 

 these islands. 



The soils are chiefly sand or very sandy clays, very fine grained, with a lime 

 content varying within wide limits. The soil areas are divided into sandy 

 coast plains, sand dunes, and sand marshes. The sandy plain soils contain 

 much lime, chiefly originating from seashells, the newer dunes somewhat less 

 lime, and the old dunes relatively little. Humus is found only in the very old 

 dunes and in the valley dunes and is seldom over one per cent. These soils 

 are very poor in plant food. The sand marshes with a slime covering support 

 a heavy vegetation compared with that of the dunes, and are relatively rich in 

 plant food, especially lime and humus. 



The salt content of the ground water and of the soils, which is said to come 

 from sea water, exercises a marked influence on the kind and amount of the 

 vegetation of the islands. 



The climate is oceanic, being characterized by a constant temperature, 

 gradual changes from warm to cool and vice versa, high content in the air of 

 'moisture, ozone, and salt, uninterrupted air movement, and much sunshine. 



Demonstration of the law of minimum, S. Goy (Mitt. Dent. Landic. GeselL, 

 28 {1913), No. Jjo, p. 623, fig. 1). — A diagram is given illustrating the law of 

 minimum as applied to growth factors in a soil. 



Evaporation of water from soils, C. B. Lipman {Cal. Country Jour., 29 

 {1913), Nos. 35, pp. 1, Ik; 31, pp. 1, 2; 39, pp. 1, 2).— This is a popular discus- 

 sion of evaporation of water from soils in which the work of numerous investi- 

 gators is briefly reviewed. The effect of soil texture, surface cultivation, and 

 moisture in the air on evaporation from bare soils is pointed out, and means 

 for preventing evaiwration are suggested, such as shading, windbreaks, and 

 protective coverings, including straw, manure, and soil or dnst mulches. At- 

 tention is called especially to the enormous evaporation of water through plant 

 transpiration. 



The presence of arsenic as a normal element of soil, G. Zuccaei ( Gaz. Chim. 

 Ital., 43 {1913), II, No. 4, pp. 598-7,05).— Analyses of 20 soil samples, varying in 

 physical and chemical composition and taken from different depths in different 

 geological formations and at varying elevations, showed an arsenic content 

 varying from 0.1S7 to 6 parts per 100,000 of soil, being largest in soils contain- 

 ing the most iron compounds, and vai-ying almost directly with the iron content. 

 This is ascribed to the greater tendency of arsenic to combine with iron than 

 with other metals. It is thought that alumina and the carbonates of lime and 

 magnesia may have a minor fixing action on the arsenic. Humus, which was 

 present in abundance in the samples, did not tend to prevent the detection of 

 the arsenic. 



Selective adsorption by soils, E. G. Parker {Jour. Agr. Research, 1 {1913), 

 No. 3, pp. 179-188, figs. 2). — Various theoretical considerations bearing on the 

 adsorptive power of soils are discussed, and several series of experiments in 

 which samples of soil were shaken with solutions of potassium chlorid alone 

 and with sodium nitrate, monocalcium phosphate, and ^ other salts and the 

 amount of the adsorbed bases determined by analysis of the resultant solution 

 are reported. 



These experiments were based "on the assumption that certain ingredients 

 of the soil adsorb in part the base of a neutral salt in solution and that the 

 free acid resulting from the hydrolysis caused by this adsorption reacts with 

 certain of the soil particles and dissolves an almost equivalent amount of bases 

 of the soil." 



