1917] SOILS — FERTILIZERS. 115 



" The soils of the county are of marine sedimentary origin and are predomi- 

 nantly sandy. There are two general groups, the light-colored, well-drained 

 soils and the poorly drained, or dark-colored, soils." 



Including shell mounds, muck, coastal beach, tidal marsh, and swamp, 13 

 soil types of 6 series are mapped, of which the Hyde fine sand, the Plununer fine 

 sand, and swamp cover, respectively, 34.3, 22.6, and 10.9 per cent of the area. 



Soil survey of Jewell County, Kansas, L. E. Call, R. I. Throckmorton, 

 C. O. SwANsoN, ET AL. {Kaiisos Sta. Bui. 211 {1916), pp. 36, map 1). — This re- 

 port of a survey made in cooperation with the Bureau of Soils of the U. S. 

 Department of Agriculture deals with the general characteristics and chemical 

 composition of the soils of an area of 578,840 acres in northern Kansas. 



"The soils of Jewell County fall naturally into four general groups: (1) Re- 

 sidual .soils, or those derived from the underlying rocks; (2) loessial soils, or 

 those formed from the weathering of wind-blown deposits; (3) soils of mixed 

 loessial and residual origin; and (4) alluvial soils, or those laid down by 

 streams." Nineteen soil types of 7 series are mapped, of which the Colby silt 

 loam and silty clay loam cover 52.3 and 16.9 per cent, respectively. Average 

 chemical analyses of the different soil types are also reported, which are taken 

 to indicate that the potassium, phosphorus, and lime contents are relatively 

 high, although the phosphorus is more available in the soil than in the subsoil. 

 It is pointed out that the cultivated soils have lost from one-fourth to two-fifths 

 of the nitrogen originally present in the virgin soil. 



Some soils from the Kuala Pilah and Jelebu districts, J. Grantham {Agr. 

 Bvl. Fed. Malay .States, J, {1916), No. 8, pp. 2^-2//?).— Mechanical and chemical 

 analyses of five samples of padi soils, three samples of rubber soils, two sam- 

 ples of jungle soils, and one sample of white soil are reported and discussed. 



Critical contribution on the origin of the Mediterranean red soils, E. 

 Blanck {Lamlw. Vers. Stat.. 87 {1915), No. //-5, pp. 251-314).— This is a critical 

 review and analysis of work bearing on the subject conducted by the author 

 and others. 



The results are taken to indicate that generally, where the presence of dolo- 

 mite has caused the absence of humus, conditions are favorable to the forma- 

 tion of red soil, depending on the action of climatic factors which partially or 

 wholly prevent humus accumulation. The part played in the formation of red 

 soil by insoluble residues of limestone origin is considered of minor impor- 

 tance, since such residue forms only a small part of the red soil and can not 

 account for iron accumulations. The latter are attributed to the metasomatic 

 displacement of lime and to the powers of diffusion of iron solutions added 

 from without. 



Humification of compounds contained in vegetable organic matter, A. 

 TRUsov (Trussoff) {Sclsk. Khoz. i Ltesov., 250 {1916), Mar., pp. 339-361).— 

 Experiments, especially with dry maple leaves, to determine the amount of 

 humus formed during the decomposition of vegetable residues in surface soil 

 are reported. 



It was found that the content of water-soluble humus in decomposing 

 organic matter varied, amounting to 1.93 per cent in maple leaves gathered 

 soon after their fall. The plant residues contributed more actively to humus 

 formation and the content of humus soluble in ammonia was larger during 

 the earlier stages of decomposition. The relations between the amounts of 

 humus soluble in water and in ammonia varied with different vegetable mate- 

 rials and periods of decomposition. Frequent drying of the leaves during 

 decomposition decreased the humus content. During decomposition there was 

 no increase in humus content after eight days, and after 156 days no water- 

 soluble humus was found. 



