812 EXPERIMENT STATION EECOED. 



The topographic regions of the State are discussed with reference to their 

 extent, soil characteristics, vegetation, state of cultivation and crops raised, 

 and water supply. 



Bibliography of Tennessee geology, soils, drainage, forestry, etc., 

 Elizabeth Cockrill {Tcnn. Geol. Surrey Bui. 1, Extract B, 1911, pp. 119). — 

 This contains a list, with subject index, of the available reports and papers 

 published on the geology, soils, drainage, and forestry of Tennessee, also a list 

 of publications of the State Geological Survey. 



Reconnoissance soil survey of part of northwestern Wisconsin, S. Weid- 

 MAN, E. B. Hall, and F. L. Musback (Wis. Geol. and Nat. Hist. Survey Bui. 

 23, 1911, Econ. Ser. 14, pp. vni-\-102, pis. IJ^, figs. 16, map i).— The results of a 

 survey of the geological formations, combined with a study of the soils and the 

 climatic and agricultural conditions of the region, including Eau Claire, Chip- 

 pewa, Rusk, Barron, Dunn, Pepin, Pierce, St. Croix, and Polk coimties, and 

 covering an area of 6,705 square miles, are reported. 



The region is well watered. The soils are classed on the basis of texture 

 into 14 types which are mapped and described with respect to area, surface 

 features, forest growth, general character and origin, crop adaptation, and 

 value. They include the Baldwin loams, Colby silt loam, Keunan silt loam, 

 Chelsea loams, Milltown loam, Thornapple sandy loam, Gushing loams, Rice 

 Lake loam, Chetek sandy loam, Meridean sandy loam. Sterling sand, Hartland 

 silt loam, Auburn loam, and peat and muck. Mechanical analyses of each type 

 of soil were furnished by the Bureau of Soils of this Department. 



An appendix on the correlation of the soils of the region with those of north- 

 central Wisconsin (E. S. R., 16. p. 27) is added. 



Black soils (chernozem), P. Kossovich (Internat. Mitt. Bodenk.. 1 {1912), 

 No. 3-Jf, pp. 199-35-'i, figs. 20). — The author gives a complete characterization, 

 based on his own investigations and a study of the literature, of the black or 

 chernozem soils of Russia, including their origin and history, distribution, topo- 

 graphic features, vegetation, climatic conditions, and physical and chemical 

 properties. 



It is stated that the chernozem territoiy covers almost the entire southern 

 half of European Russia, besides isolated areas in western and eastern Siberia. 

 It is an undulating plain, with occasional extensive elevations and ravines. In 

 it are distinguished 3 climatic zones, the northern, central, and southern. 

 In the central zone the typical chernozem soil predominates, whereas along the 

 boundary of the north zone the soil is somewhat modified in that it merges into 

 the gray forest soil of upper Russia. Aloug the southern boundary the cher- 

 nozem merges into the chestnut soils of the dry steppes. 



In virgin steppes, the chernozem is usually covered with a layer of vegetable 

 debris and mineral matter from 2 to 4 cm. in thickness. The surface soil is uni- 

 formly dark in color and has a more or less granular appearance. As the soil 

 merges into the subsoil, the color becomes irregular. The surface zone, called 

 zone A in the Russian terminology, usually extends to a depth of 60 cm. and is 

 the resultant of many genetic factors. Below this depth, called zone B, the 

 character of the soil is determined largely by the parent rock. It is coarser in 

 structure and the size of the granules increases in it as it also does with the 

 clay content of the soil. In very sandy soils the granular structure may be 

 entirely absent. 



The depth of the humus layer of the soil in general varies from 70 to 100 cm. 

 It appears that the depth of soil decreases from west to east and from the 

 center of the chernozem region to the northern and to the southern boundaries. 

 It has also been observed that with few exceptions the depth of the humus layer 

 is greatest for the soils derived from the coarse-grained rocks, which is ex- 



