420 EXPERIMENT STATION RECOBD. [Vol. 36 



facts. Examples of these computations have been shown with considerable and 

 seemingly all necessary fullness." 



A bibliography of the more recent literature on this subject is given. 



SOILS— FERTILIZEES. 



Soil survey of the Ukiah area, California, E. B. Watson and R. L. Pendle- 

 ton (U. S. Dept. Agr., Advance Sheets Field Operations Bur. Soils, 1914, PP- 53, 

 pis. 5, figs. 2, map 1). — This survey, made in cooperation with the California 

 Experiment Station, and issued December 16, 1916, deals with the soils of an 

 area of 193,920 acres in southeastern Mendocino County, Cal., which includes 

 several arable valleys and a part of the Coast Range Mountains. The drainage 

 of the hills is well established, and that of the valley floors, with some few ex- 

 ceptions, is generally complete. 



" The soils of the Ukiah area fall into three general groups [as follows] : 

 (1) Residual soils, (2) soils derived from old valley-filling material, and (3) 

 soils derived from recent alluvial deposits." Including rough mountainous land 

 and river wash, 20 soil types of ten series are mapped, of which rough mountain- 

 ous land covers 67.7 per cent and Pinole gravelly loam 11.4 per cent of the area. 



Soil survey of Washington County, Georgia, R. A. Winston, J. H. Agee, 

 J. A. Kekr, and M. E. Cark {U. S. Dept. Agr., Advance Sheets Field Operatiotis 

 Bur. Soils, 1915, pp. 39, fig. 1, map i).— This survey, made in cooperation with 

 the Georgia State College of Agriculture, and issued December 1.5, 1916, deals 

 with the soils of an area of 428,160 acres in the Coastal Plain region of east 

 central Georgia, the topography of which ranges from undulating to rolling. 

 The uplands are naturally well-drained, while the first bottom lands are usually 

 low, flat, and poorly drained. 



The soils are of sedimentary origin and range from loose incoherent sands 

 to fairly heavy silty clays. Including meadow, 20 soil types of 10 sei'ies are 

 mapped, of which the Norfolk sandy loam, Orangeburg sandy loam, Norfolk 

 sand, meadow, and Ruston sandy loam cover 21.4, 17.7, 13.5, 11.1, and 10.2 per 

 cent of the area, respectively. 



Soil survey of Wilkes County, Georgia, D. D. Long {U. S. Dept. Agr., Ad- 

 vance Sheets Field Operations Bur. Soils, 1915, pp. 35, fig. 1, map 1). — This 

 survey, made in cooperation with the Georgia State College of Agriculture, and 

 issued December 18, 1916, deals with the soils of a well-drained area of 306,.380 

 acres in the Piedmont plateau province in northeastern Georgia. The topog- 

 raphy in general is gently rolling. 



Most of the soils of the county are of residual origin and are heavy, belonging 

 to the silty clay loam, clay loam, and clay classes. A considerable area of 

 soils of sandy loam, fine sandy loam, and loam texture also occurs. Including 

 meadow, 18 soil types of five series are mapped, of which the Cecil clay loam 

 and sandy loam cover 38.5 and 18.5 per cent of the area, respectively. 



Soil survey of Coahoma County, Mississippi, F, Z. Hutton et al. (C7. iS?. 

 Dept. Agr., Advance Sheets Field Operations Bur. Soils, 1915, pp. 29, fig. 1, 

 map 1). — This survey, made in cooperation with the State of Mississippi and 

 issued December 19, 1916, deals with the soils of an area of 357,120 acres in 

 the Mississippi Delta region in northwestern Mississippi. In spite of the nu- 

 merous streams, large areas in the county have poor drainage. 



The soils consist entirely of alluvial deposits, and the more important are 

 divided into two groups, (1) having heavy clay subsoils, and (2) having light- 

 textured subsoils. Including meadow, overwasli, and excavated land, 12 .'^oil 

 types of three series are mapped, of which the Sharkey clay, Sharkey silty clay 



