SOILS FERTIIJZEES. 317 



It is stated that drainage is the most iniiHirtaut of all forms of soil im- 

 provement uix)n the soils of this series. 



The Miami series of soils, J. A. Bonsteel {U. 8. Dept. Agr. Bui. 1^2 (1914), 

 pp. 59, pis. 13, fig. 1). — This bulletin deals with the distribution, crop adapta- 

 tions, cultivation, and fertility requirements of a series of soils of glacial origin 

 which occur most extensively in western Ohio, central and northeastern Indi- 

 ana, southern Michigan, the Traverse Bay region of Michigan, extreme north- 

 eastern Illinois, eastern Wisconsin, and a portion of the upper peninsula of 

 Michigan. These soils are distinguished by prevailing brown, light brown, or 

 gray surface soils and yellowish-brown or darker brown subsoils. 



" By far the greater part of the area occupied by the important types of the 

 series is gently undulating to moderately rolling. The natural drainage over a 

 large part of the territory is fair to good. . . . The Miami flne sandy loam, 

 loam, silt loam, and clay loam comprise by far the greatest area of the soils 

 of this series, and they are well suited with respect to topography, drainage 

 and moisture conditions, and climatic surroundings to the growing of the most 

 important staple crops of the temperate region. The more gravelly and sandy 

 soils of the series are relatively unimportant agriculturally. . . . While crop 

 yields are, in general, satisfactory, it has been found that careful attention to 

 crop rotation, the iucorix>ration of organic manures, the use of commercial 

 fertilizers with the small grain crops, liming, and tile underdrainage on the 

 heavier types aid in increasing crop yields." 



Soil survey of Jeff Davis County, Georg'ia, P. O. Wood et al. {U. S. Dept. 

 Agr., Advance Sheds Field Operations Bur. Soils, 1913, pp. 34, fig. 1, map 1). — 

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

 was issued November 21, 1914. It deals with an area of 208,000 acres in south- 

 eastern Georgia, the topography of which varies from flat to rolling. The county 

 is drained by the Ocmulgee and Altamaha rivers and by numerous creeks which 

 eventually flow into the Satilla Eiver. Many fields and some entire farms are 

 said to be greatly in need of drainage. 



In general the soils of the county consist of sands of varying texture under- 

 lain usually at comparatively shallow depths by sandy clays. Twenty-two soil 

 types of twelve series are mapped, of which the Norfolk and Tifton are the 

 most important both in extent and agricultural value. Crop rotation is practiced 

 only in a limited way but the appreciation of its importance and of the need of 

 humus in the soil and of adequate drainage is growing. The use of commercial 

 fertilizers is universal and it is stated that most of the soils need lime. 



Soil survey of Bremer County, Iowa, M. Baxwin, E. B. Watson, and F. B. 

 Howe (U. S. Dept. Agr., Adva^icc Sheets Field Operations Bur. Soils, 1913, pp. 

 37, fig. 1, map 1). — This survey, made in cooperation with the Iowa Agricul- 

 tural Experiment Station, was issued November 21, 1914. It deals with an area 

 of 277,760 acres in northeastern Iowa, the topography of which as a whole is 

 gently undulating to rolling. The regional drainage is good. 



The soils of the county fall into four general classes, namely, those composed 

 of glacial drift of the Iowa glaciation, the reworked soils originating from the 

 glacial drift, the residual limestone soils, and the silty and sandy soils. Twenty- 

 one soil tyi^es of eleven series are maiJi>ed, of which the Carrington loam is the 

 most important and covers 62.8 per cent of the total area. No systematic rota- 

 tion of crops as a rule is followed in the county and commercial fertilizers are 

 said to be unimportant in the agricultural practice. The importance of careful 

 conservation and application of organic manures is, however, being more and 

 more recognized. 



The influence of g'laciation on agriculture in Ohio, E. W. Owen {Bui. Sci. 

 Lahs. Dcnison Univ., 11 (1914), Art. 11-14, pp. 390-394, fig- i).— An investiga- 



