422 EXPERIMENT STATION RECORD. [Vol.35 



Winnebago County is located in northern Illinois in the lowan and pre-Iowan 

 glaciations and is covered with a deposit of drift, loess, and alluvial material. 

 The soils of the county are divided as follows: (1) Upland prairie soils, rich in 

 organic matter. These were covered originally with prairie grasses, the par- 

 tially decayed roots of which have been the source of the organic matter; (2) 

 upland timber soils, including practically all of the upland that was formerly 

 covered with forests; (3) residual soils, including stony loam and rock outcrop; 

 (4) terrace soils, which include bench lands or .second bottom lands; (5) late 

 swamp and bottom land soils, which include the overflow lands or present flood 

 plains along the streams and other poorly drained lands." Of these the brown 

 silt loam and brown sandy loam of the upland prairie soils cover 21.35 and 19.1 

 per cent of the area, respectively, while the yellow-gray silt loam upland timber 

 soil covers 16.13 per cent. " The most significant facts revealed by the investiga- 

 tion of the AVinnebago County soils are the lack of limestone and the low con- 

 tent of phosphorus, or nitrogen, or both, in the most common prairie and timber 

 types." 



Soil survey of Webster County, Iowa, J. O. Veatch and F. B. Howe (C7. S. 

 Dept. Ayr., Advance Sheets Field Operations Bur. Soils, 1914, PP- M, fiO- 1, 

 map 1). — This survey, made in cooperation with the Iowa Experiment Station 

 and issued June 1, 1916, deals with the soils of an area of 456,960 acres in 

 central Iowa, the topography of which is level to very gently undulating without 

 marked relief. A large part of the area is imperfectly drained. " The county 

 lies in that part of the State covered by the last great ice invasion of the 

 Pleistocene period." 



The soils are mainly of glacial origin and are prevailingly black. Including 

 peat and muck, eleven soil types of six series are mapped, of which the Fargo 

 loam, Carrington loam, and Fargo clay loam cover 46.6, 23, and 22.1 per cent of 

 the area,, respectively. 



Soil survey of Jefferson Davis County, Mississippi, T. M. Bushnell and 

 L. V. Davis (C7. S. Dept. Agr., Advance Sheets Field Operations Bur. Soils, 

 1915, pp. 27, fig. 1, map 1). — This survey, made in cooperation with the State 

 of Mississippi and issued June 8, 1916, deals with the soils of an area of 259,840 

 acres in southern Mississippi lying entirely within the Coastal Plain. " The 

 topography is prevailingly rolling but seldom too steep for cultivation. Drain- 

 age is well established." The upland soils comprise 84 per cent of the area. 

 Fifteen soil types of nine series are mapped, of which the Ruston fine sandy 

 loam covers 52.3 per cent of the area. 



Soil survey of Pettis County, Missouri, H. H. Krusekopf and R. F. Rogeks 

 (C7. S. Dept. Agr., Advance Sheets Field Operations Bur. Soils, lOlJf, pp. ^1, 

 fig. 1, map 1). — This survey, made in cooperation with the Missouri Experi- 

 ment Station and issued June 6, 1916, deals with the soils of an area of 432,000 

 acres in west-central Missouri. " In general, the topography is smooth to gently 

 rolling, with rough areas in the limestone region in the northeastern part of 

 the county." 



The soils of the county are " silt loams, containing relatively little sand or clay. 

 They are usually mellow or are easily made so with proper treatment. They 

 are well drained and are moderately early and warm. The subsoils are uni- 

 versally heavier than the surface material which makes the various types 

 generally retentive of moisture. As in most prairie regions, the soils originally 

 had a high content of organic matter, but continuous cropping has reduced this 

 to a large extent." Including rough stony land, 22 soil types of 14 series are 

 mapped, of wliich the Oswego and Summit silt loams cover 24.9 and 20.8 per 

 cent of the area respectively. 



