518 EXPERIMENT STATION KECORD. 



to an average depth of about 20 in., where the gray or whitish chalk or rotten 

 limestone is usually encountered. . . . The drainage of the type is usually 

 fairly well established, although upon the more level areas the internal drainage 

 of the subsoil may be defective. Erosion is one of the principal difficulties 

 experienced in the occupation of this land, and slopes in excess of 10° should 

 be covered with grass for pasturage purix)ses." This soil type is stated to 

 constitute one of the best alfalfa soils in the upland portion of the Gulf States. 

 It is also an important cotton soil, and fairly well adapted to the production 

 of corn, oats, and hay. 



Circular 50.— The Houston black clay, of which a total of 1.402,392 acres in 

 15 different areas in 3 States has been surveyed and mapped. This soil type is 

 stated to be probably the best and most productive of the extensive upland 

 cotton soils of the Southern States. It is also an excellent corn soil and fairly 

 well adapted to wheat, oats, and hay. " More recently alfalfa has been grown 

 upon the Houston black clay and the better drained areas of the type are well 

 suited to this crop." 



Circular 51. — The Susquehanna fine sandy loam, of which a total of 1,686,528 

 acres in 27 different areas in 5 States has been surveyed and mapped. This 

 soil type is stated to occur to a considerable extent in Alabama and adjoining 

 States, but chiefly in northern Louisiana and eastern Texas. It occupies roll- 

 ing to hilly areas, and is subject to severe erosion. Cotton and corn are the 

 principal crops grown on it. Its improvement requires protection from erosion, 

 deeper plowing, and incorporation of organic matter. 



Clay County soils, C. G. Hopkins et al. {Illinois Sta. Soil Rpt. 1, pp. 32, 

 pis. 2, figs. 2). — This is the first of a series of Illinois County soil reports and 

 deals with a county which is representative of the common clay soils of south- 

 ern Illinois. It is the purpose to make these reports so complete for each 

 county that "a study of the soil map and the tabular statements concerning 

 crop requirements, the plant food content of the different soil types, and the 

 actual results secured from definite field trials with different methods or sys- 

 tems of soil improvement, and a cai'eful study of the discussion of general 

 principles and of the descriptions of individual soil types " which are given in 

 each report " will furnish the most necessary and useful information for the 

 practical improvement and permanent preservation of the productive power of 

 every kind of soil on every farm in the county." 



The prevailing soil types of the county are gray silt loam on tight clay (37 

 per cent) and yellow silt loam, but there are smaller areas of a number of 

 other types. It is shown that as a rule the soils of Clay County are deficient 

 in nitrogen and phosphoric acid but abundantly supplied with potash. A sys- 

 tem of cropping and fertilizing (including use of ground limestone and phos- 

 phates and green manures) to correct this condition is described. 



Moultrie County soils, C. G. Hopkins et al. {Illinois Sta. Soil Rpt. 2. pp. 

 40, pi. 1, figs. 8). — This is the second of a series of Illinois County soil reports, 

 and gives the results of a soil survey with a soil map of Moultrie County, which 

 is representative of the prairie lands of the corn belt. The soil formation and 

 types of the region are described, and estimates, from chemical analyses, of the 

 plant food content per acre of the soils are given, with a compilation of data 

 on fertilizer requirements as determined by experiments on similar soil types 

 in other parts of the State. 



" The most significant fact revealed by the investigation of Moultrie County 

 soils is the low phosphorus content of the common brown silt loam prairie, a 

 type of soil which covers more than three-fourths of the entire county. The 

 market value of this land is about $200 an acre, and yet an application of $30 

 worth of fine-ground raw rock phosphate would double the phosphorus content 



