148 SCIENCE AND SOIL 



stiff loam or light clay loam, -which becomes a more pronounced red in depth. 

 Traces of chert are found in both soil and subsoil. This type was formed by 

 the slow weathering of limestones. In this soil the weathering has been so 

 complete and the leaching so excessive that the lime of the disintegrated stone 

 has been largely washed from the soil. The type has a moderately rolling sur- 

 face, and has good surface drainage, but the subsoil is rather impervious. The 

 underlying limestone comes near the surface in some places, owing to erosion. " 



(1050 Ib. P.) "The Hagerstown loam is all used in the extensive system 

 of general farming which is practiced throughout the area. Corn yields from 

 15 to 30 bushels, with a probable average of 22 bushels per acre. Wheat 

 yields from 5 to 20 bushels, with an average of 10 bushels, and the compara- 

 tively small amount of hay which is grown yields an average crop of i ton per 

 acre." (Report for 1903, page 584.) 



Houston clay (Alabama) "has resulted from the weathering of rotten 

 limestones or chalks of Cretaceous time. Owing to its proximity to the soft 

 and easily broken down lime rock, this soil is highly calcareous, and often 

 contains lime concretions, especially in the subsoil. It may be considered to 

 be of comparatively recent origin .and as a residual Coastal Plains soil. The 

 soil is a gray, brown, or black loamy clay, 6 inches deep. This is underlain 

 with 3 feet or more of heavy gray or mottled yellow clay. The surface is gently 

 rolling and the drainage very good. Agriculturally, the soil is lighter than 

 would be expected, from its high clay content. This may be due to floccula- 

 tion by the high percentage of lime present. " 



(5150 Ib. P.) "The Houston clay, while clodding badly when plowed too 

 wet, and requiring care in its management, is a very strong and productive 

 soil." (Report for 1905, page 464.) 



Cecil clay (North Carolina) "is found on uplands, gentle slopes, and roll- 

 ing lands of the Piedmont Plateau. The Cecil clay is a residual soil, result- 

 ing from the disintegration of a number of rocks, differing in mineralogical 

 characters. Granites, gneisses, schists, and other somewhat similar rocks have 

 contributed to the formation of this type, and so thorough have been the dis- 

 integration and decomposition that the same red clay results from all. There 

 is such a gradual change from soil to the parent rock that there is generally no 

 sharp line between the two. The soil consists of a heavy red loam, contain- 

 ing many sand grains of the original minerals forming the rocks from which the 

 soil is derived. It is shallow, averaging about 5 inches. The subsoil is a 

 stiff, tenacious red clay to a depth of 3 or more feet. It becomes heavier 

 at greater depths. Natural drainage is fairly good, probably due to the sand 

 and rock fragments contained in soil and subsoil." 



(960 Ib. P.) "The soil is generally thin, but can be deepened by proper 

 methods of cultivation and by green manuring. When so deepened, it assumes 

 the properties of a heavy clay loam, and is very productive. It requires, 

 however, considerable care and labor to maintain its fertility." (Report for 

 1901, page 55.) 



