THE HOUSTON CLAY. 7 



in spite of seasonal variations due to climatic conditions. It is 

 believed, however, that this constant cultivation of a single crop has 

 materially reduced the yields over a considerable portion of the type. 

 This in part is probably due to the promotion of excessive erosion 

 and partly to unfavorable physical conditions induced by unvaried 

 cultivation. In contrast, upon limited areas where a crop rotation 

 has been adopted, yields of three-fourths of a bale to one bale of 

 cotton per acre are easily obtained. The general adoption of suitable 

 rotations throughout the area occupied by the Houston clay is there- 

 fore desirable. 



LIMITATIONS UPON SPECIAL CROPS. 



Because of its characteristic texture, the Houston clay is not well 

 suited to the production of any special crops. Moreover, it is usually 

 associated with soils in every area which are well suited to the pro- 

 duction of special crops, and it is, therefore, not advisable to attempt 

 the production of any but the staple crops, including cotton, corn, 

 oats, and hay, upon this type. 



EXTENT OF OCCUPATION. 



In the majority of the more eastern areas where the Houston clay is 

 found, from 60 to 80 per cent of the type is occupied agriculturally. 

 Probably one-half of the total area of the type thus far mapped is 

 annually cropped. An additional one-fourth is used for pasturage 

 purposes. The remaining 25 per cent, consisting chiefly of steep 

 slopes and isolated patches of small size, remains unoccupied. Upon 

 such areas a small amount of timber, principally cedar, is to be found. 

 In the more western areas, under semiarid conditions not more than 

 10 to 15 per cent of the type is annually tilled, and the remainder 

 supports wild grasses, which are cut for hay or grazed off. Wherever 

 the type is found under suitable climatic conditions, it is considered 

 desirable for farming purposes, and while there is a wide range in the 

 selling price of different areas, dependent largely upon the surface 

 configuration of the type and its location with regard to transporta- 

 tion facilities, yet all areas which are reasonably level and fairly 

 near to railroad transportation are highly esteemed. Tracts so situ- 

 ated command prices ranging from $30 to $75 per acre. 



CROP ADAPTATIONS. 



The Houston clay is one of the important Upland cotton soils of ' 

 the Gulf region. Portions of the type have produced cotton almost 

 continuously for periods ranging from 25 to 75 years, maintaining a 

 high average yield during the entire time. In spite of a tendency 



