THE TRINITY CLAY. 11 



or more a ton. In consequence, areas of the Trinity clay properly 

 situated with regard to overflow and drainage are extremely valuable 

 for alfalfa production, and the acreage of the crop should be con- 

 siderably increased. 



Practically the only other crops grown upon the Trinity clay are 

 limited acreages of rice in the Texas Gulf coast region, and a small 

 amount of sugar cane in the extreme southern portion of the same 

 section. Rice production should probably be extended upon some 

 other type than the Trinity clay, but where the climatic conditions 

 are favorable the type is admirably suited to the production of large 

 yields of sugar cane and the growing of the crop might be consid- 

 ably extended with profit to the grower. 



FARM EQUIPMENT. 



The farm equipment of the Trinity clay is usually that of the 

 adjoining uplands, since portions of the type are tilled in connection 

 with larger areas of upland soils. In fact, very few farm buildings 

 are erected upon the type owing to its liability to overflow. In gen- 

 eral, the light one-mule rig used on the more sandy upland soils is 

 also employed for the breaking and tillage of the Trinity clay. This 

 lightweight outfit is totally inadequate for the proper management 

 of such a heavy, tenacious, plastic soil. In fact, unless the moisture 

 conditions are decidedly favorable it is extremely difficult to break 

 or turn the surface soil with a moldboard plow, and the use of the 

 disk plow and disk cultivator should become much more general upon 

 areas of the Trinity clay. Then if the soil is tilled under favorable 

 moisture conditions the disk machinery is capable of inducing a 

 thoroughly granulated and mellow surface condition, highly favor- 

 able to the retention of moisture and to the satisfactory growth of 

 the crop. Where such machinery has been used increased crop yields 

 have not infrequently resulted, and some of the best planters have 

 secured such machinery for use upon the type after experiencing 

 the benefits to be derived from its use upon the upland black prairie 

 soils, w r hich are similar in many respects to the Trinity clay and 

 from which the materials composing the latter type have been 

 derived. 



SUMMARY. 



The Trinity clay is a black, tenacious, heavy clay found in the 

 alluvial bottom lands of the main streams which flow through the 

 black Cretaceous prairies of Alabama. Mississippi, and Texas and 

 to a considerable distance along the lower courses of such streams 

 as have their headwaters in the prairie sections. Both the surface 

 soil and subsoil are unusually heavy and plastic. The subsoil is 

 marked by a considerable content of calcium carbonate. The sur- 



