6 SOILS OF THE EASTERN UNITED STATES. 



northern areas of the type, and it is desirable to raise alfalfa upon at 

 least some portion of the farm acreage in addition to the crops men- 

 tioned, which may be arranged in regular rotation. Alfalfa thrives 

 upon the well-drained areas of the type and should be more exten- 

 sively grown. 



In the western and southwestern areas it is found desirable to 

 produce more drought-resistant crops than are planted in the locali- 

 ties where rainfall is more abundant. For these former locations 

 sorghum, millet, kafir, and alfalfa are ah 1 available, either in conjunc- 

 tion with cotton or in areas where the latter crop is not extensively 

 produced. 



For the improvement of the efficiency of the Houston black clay 

 it is also desirable that greater attention should be paid to the internal 

 drainage of the subsoil. While the greater portion of the type is 

 well drained, so far as the surface flow of water is concerned, the stiff, 

 waxy claylike nature of both surface soil and subsoil tends to store 

 a large amount of excess moisture in the subsoil and also to render 

 the surface soil plastic and sticky until late in the spring planting 

 season. Tile underdrainage to promote the downward percolation 

 and removal of water absorbed by the soil should be installed over 

 many thousands of acres of this type. Such an improvement, while 

 of considerable initial cost, is usually amply repaid through the fact 

 that the land may be tilled at an earlier date, that it may be culti- 

 vated more immediately after a rainfall, and that the available water 

 supply of both surface soil and subsoil throughout the growing season 

 is more easily obtained by the growing crops. Tile underdrainage is 

 essential for the production of alf alf a on all of those areas of the type 

 whose surfaces are practically flat. 



To the present time nearly all areas of the Houston black clay 

 have been tilled regardless of the fertilization of the soil, either 

 through the restoration of organic matter to the surface soil or the 

 application of mineral commercial fertilizers. While either class of 

 fertilization is possibly less needed upon the Houston black clay than 

 upon the majority of other southern soils, still the structure of this 

 waxy clay may be greatly unproved by the incorporation of organic 

 matter as frequently as may be possible in the crop rotation. The 

 fibrous nature of the green crop plowed under aids in the granulation 

 and the improvement of the texture of the surface soil. In this con- 

 nection lime should be applied at the time when the green crop is 

 plowed under, hi order to promote its decomposition and incorpora- 

 tion with the soil. 



So little has been done in the line of the application of commercial 

 fertilizers to the Houston black clay that little may be said in regard 

 to the proper use of these materials. Further experimentation 

 should be conducted along this line. 



