GEM:KAL SLKVEY or TEXAS WOODLAND*, y 



tility and on the improvement aud future usefulness of the entire land 

 area of our nation. As we learn inure about the real nature of our 

 soils we will know definitely how they will "wear,'' how to maintain 

 their fertility, whether certain soils would really in the end be of more 

 value if devoted to other forms of use than crop production, and by 

 which means they would ultimately return a greater profit. 



The soils of the United States are now divided into thirteen great 

 groups or soil provinces, of which five are recognized as occurring in 

 Texas. Nearly one-half of Texas has now been worked over in the 

 process of soil mapping and the soils of most of the State may now be 

 located and classified with some accuracy. The accompanying soil map 

 (see Map 3) is presented to show in a general way the most important 

 soil divisions of the State. Each of the five groups contains a large 

 number of different soils which may be classified roughly into eighteen 

 main divisions. These are briefly grouped and described as follows, the 

 numbers being used to indicate their positions on the accompanying map : 



Rocky Mountain Region Soils: 

 1 Mountainous. 



Southwestern Soils: 



2. Recent wash and inter-mountain deposits; sometimes contain- 



ing alkali, gypsum, or salt. 

 Western Residual Soils: 



3. Plains soil; somewhat sandy to the south and the northeast 



and with clay or clay loam in the north central parts. 



4. Permian Red Beds soils; derived from sandstone and shales; 



sometimes containing gypsum; also some are alluvium. 



5. Soils derived from sandstone and shales and associated with 



coal formations. 



6. Residual limestone soil, frequently rocky and badly eroded. 



7. Soils of the granitic belt, frequently eroded and thin. 

 Gulf Coast Plains Soils: 



8. Western cross timbers sands. 



9. Eastern cross timbers sands. 



10. The Blacklands. 



11. Sands and plastic clays ; sometimes thin ; subsoils plastic. 



12. Deeper sands and clavs; subsoils usually plastic. 



13. East Texas deep sands: subsoil frequently friable. 



14. Southern extension of the sandy soils: subsoil sometimes fri- 



able: depth of sands variable. 



15. Soils of the Gulf coast prairie: drainage poor; soil largely 



clay or underlain by dense day. 



16. Secondary black lands, frequently thin or gravelly. 



17. Soils of the Rio Grande plnin: sometimes light and of recent 



origin. 

 River Bottom Soils: 



18. Alluvial valors. 



