* Vertisols: These are clay-rich soils that shrink and swell significantly with changes in moisture content. This makes them prone to cracking during dry periods and becoming very sticky and difficult to work with when wet. Vertisols are known for their fertility and are well-suited for certain crops, especially cotton.
* Aridisols: These soils are found in arid and semi-arid regions, like the South Texas Plains. They are characterized by low organic matter content and a lack of moisture. Aridisols can be further subdivided into different subtypes, depending on their specific characteristics.
* Mollisols: These soils are found in grasslands and are rich in organic matter. They are generally fertile and well-suited for agriculture. Mollisols are found in certain areas of the South Texas Plains, particularly in the eastern portions where rainfall is slightly higher.
* Alfisols: These soils are found in areas with moderate rainfall and are characterized by a moderate amount of organic matter and a well-developed soil profile. Alfisols are also found in some parts of the South Texas Plains.
In summary: The South Texas Plains have a diverse range of soils, but Vertisols are the most prominent type. The specific soil type found in a given area will depend on factors such as elevation, rainfall, and vegetation.
