Land use: Most of this area is range grazed by beef cattle and wildlife. Grain sorghum, cotton, and small grain for grazing are the main crops. Local areas are irrigated. Hunting leases for deer, wild turkey, quail, mourning dove, javelina, and exotic game animals are an important source of income. The major concern of management is controlling brush and cactus that invade the grasslands.

Elevation and topography: Elevation ranges from 25 m in the east to 200 in m the northwest. This plain is nearly level to gently undulating and is weakly dissected by intermittent drainageways.

Climate: Average annual precipitation-525 to 650 mm. Maximum precipitation is during the growing season. Average annual temperature-21 to 23 C. Average freeze-free period-280 to 325 days.

Water: Rainfall is adequate for the growth of range grasses, but crop yields are limited by periods of moisture stress caused by high temperatures and high evaporation and transpiration rates. Deep wells and ponds provide water for irrigation, livestock, and domestic use.

Soils: Most of the soils are Ustalfs. They are moderately deep to deep and moderately coarse textured and coarse textured and have mixed mineralogy. Ustolls are also extensive. These soils have a hyperthermic temperature regime and an ustic moisture regime. Gently undulating Paleustalfs (Nueces and Sarita series) are on sandy eolian plains. Nearly level to gently sloping Paleustalfs (Delfina and Delmita series) are on loamy eolian plains in the central and eastern parts of the area. Nearly level to gently undulating Haplustalfs (Brennan and Comitas series) are on loamy eolian plains in the central and western parts. Gently sloping to gently undulating Calciustolls (Hidalgo and Olmos series) and Haplustolls (Tordia series) are on plains underlain by ancient marine sediments. Nearly level to gently undulating Orthids (Copita, Randado, and Zapata series) are on plains in the western part of the area.

Potential natural vegetation: This area supports prairie vegetation with a few scattered trees and shrubs. Major species on soils with deep, fine sand surfaces are tall and mid grasses such as seacoast bluestem, indiangrass, crinkleawn, and tanglehead and an abundant variety of perennial legumes and forbs. Species commonly growing on soils on loamy eolian plains in the central and eastern parts of the area are mid grasses such as Arizona cottontop, fourflower thichloris, tanglehead, plains lovegrass, and pinhole bluestem. Many forbs and low-growing shrubs, including condalias, vine ephedra, and guajillo, grow with these grasses.

(From "Land Resource Regions and Major Land Resource Areas of the United States". United States Department of Agriculture Soil Conservation Service Handbook 296. Dec. 1981. page 58.)