Land use: Most of this area is in farms and ranches, but sizable acreages in the central section are rapidly being converted to urban uses. About 80 percent of the rural land is in improved pasture, native grass pasture, or noncommercial oak forest vegetation and is grazed by beef cattle. About 10 percent of the area is farmed to peanuts, small grain, forage sorghums, and fruit and vegetable crops. In general, the acreage of cropland is decreasing, and that of improved pasture and urban development is increasing.
Elevation and topography: Elevation is about 200 m. Extensive gently sloping to rolling uplands are moderately dissected. Sloping to rolling sandstone-capped hills and ridges rise prominently above the surrounding uplands. Stream valleys are narrow and have steep gradients. Local relief is mostly from 1 to 10 or 15 m.
Climate: Average annual precipitation - 875 to 1,000 mm. Maximum precipitation is in spring and in fall. Average precipitation during the frost-free period is about 600 to 650 mm. The summer moisture deficit ranges from about 125 to 200 mm. Average annual temperature - 17 to 19 C. Average freeze-free period - 227 to 250 days.
Water: The moderate and somewhat erratic rainfall is the major source of water for pasture and crops. Large reservoirs provide water for cities and towns and for recreation. Farm ponds are a major source of water for livestock. In most of the area, shallow wells supply water for domestic use. A few small irrigation wells supply a very limited quantity of water. Local streams have intermittent flow.
Soils: Most of the soils are Ustalfs. They are well drained and medium textured and coarse textured. These soils have a thermic temperature regime, an ustic moisture regime, and mixed, siliceous, or montmorillonitic mineralogy. Shallow to moderately deep Haplustalfs (Rayex series) and Paleustalfs (Birome series) are on sandstone-capped hills and ridges. Moderately deep to deep, gently sloping to sloping Paleustalfs (Aubrey, Birome, Callisburg, Crosstell, Gasil, and Konsil series) are on uplands. Deep, gently sloping Paleustalfs (Silstid and Heaton series) and Quartzipsamments (Arenosa series) are on sandy uplands. Haplustolls (Gowen series) and Ustifluvents (Pulexas and Bunyan series) occupy narrow flood plains.
Potential natural vegetation: This area supports oak savanna vegetation with a tall grass understory. Little bluestem, purpletop tridens, indiangrass, switchgrass, big bluestem, post oak, blackjack oak, elm, coralberry, American beautyberry, bumelia, greenbrier, and elbowbush are some of the dominant species. Engelmann-daisy, lespedezas, and trailing wildbeans are among the numerous perennial forbs.
(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 61.)