LOCATION HEXT TXEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, active, thermic Typic Haplustepts
TYPICAL PEDON: Hext fine sandy loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 8 inches; brown (7.5YR 5/4) fine sandy loam, dark brown (7.5YR 3/4) moist; weak fine granular structure; hard, friable; many fine roots; common fine pores; few earthworm nests and tunnels; few fine concretions of calcium carbonate with dark coatings; slightly effervescent; moderately alkaline; gradual smooth boundary. (4 to 11 inches thick)
A2--8 to 12 inches; brown (7.5YR 5/4) fine sandy loam, dark brown (7.5YR 4/4) moist; weak fine granular structure; hard, friable; many fine roots; common fine pores; common films and threads of calcium carbonate; slightly effervescent; moderately alkaline; gradual wavy boundary. (0 to 8 inches thick)
Bk--12 to 19 inches; brown (7.5YR 5/4) fine sandy loam, dark brown (7.5YR 4/4) moist; compound weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable; common fine root; common fine pores; 5 percent concretions of calcium carbonate 5 to 15 mm in diameter; common films and threads of calcium carbonate; calcareous; moderately alkaline; abrupt wavy boundary. (4 to 20 inches thick)
BCk--19 to 30 inches; very pale brown (10YR 7/4) fine sandy loam, light yellowish brown (10YR 6/4) moist; massive; compact and hard in the upper part, less compact and slightly hard in the lower part; few fine roots; common fine pores; 20 percent by volume of concretions of calcium carbonate; fine angular fragments of limestone and soft bodies of calcium carbonate; calcareous; moderately alkaline; clear wavy boundary. (0 to 20 inches thick)
Cr--30 to 50 inches; stratified pale yellow (2.5Y 7/4) weakly consolidated sandstone and weakly cemented sand marl; massive; slightly hard; calcareous; moderately alkaline.
TYPE LOCATION: Menard County, Texas; about 19 miles southeast of Menard, Texas, 200 feet east of the Saline Schoolhouse and on the north side of a county road, 0.25 mile east of the Farm Road 1221, in the roadcut.
RANGE IN CHARACTERISTICS: Depth of the soil to a paralithic contact with weakly consolidated sandstone, siltstone, lime cemented conglomerate or cemented sandy marine marl ranges from 20 to 40 inches. The soil is slightly or moderately alkaline. Calcium carbonate equivalent in the control section ranges from 8 to 40 percent.
The A horizons have hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 to 4. Horizons with moist values and chroma of less than 3.5 have less than 1 percent organic matter. Texture is fine sandy loam or loam.
The Bk horizon has hue of 5YR to 10YR, value of 5 to 7, and chroma of 2 to 4. The Bk horizon is fine sandy loam, loam, or sandy clay loam. Total clay content ranges from 10 to about 25 percent. Silicate clay content ranges from 8 to 18 percent. In some pedons the Bk horizon extends to the paralithic contact.
The BCk, is fine sandy loam, loam, or sandy clay loam. The upper 1 or 2 inches of the horizon is weakly to strongly cemented in some pedons.
The Cr horizon ranges from weakly consolidated sandstone or siltstone to strongly cemented calcareous sandstone conglomerate or sandy marl.
COMPETING SERIES: These are the Hardeman series. Similar soils are the Brackett, Enterprise, Shep, and Weymouth series. Hardeman soils do not have bedrock within 40 meters. Brackett soils have fine-loamy control sections and have carbonatic mineralogy. Enterprise soils have coarse-silty control sections. Shep and Weymouth soils have fine-loamy control sections.
GEOGRAPHIC SETTING: Hext soils are on gently sloping to sloping upland ridges and knolls. Slope gradients are dominantly 1 to 5 percent, but range from 1 to 20 percent. The soil formed in alkaline loamy earths and weakly cemented calcareous sandstones of Lower Cretaceous Age. Mean annual precipitation ranges from 24 to 30 inches and mean annual temperature ranges from 63 to to 70 degrees F. Thornthwaite annual P-E index ranges from 38 to 44. Frost free days range from 210 to 240 days and elevation ranges from 1500 to 2350 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blanket, Brackett, Cisco, Menard, and Tarrant series. Blanket, Cisco, and Menard soils have argillic horizons and more than 18 percent clay in the control section. Tarrant soils are clayey, have a mollic epipedon, and limestone bedrock at depths of less than 20 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low to medium; Permeability is moderate.
USE AND VEGETATION: Mostly cultivated, with some areas being used for rangeland or pasture. Crops are mostly small grains grown for grazing and sorghums grown for hay. Native vegetation is little bluestem, indiangrass, sideoats grama, sand lovegrass, and Texas wintergrass. Woody vegetation includes agarita, condalia, Texas persimmon, juniper, and scrubby live oak.
DISTRIBUTION AND EXTENT: Central Texas, mainly in small areas along the margins of the Edwards Plateau or Grand Prairie. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Menard County, Texas; 1965.
REMARKS: Diagnostic horizon and features recognized in this pedon are:
Ochric epipedon - 0 to 12 inches (A horizons)
Calcic horizon - 12 to 30 inches (BCk horizon)