LOCATION SHEP TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Calcic Haplustepts
TYPICAL PEDON: Shep loam--rangeland.
(Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; brown (7.5YR 5/2) loam, dark brown (7.5YR 4/2) moist; weak fine granular structure; slightly hard, friable; slightly sticky; calcareous, moderately alkaline; abrupt smooth boundary. (4 to 15 inches thick)
Bw--8 to 25 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; weak coarse prismatic parting to weak fine granular structure; slightly hard, friable; slightly sticky; common very fine wormcasts; common nodular calcium carbonate concretions; calcareous, moderately alkaline; gradual wavy boundary. (12 to 35 inches thick)
Bk1--25 to 36 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 5/4) moist; massive; slightly hard, friable; few wormcasts; 10 to 15 percent nodular calcium carbonate concretions; common films and threads of calcium carbonate; calcareous, moderately alkaline; diffuse boundary. (10 to 32 inches thick)
Bk2--36 to 80 inches; light reddish brown (5YR 6/4) sandy clay loam, reddish brown (5YR 4/4) moist; massive; slightly hard, friable; 5 to 10 percent calcium carbonate concretions; common coated fragments of quartz and limestone 1/2 to 1-inch diameter; calcareous, moderately alkaline.
TYPE LOCATION: Taylor County, Texas; about 9 miles south of Merkel, from Interstate Highway 20 overpass over Farm Road 126 in Merkel, Texas; 3 miles south-southwest on Farm Road 126; south on unnumbered county road 6.1 miles and 250 feet east of road in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Calcium carbonate equivalent in the 10 to 40 inch control section is 15 to 40 percent. Siliceous and limestone pebbles comprise 0 to 15 percent of any horizon.
The A horizon has a hue of 5YR through 10YR, value of 4 through 6, and chroma of 2 through 4. Moist values and chromas are less than 3.5, the horizon is less than 10 inches thick. It is loam, sandy clay loam, fine sandy loam, or clay loam.
The Bw horizon has a hue of 5YR through 10YR, value of 5 through 7, and chroma of 3 through 6. It is loam, clay loam, or sandy clay loam. Structure is compound weak or moderate coarse prismatic and weak or moderate fine or medium subangular blocky and granular.
The Bk horizons have a hue of 5YR through 10YR, value of 5 through 7, and chroma of 4 through 8. They are loam, sandy clay loam, or clay loam. The C1ca horizon contains 5 to 20 percent visible secondary carbonates in the form of soft bodies, films, threads, and concretions.
COMPETING SERIES: These include the Berda, Berthoud, Karnes, McAllen, Mansic, Midessa, Mobeetie, Ruella, Sabenyo, Seawillow, Spurlock, Veal, and Weymouth series. Berda, Mansic, Midessa, and Veal soils are dry in the moisture control section for longer periods. In addition, Berda soils, as well as Ruella soils, lack calcic horizons within 40 inches depth, Mansic soils have a mollic epipedon, and Veal soils, as well as Karnes and Seawillow soils, have carbonatic mineralogy. Berthoud and Spurlock soils have mean annual soil temperatures of less than 59 degrees F. Karnes and Mobeetie soils have less than 18 percent clay in the 10 to 40 inch control section. McAllen and Sabenyo soils have mean soil temperatures higher than 72 degrees F. Weymouth soils are less than 40 inches thick over clayey shale.
GEOGRAPHIC SETTING: These soils are on uplands mainly in footslope positions below receding limestone scarps. Slope gradients range from 1 to 15 percent, but are mostly 1 to 8 percent. The soil formed mainly in calcareous loamy colluvial and old alluvial sediments. Thornthwaite annual P-E indices are 32 to 50 and average annual precipitation ranges from about 21 to 34 inches. At the type location, the average annual temperature is about 66 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Weymouth series and the Mereta, Nuvalde, Rotan, and Vernon series. Mereta, Nuvalde, and Rotan soils have a mollic epipedon, and Mereta soils have a cemented caliche layer within 20-inch depth. In addition, Rotan soils have an argillic horizon. Vernon soils have more than 35 percent clay in the 10 to 40 inch control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Mostly in rangeland. Vegetation is mainly sideoats grama, little bluestem, black grama, hairy grama, reverchon panicum, buffalograss, threeawn, and yucca. A few areas are farmed to grain sorghum and cotton.
DISTRIBUTION AND EXTENT: Mainly in west and central Texas, below receding limestone scarps and on ancient terraces. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Taylor County, Texas; 1971.
REMARKS: These soils were formerly included in the Berda series, and classified in the Regosol great soil group.