LOCATION OPELIKA TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, hyperthermic Mollic Albaqualfs
TYPICAL PEDON: Opelika fine sandy loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 4 inches; gray (10YR 5/1) fine sandy loam, very dark gray (10YR 3/1) moist; few fine faint brown stains along root channels; massive; very hard, friable; many fine roots; few fine pores; few wormcasts; neutral; abrupt smooth boundary. (3 to 8 inches thick)
B21t--4 to 10 inches; dark gray (10YR 4/1) sandy clay, very dark gray (10YR 3/1) moist; moderate coarse prismatic structure; parting to moderate medium blocky; extremely hard, firm; few fine roots mostly between faces of prisms; few fine pores; thick continuous clay films on faces of prisms; vertical faces of prisms partially coated with clean sand grains; mildly alkaline; clear wavy boundary. (3 to 14 inches thick)
B22t--10 to 19 inches; dark gray (10YR 4/1) sandy clay loam, very dark gray (10YR 3/1) moist; moderate coarse prismatic structure; parting to moderate medium blocky; very hard, firm; few fine roots and pores; thick patchy clay films on faces of prisms; vertical faces of prisms partially coated with clean sand grains; few fine soft bodies of calcium carbonate in lower part; moderately alkaline; gradual wavy boundary. (6 to 17 inches thick)
B23tca--19 to 30 inches; gray (10YR 5/1) sandy clay loam, dark gray (10YR 4/1) moist; weak fine and medium subangular blocky structure; hard, friable; common fine pores; common streaks of light brownish gray (10YR 6/2) material; common soft bodies of calcium carbonate; calcareous; moderately alkaline; gradual wavy boundary. (6 to 13 inches thick)
C--30 to 60 inches; light gray (10YR 7/2) sandy clay loam, light brownish gray (10YR 6/2) moist; few very fine faint yellowish mottles; massive; hard, friable; common fine pores; few soft bodies of calcium carbonate; calcareous; moderately alkaline.
TYPE LOCATION: Jim Wells County, Texas; 1.6 miles south on U. S. Highway 281 from its intersection with State Highway 141, 1.25 miles west-northwest on ranch road, 0.3 mile south along pipeline and 100 feet east in pasture. Site is about 16 miles south of Alice.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 24 to 44 inches. Depth to secondary carbonates ranges from 16 to 30 inches. Clay content of the upper 20 inches of the Bt horizon averages 29 to 35 percent.
The A horizon is dark gray (10YR 4/1), gray (10YR 5/1), grayish brown (10YR 5/2), or dark grayish brown (10YR 4/2) fine sandy loam, sandy clay loam, clay loam, or loam. It is massive and hard when dry. Some pedons have weak subangular structure when moist. Exchangeable sodium percentage ranges from 1 to 6 and soil salinity is less than 2 mmhos/cm. Reaction is neutral or mildly alkaline.
The B21t horizon is dark gray (10YR 4/1), gray (10YR 5/1), grayish brown (10YR 5/2), or dark grayish brown (10YR 4/2) sandy clay, sandy clay loam, or clay loam. Some pedons have B21t horizons of sandy clay or clay loam with more than 35 percent clay that are less than 10 inches thick. Prism tops are commonly slightly rounded and capped with a thin sandy layer. Exchangeable sodium percentage ranges from 1 to 6 and the soil salinity is less than 2 mmhos/cm. Reaction is neutral or mildly alkaline.
The B22t and B23t horizons are dark gray (10YR 4/1), gray (10YR 5/1), grayish brown (10YR 5/2), or light brownish gray (10YR 6/2) sandy clay loam or clay loam. Soil salinity increases slightly with depth but is less than 4 mmhos/cm. Exchangeable sodium percentage ranges from about 2 to 10. Reaction is mildly or moderately alkaline. Few to common soft bodies and fine concretions occur in the lower part of the B22t and in the B23t horizon.
The C horizon is gray (10YR 5/1, 6/1), light brownish gray (10YR 6/2), light gray (10YR 7/2), white (10YR 8/2), or pale brown (10YR 6/3) sandy clay loam or clay loam. It contains few to common soft bodies and concretions of calcium carbonate.
COMPETING SERIES: These include the Anahuac, Arol, Edna, Emeraldo, Falba, Hasse, Orelia, Mabank, Parrons, Taloka, and Telferner series. Anahuac, Arol, Edna, Falba, Hasse, Mabank, Parrons, and Taloka soils have more than 35 percent clay in the control section and have average annual soil temperatures less than 72 degrees F. Emeraldo and Telferner soils have more than 35 percent clay in their control sections. Orelia soils do not have an abrupt texture change between the A and Bt horizons.
GEOGRAPHIC SETTING: Opelika soils occupy nearly level, slightly concave, weakly expressed drainageways and nearly level low terraces on uplands adjacent to the drainageways. Slopes are less than 1.0 percent. The soil formed in clayey and loamy marine sediments like those of the Lissie and Beaumont formation. The mean annual temperature is 70 degrees to 75 degrees F. Average annual precipitation ranges from 20 to 30 inches and the Thornthwaite P-E index ranges from 24 to 40.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Orelia series and the Clareville, Czar, Delfina, Edroy, Lattas, Papagua, Papalote, and Racombes series. All these soils except Edroy, Orelia, and Papagua soils lack an aquic moisture regime. Clareville and Lattas soils occur on adjoining plains and have more than 35 percent clay in their control sections. Edroy, Papagua, and Racombes soils are in slightly depressed areas and Edroy and Papagua soils have more than 35 percent clay in their control Sections. Czar and Delfina soils are on slightly adjoining plains. Czar soils have a mollic epipedon. Delfina soils have a thicker, lighter colored A horizon and mottled Bt horizons.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; very slowly permeable.
USE AND VEGETATION: Used about equally for rangeland and pastureland. Some areas are cultivated to grain sorghum and cotton. Native grasses include two and fourflower trichloris, vine-mesquite, hooded windmillgrass, and lovegrass tridens. Woody vegetation is mainly mesquite, huisache, blackbrush, spiny hackberry, and pricklypear
DISTRIBUTION AND EXTENT: Central and eastern portions of the Rio Grande Plain of Texas. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jim Wells County, Texas; 1976.
REMARKS: The soils were formerly included with the Orelia series and were formerly classified in the Planosol great soil group.