LOCATION HARDEMAN TX+OKEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Haplustepts
TYPICAL PEDON: Hardeman fine sandy loam--cropland. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 10 inches; brown (7.5YR 5/4) fine sandy loam, brown (7.5YR 4/4) moist; weak fine granular structure; soft, very friable; common fine roots, slightly alkaline; clear smooth boundary. (0 to 12 inches thick)
Bw--10 to 18 inches; reddish brown (5YR 4/4) fine sandy loam, dark reddish brown (5YR 3/4) moist; compound weak medium subangular blocky and granular structure; slightly hard, very friable; few fine roots; few fine pores; slightly effervescent; moderately alkaline; clear smooth boundary. (8 to 18 inches thick)
Bk1--18 to 36 inches; reddish brown (5YR 5/4) fine sandy loam, dark reddish brown (5YR 3/4) moist; compound weak coarse prismatic and medium subangular blocky structure; slightly hard, very friable; few fine roots; few fine pores; many films and threads of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (12 to 30 inches thick)
Bk2--36 to 64 inches; reddish brown (5YR 5/4) fine sandy loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure; slightly hard, very friable; few fine pores; few faint films and threads of calcium carbonate in upper part; strongly effervescent; moderately alkaline
TYPE LOCATION: Hardeman County, Texas; from the intersection of U.S. Highway 287 and Farm Road 680, 0.6 mile west of Goodlett; 11.5 miles north, 3 miles west, and 3.8 miles north on Farm Road 680; 100 feet west in cultivated field.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 60 to more than 80 inches. Depth to carbonates ranges from 0 to 28 inches. The particle-size control section ranges from 12 to 18 percent clay and more than 15 percent of the sands are coarser than very fine sand. Siliceous gravel, mainly less than 1.5 inches across the long axis, ranges from 0 to 10 percent throughout the solum.
The A horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 to 4. Texture is mostly fine sandy loam or sandy loam, but loam and very fine sandy loam are included. Mollic surface horizons are less than 10 inches thick. Reaction ranges from neutral to moderately alkaline.
The Bw horizon has hue of 5YR or 7.5YR, value of 4 to 6, and chroma of 3 to 6. Texture is fine sandy loam, sandy loam, loam, or very fine sandy loam. Reaction ranges from neutral to moderately alkaline and is noneffervesent to slightly effervesent.
The Bk1 horizon has hue of 2.5YR to 7.5YR, value of 4 to 7, and chroma of 4 to 6. Texture is fine sandy loam, sandy loam, loam, or very fine sandy loam. Reaction is slightly alkaline or moderately alkaline and is slightly effervescent to strongly effervescent.
The Bk2 horizon has hue of 2.5YR to 7.5YR, value of 4 to 7, chroma of 4 to 8. Texture is fine sandy loam, sandy loam, or loam. Carbonates range from barely visible films and threads to about 5 percent in soft powdery forms. Some pedons have buried layers of sandy clay loam, sandy loam or loamy sand below 40 inches. Reaction is slightly alkaline or moderately alkaline and is slightly effervescent to strongly effervescent.
COMPETING SERIES: This is the Dill, Hext, and Shrewder series in the same family. Similar soils are the Deepwood, Enterprise, Mobeetie, Spade, Springer, and Woodward series.
Dill and Hext soils are moderately deep over weakly cemented sandstone, in addition Dill soils are noneffervescent throughout the solum. Deepwood, Enterprise and Woodward soils have less than 15 percent coarser than very fine sand in the control section. Mobeetie soils are strongly effervescent throughout and are dry in some part of the control section for more than half of the time during most years. Spade soils have sandstone within 20 to 48 inches. Springer soils have argillic horizons. Shrewder soils do not have secondary carbonates within 28 inches, and have soft sandstone within 80 inches.
GEOGRAPHIC SETTING: The Hardeman soils are on nearly level to moderately steep terrace pediments on uplands having convex to plane surfaces. Slopes are mostly 1 to 4 percent, but range from 0 to 20 percent. The soil formed in moderately coarse textured sediments mainly of alluvial origin. Most of the deposits have been reworked by wind. An eolian mantle is common to many areas. Mean annual precipitation ranges from about 20 to 28 inches. Mean annual temperature ranges from 57 to 64 degrees F. Elevation ranges from 1000 to 2200 feet. Frost free days range from 190 to 230. The Thornthwaite P-E indices ranges from 32 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arnett, Enterprise, Deepwood, Devol, Grandfield, Hilgrave, Jester, Miles, Quinlan, Shrewder, Springer, Tivoli and Woodward series.
Arnett, Devol, Grandfield, Hilgrave, Miles and Springer soils have a argillic horizon and are higher in the landscape. In addition, the Arnett, Grandfield, Hilgrave, and Miles soils have more than 18 percent clay in the argillic horizon. Deepwood, Enterprise and Woodward soils have coarse-silty control sections and are on similar landscape positions. Quinlan soils have bedrock at less than 20 inches and are on higher landscape positions. Shrewder soils do not have secondary calcium carbonates within 28 inches and are on similar landscapes. Jester and Tivoli soils are sandy throughout and do not have a B horizon.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability; runoff is negligible on slopes less than 1 percent, very low on 1 to 5 percent slopes, and low on 5 to 20 percent slopes.
USE AND VEGETATION: Slopes less than 5 percent are used mostly for sorghum, cotton, and wheat production. Native vegetation is mostly grama grasses, little bluestem, sand dropseed, and buffalograss in southern areas. Northern areas also include sand bluestem, switchgrass, indiangrass and sand lovegrass. Sand sagebrush is a common invader.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) of Texas and Oklahoma. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hardeman County, Texas; 1966.
REMARKS: Hardeman soils were previously included with the Enterprise series. They were classified in the Regosol great soil group
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the Ap horizon from 0 to 10 inches.
Cambic horizon - the Bw and Bk horizons.
Soil Interpretation Record: TX0292
ADDITIONAL DATA: NSSL data from Jackson County, OK (S97OK-065-005)