LOCATION BLANKET TX+KSEstablished Series
TYPICAL PEDON: Blanket clay loam--cultivated.
(Colors are for dry soil unless otherwise
stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky and weak medium granular structure; slightly hard, firm; mildly alkaline; clear smooth boundary. (4 to 10 inches thick)
A--6 to 14 inches; very dark grayish brown (10YR 3/2) clay loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky and moderate medium granular structure; hard, firm; mildly alkaline; clear smooth boundary. (4 to 10 inches thick)
Bt1--14 to 30 inches; dark brown (10YR 3/3) clay loam, very dark brown (10YR 2/2) moist; moderate medium blocky structure; very hard, very firm; few fine pores; weak patchy clay films on faces of peds; mildly alkaline; gradual smooth boundary. (7 to 18 inches thick)
Bt2--30 to 40 inches; brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; moderate medium blocky structure; very hard, very firm; clay films on faces of peds are continueous in upper part and patchy in lower part; few threads of calcium carbonate; calcareous; moderately alkalne; gradual smooth boundary. (6 to 18 inches thick)
Bk--40 to 56 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, firm; many threads and few soft masses of calcium carbonate; calcareous; moderately alkaline; gradual smooth boundary. (12 to 20 inches thick)
Bck--56 to 72 inches; pale brown (10YR 6/3) clay loam, brown (10YR 5/3) moist; massive; hard, firm; many films and threads and common soft masses of calcium carbonate; common weakly cemented concretions of calcium carbonate; calcareous; moderately alkaline.
TYPE LOCATION: Erath County, Texas; from Morgan Mill, Texas; 8.5 miles north on U. S. Highway 281 to the junction of U. S. Highway 281 and Farm Road 2803; then 0.3 mile west on Farm Road 2803 and 75 feet north of road right-of-way in cultivated field.
RANGE IN CHARACTERISTICS: The solum ranges from 60 to about 80 inches thick. Secondary carbonates are below a depth of 28 inches. Some pedons contain a few siliceous pebbles throughout. The mollic epipedon is more than 20 inches thick.
The A horizon has hue of 7.5YR and 10YR, value of 2 through 5, and chroma of 2 or 3. Texture is silt loam, loam, silty clay loam, or clay loam. Reaction ranges from slightly acid through mildly alkaline.
The Bt horizon has hue of 5YR through 10YR, value of 2 through 5, chroma of 2 or 3. Texture is silty clay loam, silty clay, clay, or clay loam with a clay content ranging from 35 to about 50 percent. Reaction ranges from slightly acid through mildly alkaline in the upper part and from slightly acid through moderately alkaline and calcareous in the lower part.
The Bk and BCk horizons have colors in shades of gray, brown, or yellow. Texture is clay loam, silty clay loam, silty clay, or clay. Some pedons contain strata of loam on sandy clay loam. Reaction is moderately alkaline and calcareous. The BCk horizon contains more than 20 percent visible films, threads, soft masses, or concretions of calcium carbonate.
COMPETING SERIES: These include Abilene, Brewer, Dodson, McLain, Mingo, and Wolco series in the same family and the similar Luckenbach and Thurber series. Abilene and Luckenbach soils have secondary carbonates within 28 inches of the soil surface. In addition, Luckenbach soils have a mollic epipedon less than 20 inches thick. Brewer, Dodson, and McLain soils have less than 20 percent calcium carbonate in the C horizon. Mingo soils have a lithic contact of limestone within 22 to 40 inches of the soil surface. Wolco soils have a lithic contact of limestone within 40 to 60 inches of the soil surface. Thurber soils have an epipedon that is both massive and hard when dry and montmorillonitic mineralogy.
GEOGRAPHIC SETTING: Blanket soils are on nearly level and gently sloping, plane to concave surfaces of broad upland valleys. Slopes range from 0 to 4 percent. The soil is formed in ancient stream alluvium. Average annual precipitation ranges from 25 to 35 inches and the Thornthwaite annual P-E indices range from 36 to 54. The mean annual temperature is 58 to 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Thurber series and Bosque, Frio, May, Pedernales, Santo, Velow, and Windthorst series. Bosque, Frio, and Santo soils are below on flood plains and these soils lack argillic horizons. May, Thurber, and Velow soils are on positions similar to Blanket soils. May and Velow soils have fine-loamy control sections.
Pedernales and Windthorst soils are above Blanket soils on low ridges or slopes along drainageways. Pedernales and Windthorst soils lack mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; very slow to slow runoff; slow internal drainage; moderately slow permeability.
USE AND VEGETATION: Mostly cultivated with small grains and sorghums being the main crops. Native grasses include little bluestem, sideoats grama, and buffalograss. Woody vegetation includes mesquite, live oak, and post oak trees.
DISTRIBUTION AND EXTENT: North-central Texas, mainly along the transition from the Grand Prairie to the Cross Timbers and south-central Kansas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Brown County, Texas; 1939.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the A and upper Bt horizons from 0 to 30 inches.
Argillic horizon - the Bt horizons from 14 to 40 inches.
Other- accumulation of carbonates in the Bk horizons is insufficient for a calcic horizon.
ADDITIONAL DATA: Lincoln Lab. Data: 72L745-72L750.