LOCATION NIPSUM TX+OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Cumulic Haplustolls
TYPICAL PEDON: Nipsum clay--rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 10 inches; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; moderate fine subangular blocky and weak fine granular structure; hard, friable; few fine and medium roots; slightly effervescent; moderately alkaline; clear smooth boundary. (7 to 15 inches thick)
A2--10 to 30 inches; brown (7.5YR 5/2) clay, dark brown (7.5YR 3/2) moist; moderate medium and fine subangular blocky structure; hard, firm; common roots; many very fine pores; common wormcasts; few films and threads of calcium carbonate; slightly effervescent; moderately alkaline; gradual smooth boundary. (10 to 24 inches thick)
Bk1--30 to 48 inches; reddish brown (5YR 5/4) clay, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; hard, firm; about 3 percent by volume of calcium carbonate concretions; strongly effervescent; moderately alkaline; gradual smooth boundary. (8 to 30 inches thick)
Bk2--48 to 60 inches; reddish brown (5YR 5/4) clay, reddish brown (5YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, firm; common fine concretions and masses of calcium carbonate and gypsum crystals; strongly effervescent; moderately alkaline.
TYPE LOCATION: Stonewall County, Texas; from county courthouse in Aspermont, Texas; 3.6 miles south on U. S. Highway 83; east 4.5 miles on county road; 1.2 miles north and west on private ranch road and 200 feet north of private ranch road in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to 80 inches. The mollic epipedon ranges from 20 to 40 inches thick.
The A1 and A2 horizons have hue of 5YR to 10YR, value of 3 to 5, and chroma or 2 or 3. Texture is clay, silty clay, silty clay loam, or clay loam, with clay content ranging from 35 to 45 percent. Reaction is noneffervescent to strongly effervescent and is slightly alkaline or moderately alkaline.
The Bk1 horizon has hue of 5YR or 7.5YR, value of 4 to 6, and chroma of 2 to 6. Texture is clay, clay loam, silty clay loam, or silty clay and clay content ranges from 35 to 55 percent. Soft masses, films, threads and concretions of calcium carbonate comprise 3 to an estimated 20 percent by volume. Crystals of gypsum range from 1 to 10 percent by volume. Reaction is slightly effervescent to violently effervescent and is moderately alkaline.
The Bk2 horizon has hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 3 to 6. Texture is clay, clay loam, silty clay loam, or silty clay and clay content ranges from 28 to 55 percent. Masses, films, threads and concretions of calcium carbonate comprise an estimated 3 to 20 percent by volume. Crystals of gypsum range from 2 to 15 percent by volume. Reaction ranges from slightly effervescent to violently effervescent and is moderately alkaline.
COMPETING SERIES: These are the Clearfork and Westfork series. Similar soils include the Frio, Krum, Miller, Nukrum, Rioconcho, and Volente series.
Clearfork and Westfork soils are on floodplains. Westfork soils are in areas of higher precipitation.
Frio soils are on floodplains in areas of higher precipitation and have smectitic mineralogy.
Krum and Nukrum soils have vertic properties and smectitic mineralogy.
Miller and Rioconcho soils are on floodplains and have vertic properties.
Volente soils have a solum thickness less than 60 inches, a regular decrease in organic carbon, and fragments of limestone within 4 to 6 feet.
GEOGRAPHIC SETTING: Nipsum soils are on nearly level to gently sloping drainageways in uplands on which freshly accumulated sediments have been incorporated in the mollic epipedon. The soils have concave surfaces with gradients of 0.5 to 3 percent. The soils formed in clayey and loamy alluvium or colluvium that presently does not flood. Mean annual precipitation ranges from 20 to 26 inches. Mean annual temperature ranges from 60 to 64 degrees F. Elevation ranges from 1400 to 2200 feet. Frost free days range from 200 to 230. Thornthwaite annual P-E indices of 32 to 38.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acme, Aspermont, Cottonwood, Kingco, Knoco, Quanah, Talpa, Tilvern, Vernon, and Westill series. Acme and Cottonwood soils are less than 20 inches thick over gypsum. Aspermont, Knoco, Tilvern and Vernon soils have a ochric epipedon and have sola less than 60 inches thick. Kingco soils have slickenslides. Quanah soils have a mollic epipedon less than 20 inches thick. Talpa soils are less than 20 inches thick over limestone. Westill soils have a mollic epipedon less than 20 inches thick and have a argillic horizon. All of the associated soils occupy landscape positions higher than the Nipsum soils.
DRAINAGE AND PERMEABILITY: Well drained; permeability is slow; runoff is medium on slopes less than 1 percent and high on 1 to 3 percent slopes.
USE AND VEGETATION: Used mainly as rangeland, but some areas are cropped to wheat, sorghum, and cotton. Native vegetation is buffalograss, tobosa grass, silver bluestem, vine mesquite, blue grama, and sideoats grama. Prickly pear, mesquite, and lote bush have invaded some areas.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) of Texas and southwestern Oklahoma. The soil is of minor extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Stonewall County, Texas; 1970.
REMARKS: These soils were formerly classified as Chestnut soils intergrading to Alluvial great soil group.
Diagnostic horizons and features recognized in the pedon are:
Mollic epipedon - from the surface to a depth of 30 inches (the A1 and A2 horizons).
Cambic horizon - from a depth of 30 inches to 60 inches (the Bk1 and Bk2 horizons).
ADDITIONAL DATA: NSSL Data Sample No. 97OK065003 from Jackson County, OK.
Soil Interpretation Record: TX0621