LOCATION COLORADO TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, thermic Typic Ustifluvents
TYPICAL PEDON: Colorado silt loam--native pasture.
(Colors are for dry soil unless otherwise stated.)
A1--0 to 5 inches; light reddish brown (5YR 6/3) silt loam, reddish brown (5YR 4/3) moist; weak fine granular structure; soft, very friable; many fine roots; calcareous; moderately alkaline; abrupt smooth boundary. (4 to 14 inches thick)
C1--5 to 16 inches; light reddish brown (5YR 6/3) loam, (stratified with more clayey and more sandy strata) reddish brown (5YR 4/3) moist; massive; slightly hard; friable; earthworm casts
few to common; calcareous; moderately alkaline; diffuse smooth boundary. (10 to 30 inches thick)
C2--16 to 50 inches; light reddish brown (5YR 6/3) loam; massive; slightly hard; friable; stratified; calcareous;
moderately alkaline.
TYPE LOCATION: Runnels County, Texas; 3,400 feet southeast of the intersection of U. S. Highways 67 and 83 in Ballinger, 500 feet
east of U. S. Highway 83.
RANGE IN CHARACTERISTICS: The average texture of the 10 to 40
inch control section is silt loam, loam, sandy clay loam, or clay loam with 18 to 35 percent clay and more than 15 percent coarser
than very fine sand. Some pedons contain as much as 15 percent gravel. Stratification occurs throughout the soil.
The A horizon ranges in hue from 5YR to 10YR, value of 4 to 6, and chroma of 3 to 4. A horizons with moist values of chromas of less than 3.5 are less than 10 inches thick.
The C horizon ranges in hue from 2.5Y to 7.5YR, value 4 to 7, and chroma 3 to 8. In some pedons thin strata of hue 10YR occur in
the C horizons. In some pedons, part of the C1 horizon shows evidence of weak structural development, but is it not continuous enough to destroy all bedding planes.
COMPETING SERIES: These are the
Bunyan,
Clairemont,
Loire,
Mangum,
Norwood,
Pulaski,
Reinach,
Spur,
Yahola, and
Zavala
series. Bunyan, and Norwood soils are moist for longer periods of time than Colorado soils. Clairemont soils have less than 15
percent coarser than very fine sand. Loire soils as well as
Zavala soils have mean annual soil temperatures more than 72
degrees F. Within the 10 to 40 inch control section, Mangum soils have more than 35 percent clay and Pulaski, Yahola, and Zavala
soils have less than 18 percent clay. Reinach and Spur soils have moist values less than 3.5 to depths greater than 10 inches.
GEOGRAPHIC SETTING: These soils are on flood plains in semiarid
to dry subhumid southern parts of the Great Plains. The range of mean annual temperature is 64 degrees to 66 degrees F.; annual precipitation 17 to 28 inches, and Thornthwaite annual P-E indices
24 to 44. Slopes range from 0 to 1 percent.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Mangum, Clairemont, and Spur series.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability. Some areas have a ground water table within 20
feet. Flooding, usually severe but of short duration, occurs from
1 or more times per year to once in 10 years, unless protected.
USE AND VEGETATION: Mostly rangeland. Predominantly midgrasses
with scattered pecan and elm trees along stream channels.
DISTRIBUTION AND EXTENT: Dry subhumid to semiarid parts of
western Texas and possibly western Oklahoma.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Cottle Couny, Texas; 1970.
REMARKS: These soils were formerly included in Alluvial land.