LOCATION HIGHBANK           TX
Established Series
Rev. WGC-ACT
02/2001

HIGHBANK SERIES


The Highbank series consists of very deep, well drained, slowly permeable soils that formed in clayey alluvium. These soils are on nearly level flood plains of the Brazos River. Slopes range from 0 to 1 percent.

TAXONOMIC CLASS: Fine, mixed, active, thermic Udertic Haplustepts

TYPICAL PEDON: Highbank silty clay loam - cropland. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 6 inches; reddish brown (5YR 4/4) silty clay loam, dark reddish brown (5YR 3/4) moist; weak fine granular structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine pores; many wormcasts; strongly effervescent; moderately alkaline; abrupt smooth boundary. (4 to 10 inches thick)

A--6 to 14 inches; reddish brown (5YR 4/4) silty clay loam, dark reddish brown (5YR 3/4) moist; weak fine and medium subangular blocky structure; hard, friable, sticky and plastic; many very fine and fine roots; many very fine pores; few fragments of snail shells; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 10 inches thick)

Bw1--14 to 24 inches; reddish brown (5YR 5/4) silty clay, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; few very fine pores; few fragments of snail shells; common bedding planes; strongly effervescent; moderately alkaline; abrupt smooth boundary.

Bw2--24 to 48 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate medium angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine and fine roots; few very fine pores; common pressure faces; few bedding planes; strongly effervescent; moderately alkaline; gradual smooth boundary.

Bw3--48 to 56 inches; reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/3) moist; weak medium angular blocky structure; very hard, very firm, very sticky and very plastic; few fine roots; few very fine pores; few small slickensides; common pressure faces; few bedding planes; strongly effervescent; moderately alkaline; gradual smooth boundary. (combined thickness of the Bw horizon is 20 to 65 inches)

BC--56 to -62 inches; reddish brown (5YR 4/3) silty clay, dark reddish brown (5YR 3/3) moist; weak medium subangular blocky structure; very hard, very firm, very sticky and very plastic; few fine roots; few very fine pores; few pressure faces; few fine and medium concretions of calcium carbonate; strongly effervescent; moderately alkaline. (0 to 12 inches thick)

C/B--62 to 80 inches, stratified layers of yellowish red (5YR 5/6) silt loam and reddish brown (5YR 4/4) silty clay; layers are less than an inch to about 4 inches thick; layers thicker than 2 inches, about 25 percent, have weak medium subangular or angular blocky structure (B); few fine roots; few fine concretions of calcium carbonate; strongly effervescent; moderately alkaline.

TYPE LOCATION: Falls County, Texas; from the intersection of Texas Highway 6 and Texas Highway 7 in Marlin, Texas, 2.4 miles west on Texas Highway 7; then northwest on a county road 0.2 mile and 50 feet north of county road in a field.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to about 80 inches. Clay content of the control section ranges from 40 to 60 percent. Reaction is slightly or moderately alkaline and it is slightly or strongly effervescent throughout. Bedding planes or thin discontinuous stratification ranges from faint to distinct in some part of the control section. The soil is dry in the moisture control section for less than 110 cumulative days during the growing season in most years.

The A horizon has hue of 5YR or 7.5YR, value of 4 to 6, and chroma of 3 to 6. Horizons with mollic colors are less than 10 inches thick. Texture is silt loam or silty clay loam.

The Bw horizon has hue of 2.5YR or 5YR, value of 4 to 6, and chroma of 3 to 6. Texture is silty clay or clay. Pressure faces and small slickensides range from none to common. Some pedons contain few very fine to medium concretions of calcium carbonate. Very fine or fine fragments of shells range from none to few.

The BC horizon, when present, has colors in shades of red or brown. Texture is silty clay loam, silty clay or clay. Very fine and fine concretions of calcium carbonate range from none to few.

The C/B horizon is stratified layers of silt loam, silty loam, silty clay, and clay. The layers are less than an inch to about 6 inches thick. Layers thicker than about 2 inches typically have structure. Some pedons have very fine sandy loam to loamy fine sand strata. However, the average texture is silt loam or silty clay loam. Very fine and fine concretions of calcium carbonate range from none to few.

COMPETING SERIES: There are no other competing series. Similar soils are the Aspermont, Clairemont, Clemville, Ellis, Mangum, Ships, and Weswood series. Aspermont, Clairemont, and Clemville soils have fine-silty control sections. Ellis soils have montmorillonitic mineralogy. Mangum soils are dry in the moisture control section for more than 110 cumulative days during the growing season in most years. Ships soils have more than 60 percent clay in the control section, and have strongly expressed vertic features. Weswood soils have coarse-silty control sections.

GEOGRAPHIC SETTING: Highbank soils are on nearly level flood plains of the Brazos River. Slopes are mostly less than 1 percent. The soil formed in loamy and clayey alluvium. Mean annual temperature ranges from 66 to 69 degrees F., and mean annual precipitation ranges from 34 to 40 inches. Frost free days range from 270 to 280. Elevation ranges from 200 to 350 feet. Thornthwaite P-E index ranges from 54 to 64.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Roetex, Ships, Weswood, and Yahola series. Roetex soils have vertic properties and very fine control sections. Yahola soils have coarse-loamy control sections. Ships and Weswood soils are on similar positions. Roetex soils are in slightly lower wetter positions. Yahola soils are in similar or slightly lower positions closer to the river.

DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is low. Flooding ranges from rare to occasional.

USE AND VEGETATION: Used mainly for cropland. Crops consists of cotton, corn, grain sorghum, and oats. Some areas are producing bermudagrass pastures. Native vegetation includes pecan, cottonwood, elm, oak, and hackberry trees along with tall native grasses.

DISTRIBUTION AND EXTENT: Mainly along the Brazos River in central Texas. The series is of minor extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Falls County, Texas; 1975.

REMARKS: Classification change from Fluventic Ustochrepts to Udertic Ustochrepts based on local laboratory data. Data indicates linear extensibility is greater than 6.0 cm in the majority of pedons.

Active cation exchange activity class.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - 0 to 14 inches (Ap and A horizons).

Cambic horizon - 14 to 62 inches (Bw1, Bw2, Bw3, BC horizons).

Vertic feature - linear extensibility greater than 6.0 cm within 40 inches.

Soil Interpretation Record: TX0310


National Cooperative Soil Survey
U.S.A.