LOCATION MULDROW OK+AR MO TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Typic Argiaquolls
TYPICAL PEDON: Muldrow silty clay loam - cultivated.
(Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (10YR 5/2) dry; moderate medium and coarse granular structure; hard, firm; few fine roots; moderately acid; abrupt smooth boundary. (0 to 8 inches thick)
A--6 to 18 inches; very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm; few fine roots and pores; moderately acid; gradual smooth boundary. (10 to 18 inches thick)
Btg--18 to 50 inches; very dark gray (10YR 3/1) silty clay, dark gray (10YR 4/1) dry; common fine distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) redoximorphic concentrations; moderate fine blocky structure; extremely hard, very firm; few fine roots and pores; faces of peds are shiny; neutral; diffuse smooth boundary. (25 to 40 inches thick)
BCg--50 to 70 inches; dark grayish brown (10YR 4/2) silty clay, grayish brown (10YR 5/2) dry; common coarse distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) redoximorphic concentrations; weak medium blocky structure; extremely hard, very firm; faces of peds are shiny; neutral.
TYPE LOCATION: Sequoyah County, Oklahoma; about one mile northwest of Moffett; 60 feet west and 300 feet north of the southeast corner of sec. 20, T. 11 N., R. 27 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to more than 70 inches. The A horizon has hue of 7.5YR or 10YR, value of 2 or 3, and chroma of 1 or 2. It is mainly silty clay loam but ranges to clay loam and silt loam. This horizon is strongly acid to neutral.
The Btg horizon has hue of 7.5YR or 10YR, value of 2 to 4, and chroma of 1 or 2. Redoximorphic concentrations are distinct or prominent and are light yellowish brown, yellowish brown, strong brown, or reddish brown. Some pedons have faint gray or light gray redoximorphic concentrations. The Btg horizon is silty clay loam, clay loam, silty clay, or clay; clay content is 35 to 50 percent and sand content is less than 30 percent. Reaction ranges from slightly acid to slightly alkaline.
The BCg horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 1 to 4 with redoximorphic concentrations in shades of brown, red, or brown. It is similar to the Btg horizon in texture. It ranges from neutral through moderately alkaline. Some pedons have a C layer with color, texture, and reaction similar to the BCg horizon.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Muldrow soils are on level to slightly concave low stream terraces. Slopes are mainly between 0 and 1 percent. They formed in predominantly clayey alluvium. They are rarely flooded. The climate is humid. At the type location the average annual precipitation ranges from 38 to 50 inches, the Thornthwaite P-E index ranges from 64 to 80, and the mean annual temperature ranges from 58 to 64 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Garton and Mason series. Garton and Mason soils are on landscapes closer to the streams and they have a udic moisture regime. In addition, Mason soils have a fine-silty control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; runoff is medium; permeability is very slow. A water table is at 0.0 to 2.0 feet for very brief periods of time during September through March.
USE AND VEGETATION: Largely cultivated to soybeans and small grains; lesser amounts are in alfalfa, cotton, grain sorghum, and tame pasture. Native vegetation is mixed hardwoods with an understory of grasses.
DISTRIBUTION AND EXTENT: Southwestern Missouri, and eastern Oklahoma. Mainly in the Arkansas River valley. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Sequoyah County, Oklahoma; 1970.
REMARKS: Soil Interpretation Record: Series OK0117
Diagnostic horizons and features recognized in this profile are:
Mollic epipedon - the zone from the surface of the soil to approximatley 50 inches. (A and Btg horizons)
Argillic horizon - the zone from 18 to 50 inches. (Btg horizon)