LOCATION REDPORT OKEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Cumulic Hapludolls
TYPICAL PEDON: Redport silty clay loam--cultivated.
(Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark reddish brown (5YR 3/3) silty clay loam, reddish brown (5YR 4/3) dry; moderate fine granular structure; hard, friable; slightly effervescent, moderately alkaline; clear smooth boundary. (6 to 11 inches thick)
A1--9 to 17 inches; dark reddish brown (5YR 3/2) silty clay loam, dark reddish gray (5YR 4/2) dry; moderate fine subangular blocky structure; very hard, firm; material like that of horizon above in small cracks; slightly effervescent; moderately alkaline; gradual smooth boundary. (6 to 20 inches thick)
A2--17 to 31 inches; dark reddish brown (5YR 3/2) silty clay loam, dark reddish gray (5YR 4/2) dry; moderate fine granular structure; hard, firm; slightly effervscent; moderately alkaline; gradual smooth boundary. (10 to 20 inches thick)
Bw--31 to 44 inches; reddish brown (5YR 4/4) silty clay loam, reddish brown (5YR 5/4) dry; weak fine subangular blocky structure; very hard, firm; few dark stains on faces of peds; common fine threads of calcium carbonate; strongly effervscent; moderately alkaline; gradual smooth boundary. (10 to 20 inches thick)
C--44 to 74 inches; yellowish red (5YR 4/6) silty clay loam, yellowish red (5YR 5/6) dry; massive ; very hard, firm; few dark stains; slightly effervscent; moderately alkaline.
TYPE LOCATION: Bryan County, Oklahoma; about 18 miles southeast of Durant; about 2,580 feet west and 540 feet south of the northeast corner of sec. 13, T. 9 S., R. 10 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 36 to more than 60 inches. Thickness of the mollic epipedon ranges from 24 to 40 inches.
The A horizon has hue of 2.5YR or 5YR, value of 3, and chroma of 2 or 3. Texture is silt loam, clay loam, or silty clay loam. It is slightly or moderately alkaline.
The Bw horizon has hue of 2.5YR or 5YR, value of 3 to 5, and chroma of 3 to 6. It is silt loam, clay loam, or silty clay loam. Thin threads of calcium carbonate occur in most pedons and calcium carbonate concretions and dark stains occur in some pedons.
The C horizon has hue of 2.5YR or 5YR, value of 3 to 5, and chroma of 3 to 6 and has thin strata ranging from loamy fine sand through silty clay loam.
In some pedons an Ab horizon occurs below a depth of 24 inches. It has colors like the A horizon.
COMPETING SERIES: These are the Arrington and Verdigris series. Arrington soils have colors in hue of 7.5YR or more yellow and are noncalcareous. Verdigris soils are noncalcareous and lack reddish colors.
GEOGRAPHIC SETTING: Redport soils are on nearly level flood plains, mainly on streams that carry sediments of the Permian red beds, and some tributaries of the Pennsylvanian. Slopes range from 0 to 1 percent. They are occasionally flooded for very brief or brief periods during March through August. The soil formed in reddish loamy alluvium. Mean annual precipitation ranges from 40 to 52 inches. Mean annual temperature ranges from 60 to 64 degrees F. Thornthwaite annual P-E index ranges from 64 to 80. Frost free days range from 200 to 220.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Latanier, Okay, Oklared, Pledger, Redlake, Roebuck, Severn, and Ships series. Latanier, Redlake, and Ships soils are on the same terrace in slightly lower positions on the landscape farther from the main stream. Latanier, Pledger, Redlake, Roebuck, and Ships soils have more than 35 percent clay in the control section. Pledger and Roebuck soils are usually on the same terrace but on a lower landscape in back slough or concave positions. Also, Redlake soils lack a mollic epipedon. Okay soils have an argillic horizon and are on high terraces above overflow. Oklared and Severn soils are on lower terraces and have less than 18 percent clay in the control section.
DRAINAGE AND PERMEABILITY: Well drained; low runoff; moderate permeability.
USE AND VEGETATION: Mainly used for cropland. Soybeans, alfalfa, cotton, grain sorghums, and small grains are the main crops. Native vegetation is oak, elm, pecan, ash, and hackberry.
DISTRIBUTION AND EXTENT: Southeastern Oklahoma; possibly Arkansas, Louisiana, and Texas. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
Series Estalished: Bryan County, Oklahoma; 1974.
REMARKS: Redport soils previously were included in the Port series.
Soil Interpretation Record: Series OK0106
Diagnostic horizons and features recognized in this soil are:
Mollic epipedon - the zone from the surface of the soil to a depth of 31 inches (the A horizone).
Cumulic - a mollic epipedon on 60 cm or more thick with a texture finer than loamy fine sand.
Moisture regime - Udic.