LOCATION BURFORD OKEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Typic Haplustepts
TYPICAL PEDON: Burford silt loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 9 inches; reddish brown (5YR 4/4) silt loam, dark reddish brown (5YR 3/4) moist; moderate fine and medium granular structure; hard, friable; many fine roots; common wormcasts; very few very fine nodules of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (5 to 15 inches thick)
Bw--9 to 19 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, very firm; common fine roots; common wormcasts; few fine nodules of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (7 to 22 inches thick)
Bk--19 to 25 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; very hard, very firm; few fine roots; common and medium soft masses and nodules of calcium carbonate, approximately 15 percent by volume; strongly effervescent; moderately alkaline; clear smooth boundary. (8 to 28 inches thick)
2BCk--25 to 32 inches; reddish brown (2.5YR 4/4) clay, dark red (2.5YR 3/6) moist; strong fine and medium angular blocky structure; extremely hard, extremely firm; few fine roots; few fine and medium nodules and threads of calcium carbonate, approximately 7 percent by volume; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 12 inches thick)
2C--32 to 42 inches; red (2.5YR 4/6) shaly clay, dark red (2.5YR 3/6) moist; massive; extremely hard, extremely firm; few fine roots in cracks; common threads of calcium carbonate; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 25 inches thick)
2Cd--42 to 80 inches; red (2.5YR 4/6) interbedded shale and shaly clay, dark red (2.5YR 3/6) moist; massive; extremely hard, extremely firm; many seams of gypsum crystals; common thin strata and pockets of blueish-gray shale; strongly effervescent; moderately alkaline.
TYPE LOCATION: Woods County, Oklahoma; 6 miles east and 2 miles south of Freedom Oklahoma; 3500 feet north and 2180 feet west of the southeast corner of sec. 10, T. 26 N., R. 17 W.
RANGE IN CHARACTERISTICS: Solum thickness (depth to C material) ranges from 24 to 50 inches. Depth to a visible calcium carbonate accumulation ranges from 5 to 32 inches. A lithologic discontinuity occurs between a depth of 24 to 60 inches. Reaction is slightly or moderately alkaline in the A and 2Cd horizons and moderately alkaline throughout the remainder of the soil.
The A horizon has hue of 2.5YR through 7.5YR, value of 4 through 6, and chroma of 3 through 6. Texture is loam, silt loam, clay loam, or silty clay loam. Calcium Carbonate Equivalent ranges from 0 to 10 percent. Clay content ranges from 18 to 35 percent clay.
The Bw horizon has hue of 2.5YR through 7.5YR, value of 4 through 6, and chroma of 3 through 6. Texture is loam, silt loam, clay loam, or silty clay loam. Secondary carbonates range from 0 to 2 percent by volume in the form of films, fine nodules, and small soft masses. The Calcium Carbonate Equivalent ranges from 2 to 15 percent. Clay content ranges from 20 to 40 percent.
The Bk horizon has hue of 2.5YR or 5YR, value of 4 through 6, and chroma of 3 through 6. It is loam, silt loam, silty clay loam, or clay loam. Secondary carbonates range from 5 to 30 percent by volume in the form of films, nodules, and soft masses. Calcium Carbonate Equivalent ranges from 5 to 20 percent. Clay content ranges from 20 to 40 percent.
The BC and 2BC horizon has hue of 2.5YR or 5YR, value of 4 through 6, and chroma of 4 or 6. It is clay loam, clay, or silty clay loam. Secondary carbonates range from 0 to 10 percent by volume in the form of threads, soft masses, films and nodules. Calcium Carbonate Equivalent ranges from 5 to 15 percent. Clay content ranges from 27 to 50 percent.
The 2C layer has hue of 2.5YR or 5YR, value of 4 through 6, and chroma of 4 or 6. It is clay loam, silty clay loam, or clay. Secondary carbonates, when present, are in the form of fine soft masses, seams, and threads and range from 0 to 10 percent by volume. The Calcium Carbonate Equivalent ranges from 5 to 15 percent. Clay content ranges from 27 to 50 percent.
The 2Cd layer is weathered silty shale, siltstone, and sandstone that is interbedded. Colors are similar to the C horizon. This material is Cr-nonparalithic. It has rock-like structure and the bulk density is high enough to be root restrictive. Cracks or fractures may be less than 10cm apart or more than 10cm apart. Excavation difficulty is low or moderate. This material slakes in water within 15 hours. The Calcium Carbonate Equivalent ranges from 5 to 15 percent.
COMPETING SERIES: These are the Aspermont and Obaro soils in the same family. Aspermont soils do not have paralithic contact between 40 and 60 inches. Obaro soils have weakly cemented sandstone within 40 inches of the surface.
GEOGRAPHIC SETTING: Burford soils are on gently sloping to steep uplands with slopes ranging from 1 to 20 percent. They formed in calcareous loamy alluvial or colluvial material overlying silty redbeds. The climate is dry subhumid, Mean average annual rainfall ranges from 22 to 28 inches and mean annual temperature ranges from 57 to 64 degrees F. Frost free days range from 190 to 230 days and elevation ranges from 1000 to 2000 feet. Thornthwaite annual P-E indices range from 32 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carey, Jaywi, Tillman, Vernon, and Woodward series. Carey soils have mollic epipedons and Bt horizons. Jaywi soils have sola thicker than 60 inches. Tillman soils have mollic epipedons and Bt horizons. Vernon soils have more than 35 percent clay in the 10 to 40 inch textural control. Woodward soils have less than 18 percent clay in the 10 to 40 inch textural control.
DRAINAGE AND PERMEABILITY: Well drained; runoff is high on 1 to 5 percent slopes and very high on slopes greater than 5 percent; Permeability is slow.
USE AND VEGETATION: Used mainly for rangeland. Minor use is devoted to cotton, wheat, and grain sorghum. Native vegetation consists mainly of short grasses with some midgrasses.
DISTRIBUTION AND EXTENT: Rolling Red Plains (MLRA's 78B, 78C, and 78D) of Texas and Oklahoma. The soil is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Woods County, Oklahoma; 1995.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 9 inches. (A horizon)
Cambic horizon - 9 to 25 inches. (Bw horizon)
Lithologic discontinuity - 25 inches.
Soil Interpretive Record Number - OK0426