LOCATION RENFROW OK+KS TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Udertic Paleustolls
TYPICAL PEDON: Renfrow silt loam--native range. (Colors are for dry soil unless otherwise stated.)
A--0 to 9 inches; brown (7.5YR 4/2) silt loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; hard, friable; many fine roots; slightly acid; gradual smooth boundary. (5 to 12 inches thick)
BA--9 to 13 inches; reddish brown (5YR 4/3) clay loam, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; hard, friable; many fine roots; slightly acid; clear smooth boundary. (3 to 10 inches thick)
Btss1--13 to 25 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate medium blocky structure; very hard, very firm; nearly continuous clay films on faces of peds; few slickensides; common fine roots; neutral; gradual smooth boundary. ( 8 to 20 inches thick)
Btss2--25 to 40 inches; reddish brown (2.5YR 4/4) clay, dark reddish brown (2.5YR 3/4) moist; moderate coarse blocky structure; extremely hard, very firm; nearly continuous clay films on faces of peds; common slickensides; few fine roots; calcareous at 30 inches; slightly alkaline; gradual smooth boundary. ( 8 to 25 inches thick)
Btss3--40 to 65 inches; red (2.5YR 4/6) clay, dark red (2.5YR 3/6) moist; weak coarse blocky structure; extremely hard, very firm; patchy clay films on faces of peds; few slickensides; few fine roots; few fine and medium concretions of calcium carbonate; few fine soft rounded bodies of calcium carbonate; calcareous; moderately alkaline; gradual smooth boundary. ( 0 to 33 inches thick)
C--65 to 75 inches; red (2.5YR 5/6) clay, red (2.5YR 4/6) moist; massive; extremely hard, very firm; calcareous; moderately alkaline.
TYPE LOCATION: Kay County, Oklahoma; about 4 miles south and 3 miles west of Tonkawa; 2,200 feet south and 50 feet east of the northwest corner of sec. 25, T. 25 N., R. 2 W.
RANGE IN CHARACTERISTICS: Solum thickness is more than 60 inches. Depth to secondary lime ranges from 20 to 50 inches. There are cracks within 125 cm of the mineral soil surface that are 5 mm or more wide through a thickness of 30 cm or more for some time in most years, and slickensides or wedge-shaped aggregates in a layer 15 cm or more thick that has its upper boundary within 125 cm of the mineral soil surface, or has a linear extensibility of 6.0 cm or more between the mineral soil surface and a depth of 100 cm.
The A horizon has hue of 5YR to 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is typically silt loam, but silty clay loam, clay loam, and loam are included. Reaction ranges from moderately acid to slightly alkaline.
The BA horizon has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 2 to 4. Texture is silty clay loam, clay loam or silt loam. Reaction ranges from slightly acid to slightly alkaline.
The Bt1 and Bt2 horizons have hue of 2.5YR or 5YR, value of 4 to 6 , and chroma of 3 to 6. Texture is typically clay but silty clay, silty clay loam, and clay loam are included. Clay content is typically 40 to 45 percent but ranges from 35 to 55 percent. Reaction ranges from slightly acid to moderately alkaline. Most pedons are calcareous in the lower part.
The Bt3 horizon has hue of 10R to 5YR, value of 4 to 6, and chroma of 3 to 8. Texture is similar to the Bt1 and Bt2 horizons. Reaction ranges from neutral to moderately alkaline.
Some pedons have a BC horizon that has hue of 10R to 5YR, value of 4 to 6, and chroma of 3 to 8. Texture is silty clay, clay, clay loam, or silty clay loam. Reaction is moderately alkaline and calcareous. Shale fragments 2 mm to 25 mm in diameter make up 0 to 15 percent by volume.
The C horizon has hue of 10R to 5YR, value of 4 to 6, and chroma of 6 to 8. Some pedons have redoximorphic concentrations and depletions in shades of brown, red, or gray in the C horizon. Some pedons have a Cr layer of consolidated shale below a depth of 60 inches.
COMPETING SERIES: These are Kirkland series in the same family. Kirkland soils have an abrupt textural change from the A horizon to the Bt horizon.
GEOGRAPHIC SETTING: Renfrow soils are on nearly level to gently sloping broad smooth convex ridges and side slopes of uplands in the Central Rolling Red Prairies. Slopes are mainly between 0 and 5 percent. These soils formed in material weathered from clayey shale of Permian age. The climate is dry or moist subhumid.
Mean Annual Temperature: 58 to 64 degrees F.
Mean Annual Precipitation: 26 to 40 inches.
Thornthwaite Annual P-E indices: 44 to 64.
Frost free days: 190 to 230.
Elevation: 900 to 1500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Bethany, Kirkland, Piedmont, Renthin, Grainola, Kingfisher, Masham, Stoneburg, Tabler, and Zaneis series. Bethany, Kirkland, and Tabler soils are on higher parts of the landscapes. In addition, Tabler soils have a mollic epipedon more than 20 inches thick. Piedmont and Renthin soils are typically on shoulder slopes, and have solum thickness of less than 60 inches. Grainola and Masham soils are typically on back slopes. Kingfisher, Stoneburg, and Zanies soils are on the same landscape. Grainola and Masham soils lack a mollic epipedon and have sola less than 60 inches thick; Kingfisher soils have a fine-silty control section. Stoneburg and Zaneis soils have a fine-loamy control section.
DRAINAGE AND PERMEABILITY: Well drained; runoff is high on 0 to 1 percent slopes and very high on 1 to 5 percent slopes; very slow permeability.
USE AND VEGETATION: Most areas are cultivated to wheat and other small grains; lesser amounts are in grain sorghum, cotton, and alfalfa. Native vegetation consists of tall and mid grasses.
DISTRIBUTION AND EXTENT: Central Rolling Red Prairies of Oklahoma, Kansas, and Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Grant County, Oklahoma 1931.
REMARKS: Soil Interpretation Record No. OK 0090
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of 13 inches (A horizon and BA horizon).
Argillic horizon - the zone from 13 inches to a depth of 65 inches (Bt horizons).
ADDITIONAL DATA: Lab. data from NSSL - S53OK-117-036, and S91OK-109-005.