LOCATION WOODWARD OK+KS+TXEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, thermic Typic Haplustepts
TYPICAL PEDON: Woodward loam, cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 10 inches; reddish brown (5YR 4/4) loam, dark reddish brown (5YR 3/4) moist; moderate medium granular structure; slightly hard, friable; many fine and medium roots; common wormcasts; slightly effervescent; moderately alkaline; gradual smooth boundary. (7 to 14 inches thick)
Bw--10 to 20 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; moderate medium granular structure; slightly hard, friable; many fine and medium roots; common wormcasts; slightly effervescent; moderately alkaline; gradual smooth boundary. (7 to 30 inches thick)
BCk--20 to 28 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; weak medium granular structure; slightly hard, friable; many fine roots; a few fragments of weathered sandstone in the lower part; few films of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. (2 to 10 inches thick)
Cd--28 to 60 inches; red (2.5YR 4/6) noncemented, slightly effervescent, moderately alkaline; sandstone bedrock; dark red (2.5YR 3/6) moist; cracks that roots can enter are more than 10 cm across.
TYPE LOCATION: Woodward County, Oklahoma; about 1/4 mile south of Ft. Supply; about 2,250 feet west and 450 feet north of the southeast corner of sec. 8, T. 24 N., R. 22 W.
RANGE IN CHARACTERISTICS: Solum thickness is 20 to 40 inches to sandstone bedrock. Depth to soft powdery secondary lime ranges from 0 to 36 inches of the soil surface. Typically the soil has slight to strong effervescence throughout. Gypsum content ranges from 0 to 3 percent.
The A horizon has hue of 2.5YR to 10YR, value of 4 to 6, and chroma of 3 to 6. The epipedon is less than 18 cm thick when the moist value and chroma is less than 3.5. The A horizon is loam, silt loam, or very fine sandy loam. Reaction is neutral through moderately alkaline. Content of calcium carbonate as nodules, masses, and threads ranges from 0 to 5 percent by volume. Calcium carbonate equivalent ranges from 0 to 10 percent by weight.
The Bw or Bk horizons have hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 3 to 8. Texture is loam, silt loam, or very fine sandy loam and reaction is slightly or moderately alkaline. Content of calcium carbonate as nodules, masses, and threads ranges from 0 to 10 percent by volume. Calcium carbonate equivalent ranges from 2 to 10 percent by weight.
The BC or BCk horizons have hue of 2.5YR to 7.5YR, value of 4 to 6, and chroma of 4 to 8. Texture is loam, silt loam, or very fine sandy loam and reaction is slightly or moderately alkaline. Content of calcium carbonate as nodules, masses, and threads ranges from 5 to 15 percent by volume. Calcium carbonate equivalent ranges from 2 to 15 percent by weight. Weakly cemented sandstone fragments, mainly less than 1 inch in diameter, range from 0 to 10 percent by volume.
The Cd horizon is noncemented reddish sandstone bedrock that is typically slightly effervescent but locally may be noneffervescent and slightly or moderately alkaline. This material is mainly non paralithic, however, some strata may be paralithic. Fractures that roots can enter in some part of this layer are greater than 10 cm apart. The bulk density is high enough to be root restrictive. This material has low to moderate excavation difficulty. Most of this material slakes in water within 1 hour.
COMPETING SERIES: These are the Deepwood, Enterprise and Gotebo series in the same family. Deepwood and Enterprise soils do not have sandstone bedrock within adepth of 40 inches. Gotebo soils have hues of 10YR or yellower throughout the B and C horizons.
GEOGRAPHIC SETTING: Woodward soils are on very gently sloping to moderately steep ridgecrests and side slopes of ridges and escarpments in the Central Rolling Red Plains (MLRA 78B, 78C). Slopes range from 1 to 30 percent. The soil formed in residuum weathered from sandstone bedrock of Permian age. Mean Annual Precipitation is 20 to 32 inches. Mean Annual Temperature is 57 to 63 degrees F. Thornthwaite Annual P-E indices range from 32 to 44. Frost free days range from 185 to 221. Elevation ranges from 1200 to 2300 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Deepwood, Enterprise and Gotebo series, and Aspermont, Carey, Dill, Hardeman, Obaro, Paducah, Quinlan Selman, Shrewder, Teagard and Wellsford series.
Aspermont and Obaro soils are on nearby slopes and have a fine-silty textural control section. Carey, Paducah, and Selman soils are on nearby slopes and have an argillic horizon and a fine-silty textural control section. Dill soils are on higher elevations and have a coarse-loamy textural control section. Deepwood and Enterprise soils lack sandstone within 50 inches. Hardeman soils are on similar positions but lack sandstone within 60 inches and have a coarse-loamy textural control section.. Gotebo soils are on similar positions but have hue of 10YR or yellower throughout the B and C horizons. Quinlan soils are on nearby ridgecrests and back slopes and are less than 20 inches to sandstone. Teagard and Wellsford soils have fine textural control sections and occur on higher landscape positions.
DRAINAGE AND PERMEABILITY: Woodward soils are well drained; permeability is moderate. Runoff is low on 1 to 5 percent slopes, medium on 5 to 20 percent slopes and high on slopes greater than 20 percent.
USE AND VEGETATION: More than one half is native range used for grazing beef cattle. Considerable acreage of Woodward on lesser slopes is used for growing cotton, small grains and sorghums. The native grasses are mainly little bluestem and gramas.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) of Oklahoma, Kansas, and Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Woodward County, Oklahoma; 1944.
REMARKS: Soil Interpretation Record: Series OK0071
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to a depth of approximately 10 inches (A horizon).
Cambic horizon - the zone from approximately 10 inches to 28 inches (Bw and BC horizons).
Densic contact at 28 inches, the top of the Cd layer.
Densic material 28 to 60 inches, the Cd layer.
ADDITIONAL DATA: Oklahoma State University Lab - Sample 75-OK-75-1-(1-4).
Taxonomic version: Keys to Soil Taxonomy, Ninth Edition, 2003.