LOCATION TREADWAY OK+TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Gypsic Haplustepts
TYPICAL PEDON: Treadway silty clay loam, on a nearly level toe slope, in native range. (Colors are for dry soil unless otherwise stated.)
A1--0 to 2 inches; reddish brown (5YR 5/3) silty clay loam, reddish brown (5YR 4/3) moist; moderate medium platy structure; firm, hard; common fine and very fine and common medium roots; many fine and common medium pores; 1 percent shale fragments; very slight effervescence; moderately alkaline; abrupt smooth boundary.
A2--2 to 13 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; moderate coarse platy structure; very firm, extremely hard; common fine and very fine and common medium roots; many fine and common medium pores; 1 percent fine carbonate masses; 1 percent fine gypsum crystals, by volume; 1 percent gypsum, by weight; 1 percent fine crystals of other salts; very slightly saline; slightly sodic; 1 percent shale fragments; slight effervescence; moderately alkaline; gradual smooth boundary. (combined thickness of the A horizon : 5 to 15 inches thick)
Bkyz1--13 to 24 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak medium prismatic structure parting to moderate fine subangular blocky; very firm, extremely hard; common fine and very fine and few medium roots; common fine and few medium pores; 1 percent fine carbonate masses; 10 percent fine gypsum crystals, by volume; 9 percent gypsum, by weight; 2 percent fine crystals of other salts; slightly saline; slightly sodic; 1 percent shale fragments; slight effervescence; moderately alkaline; gradual smooth boundary.
Bkyz2--24 to 37 inches; reddish brown (5YR 5/3) silty clay, reddish brown (5YR 4/3) moist; weak coarse prismatic structure parting to weak medium angular blocky; very firm, extremely hard; common fine and very fine and few medium roots; few fine and very fine pores; 15 percent distinct pressure faces; 1 percent fine carbonate masses; 3 percent fine gypsum crystals, by volume; 2 percent gypsum, by weight; 5 percent fine crystals of other salts; moderately saline; strongly sodic; slight effervescence; moderately alkaline; clear smooth boundary.
Bkyz3--37 to 43 inches; reddish brown (5YR 5/4) silty clay, reddish brown (5YR 4/4) moist; weak medium prismatic structure; few faint bedding planes; very firm, extremely hard; few fine and very fine roots; few fine and very fine pores; 1 percent fine carbonate masses; 1 percent fine gypsum crystals, by volume; 2 percent gypsum, by weight; 5 percent fine crystals of other salts; moderately saline; strongly sodic; strong effervescence; moderately alkaline; clear smooth boundary.
Bkyz4--43 to 58 inches; reddish brown (5YR 5/3) silty clay, reddish brown (5YR 4/3) moist; weak medium prismatic structure; very firm, extremely hard; few fine and very fine roots; few fine and very fine pores; few fine iron-manganese masses; 1 percent fine carbonate masses; 1 percent fine gypsum crystals, by volume; 2 percent gypsum, by weight; 10 percent fine crystals of other salts; moderately saline; strongly sodic; slight effervescence; moderately alkaline; gradual smooth boundary.
Bkyz5--58 to 70 inches; reddish brown (5YR 5/3) silty clay, reddish brown (5YR 4/3) moist; weak medium prismatic structure parting to moderate medium angular blocky; very firm, extremely hard; few fine and very fine roots; few fine and very fine pores; few fine iron-manganese masses; 1 percent fine carbonate masses; 1 percent fine gypsum crystals, by volume; 3 percent gypsum, by weight; 3 percent fine crystals of other salts; moderately saline; strongly sodic; slight effervescence; moderately alkaline; gradual wavy boundary. (combined thickness of the Bkyz horizons : 20 to70 inches thick)
Bkssyz--70 to 80 inches; reddish brown (5YR 5/3) silty clay, reddish brown (5YR 4/3) moist; weak coarse angular blocky structure parting to weak medium angular blocky; very firm, extremely hard; few fine and very fine roots; few fine and very fine pores; 5 percent distinct slickensides; few fine iron-manganese masses; 1 percent fine carbonate masses; 1 percent fine gypsum crystals, by volume; 2 percent gypsum, by weight; 2 percent fine crystals of other salts; moderately saline; strongly sodic; slight effervescence; moderately alkaline.
TYPE LOCATION: Greer County, Oklahoma; From the intersection of U.S. Highway 283 and OK State Highway 34 in Mangum, about 16 miles north on U.S. Highway 283, 11 miles west and 0.6 miles north on county roads, located about 400 feet east in rangeland; about 2100 feet south and 400 feet east of the northwest corner of Section 1, Township 7N, Range 24W; Latitude: 35 degrees, 06 minutes, 38.78 seconds N; Longitude: 99 degrees, 41 minutes, 34.84 seconds W. Plainview, OK topographic quadrangle; NAD 1927.
RANGE IN CHARACTERISTICS:
Particle-size control section (weighted average)
Clay content: 35 to 60 percent
CEC/clay ratio: 0.24 to 0.40
Depth to secondary calcium carbonate: 0 to 20 inches
Depth to a gypsic horizon: 10 to 35 inches
Buried horizons occur in some pedons but they are not diagnostic for the series.
A Horizon
Hue: 2.5YR to 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 3 or 4; Where moist value and chroma are 3, thickness is less than 7 inches
Texture: silty clay loam, clay loam, or clay
Clay content: 30 to 60 percent
Coarse fragments: 0 to 5 percent; shale, dolomite, gypsum, and possibly a few siliceous gravels
Calcium carbonate equivalent: 0 to 10 percent
EC (dS/m): 0 to 8
Gypsum: 0 to 5 percent by weight
SAR: 0 to 8
Effervescence: noneffervescent to strongly effervescent
Reaction: Moderately alkaline or strongly alkaline (pH 7.9 9.0)
Bw Horizon (where present)
Hue: 2.5YR to 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 4 to 6
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 60 percent
Coarse fragments: 0 to 10 percent; shale, dolomite, gypsum, and possibly a few siliceous gravels
Calcium carbonate equivalent: 0 to 10 percent
EC (dS/m): 0 to 4
Gypsum: 0 to 2 percent by weight
SAR: 0 to 8
Effervescence: noneffervescent to strongly effervescent
Reaction: Moderately alkaline or strongly alkaline (pH 7.9 9.0)
Bkyz and Bkssyz Horizons
Hue: 2.5YR to 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 4 to 6
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 60 percent
Coarse fragments: 0 to 15 percent; shale, dolomite, gypsum, and possibly a few siliceous gravels
Calcium carbonate equivalent: 2 to 15 percent
EC (dS/m): 2 to 16
Gypsum: 2 to 15 percent by weight by weight
SAR: 1 to 30
Effervescence: very slightly effervescent to violently effervescent
Reaction: Moderately alkaline or strongly alkaline (pH 7.9 9.0)
BC horizon, where present.
Hue: 2.5YR to 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 4 to 6
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 60 percent
Coarse fragments: 0 to 15 percent; shale, dolomite, gypsum, and possibly a few siliceous gravels
Calcium carbonate equivalent: 2 to 15 percent
EC (dS/m): 2 to 16
Gypsum: 2 to 15 percent by weight by weight
SAR: 1 to 30
Effervescence: very slightly effervescent to violently effervescent
Reaction: Moderately alkaline or strongly alkaline (pH 7.9 9.0)
C Horizon, where present.
Hue: 2.5YR to 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 4 to 6
Texture: clay loam, silty clay loam, silty clay, or clay; Bedding planes and thin strata of coarser material are weakly to strongly expressed.
Clay content: 27 to 60 percent
Coarse fragments: 1 to 15 percent; shale, dolomite, gypsum, and possibly a few siliceous gravels
Calcium carbonate equivalent: 2 to 15 percent
EC (dS/m): 4 to 16
Gypsum: 2 to 15 percent by weight
SAR: 3 to 30
Effervescence: very slightly effervescent to violently effervescent
Reaction: Moderately alkaline or strongly alkaline (pH 7.9 9.0)
COMPETING SERIES: There are no series in the same family. Similar soils are the Mangum, Owens, Tilvern, Throck, Vernon, and Yellowhouse series.
Owens, Vernon, and Yellowhouse series: These soils are less than 40 inches deep to bedrock. In addition, Owens soils have hues of 7.5YR to 5Y in the solum and Yellowhouse soils occur in a drier climate.
Tilvern and Throck series: These soils are less than 60 inches deep to bedrock and have vertic properties.
Mangum series: These soils occur on flood plains and have vertic properties.
GEOGRAPHIC SETTING:
Parent material: recent calcareous, gypsiferous, and saline clayey slope alluvium derived from Permian age redbed shale and claystone
Landform: toe slopes and alluvial fans on pediments below areas of raw outcrops or escarpments of Permian age redbeds.
Slope: 0 to 3 percent
Mean annual air temperature range: 57 to 64 degrees F.
Mean annual precipitation range: 22 to 30 inches
Frost-free period: 185 to 230 days
Elevation: 1000 to 2000 feet
Thornthwaite annual P-E indices: 32 to 44
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beckman, Clairemont, Hayfork, Knoco, Mangum, Nipsum, Spur, and Vernon series.
Beckman, Hayfork, and Mangum series: These soils occur on slightly lower flood plains.
Clairemont and Spur series: These soils occur on lower flood plains and contain less than 35 percent clay content in the particle-size control section.
Knoco and Vernon series: These soils occur on higher areas and have bedrock within 40 inches of the surface.
Nipsum series: These soils occur on similar areas, but have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is very slow. Runoff is high on 0 to 1 percent slopes and very high on 1 to 3 percent slopes. The soil is rarely moistened to below 20 inches. These soils have none to frequent overland flow for very brief periods from April to October.
USE AND VEGETATION: Used mainly as grazing land for beef cattle. The native vegetation is a sparse cover of short grasses, prickly pear cactus, and various thorny shrubs such as mesquite and lote bush.
DISTRIBUTION AND EXTENT: Central rolling red plains of Oklahoma and Texas; LRR H; MLRAs Central Rolling Red Plains, Western Part (78B) andCentral Rolling Red Plains, Eastern Part (78C); Moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jackson County, Oklahoma; 1956.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 10 to 40 inches. (A2, Bkyz1, Bkyz2, & Bkyz3 horizons)
Ochric epipedon: 0 to 13 inches. (A1 & A2 horizons)
Gypsic horizon: 13 to 24 inches. (Bkyz1 horizon)
Cambic horizon: 24 to 80 inches. (Bkyz2, 3, 4, 5, and Bkssyz horizons)
Other features:
Additional Comments:
These soils were formerly classified in the alluvial soil great group.
The assignment of the cation-exchange activity class is supported by laboratory data number S00OK-055-003 from Greer County, OK.
Range Site: Clay Flats PE 34-44 R078CY064OK
Clay Flat PE 25-36 078BY071TX
Soil Interpretation Record Number: Series OK0148; Nonflooded OK0351
Taxonomic version: Keys to Soil Taxonomy, Ninth Edition, 2003
ADDITIONAL DATA: NSSL data from the type location in Greer Co., OK; Sample # S00OK-055-003