LOCATION HAYFORK OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Pachic Haplustolls
TYPICAL PEDON: Hayfork silt loam -- in rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 4 inches; brown (7.5YR 5/2) silt loam, dark brown (7.5YR 3/2) moist; moderate fine subangular blocky structure parting to moderate fine and medium granular; friable, hard; many fine and very fine, and common medium roots; many fine and very fine, and common medium pores; noneffervescent; slightly acid; clear smooth boundary.
A2--4 to 11 inches; brown (7.5YR 4/2) silty clay, dark brown (7.5YR 3/2) moist; moderate medium prismatic structure parting to strong medium subangular blocky; firm, very hard; many fine and very fine roots between peds and common fine and very fine roots in the soil matrix; many fine and very fine, and common medium pores; noneffervescent; neutral; gradual smooth boundary. (Combined thickness of the A horizons ranges from 6 to 11 inches thick)
Bk--11 to 27 inches; reddish brown (5YR 4/3) silty clay, dark reddish brown (5YR 3/3) moist; moderate coarse prismatic structure parting to strong medium angular blocky; firm, very hard; many fine and very fine roots between peds and few very fine roots in the soil matrix; common fine and very fine, and few medium pores; 10 percent distinct pressure faces; common fine and medium carbonate masses; strong effervescence; moderately alkaline; gradual smooth boundary. (Combined thickness of the Bk horizons ranges from 10 to 25 inches thick)
Bky1--27 to 41 inches; reddish brown (5YR 5/3) silty clay loam, reddish brown (5YR 4/3) moist; moderate coarse prismatic structure parting to moderate medium angular blocky; firm, very hard; common fine and very fine roots between peds; few fine gypsum crystals; common fine and medium carbonate masses; strong effervescence; moderately alkaline; clear smooth boundary.
Bky2--41 to 50 inches; reddish brown (5YR 5/4) silty clay loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; friable, hard; few fine and very fine roots; common fine and medium gypsum crystals; common fine and medium carbonate masses; strong effervescence; moderately alkaline; clear smooth boundary. (Combined thickness of the Bky horizons ranges from 15 to 50 inches thick)
Cyz--50 to 60 inches; 60 percent reddish brown (5YR 5/4) and 40 percent reddish brown (5YR 5/3) faintly stratified silty clay loam, 60 percent reddish brown (5YR 4/4) and 40 percent reddish brown (5YR 4/3) moist; massive; friable, hard; common fine gypsum and other salt crystals; strong effervescence; moderately alkaline.
TYPE LOCATION: Greer County, Oklahoma; From the intersection of U.S. Highway 283 and OK Highway 34 in Mangum; about 16 miles north, 8.75 miles west, and 60 feet north in rangeland; located about 60 feet north and 1340 feet east of the southwest corner of Section 5, Township 7 North, Range 23 West; Latitude: 35 degrees, 06 minutes, 08.82 seconds N; Longitude: 99 degrees, 39 minutes, 17.74 seconds W.; Plainview, Oklahoma topographic quadrangle; NAD 1927.
RANGE IN CHARACTERISTICS:
Particle-size control section (weighted average)
Clay content: 35 to 50 percent
CEC/clay ratio: 0.4 to 0.6
Depth to secondary calcium carbonate: 0 to 11 inches
Depth to gypsum or other salt accumulations: 10 to 30 inches
Thickness of the mollic epipedon, 20 to 40 inches
Vertic features: Some pedons have pressure faces or cracks less than 1 cm wide from the surface to a depth of about 30 inches
Some pedons have buried horizons below 50 inches.
A horizon
Hue: 5YR or 7.5YR
Value: 4 or 5 (3 moist)
Chroma: 2 or 3
Texture: silt loam, silty clay loam, or silty clay.
Clay content: 20 to 45 percent
Calcium carbonate equivalent: 0 to 5 percent
EC (dS/m): 0 to 2
SAR: 0 to 2
Effervescence: Noneffervescent to strongly effervescent
Reaction: Slightly acid to moderately alkaline (pH 6.1 - 8.4)
Bk horizon
Hue: 5YR or 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 3 or 4
Texture: Silty clay, silty clay loam, clay loam, or clay
Clay content: 35 to 50 percent
Calcium carbonate equivalent: 2 to 15 percent
Identifiable secondary carbonate: few to common films, threads, fine masses, and concretions
EC (dS/m): 0 to 4
Gypsum: 0 to 1 percent
SAR: 0 to 3
Effervescence: Slightly effervescent to violently effervescent
Reaction: Slightly alkaline or moderately alkaline (pH 7.4 - 8.4)
Bky horizon
Hue: 5YR or 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 3 or 4
Texture: Silty clay, silty clay loam, clay loam, or clay
Clay content: 27 to 50 percent
Calcium carbonate equivalent: 2 to 15 percent
Identifiable secondary carbonate: few to common films, threads, fine masses, and concretions
EC (dS/m): 2 to 16
Gypsum: 1 to 5 percent
SAR: 2 to 6
Effervescence: Slightly effervescent to violently effervescent
Reaction: Moderately alkaline (pH 7.9 - 8.4)
BC or C horizons
Hue: 5YR or 7.5YR
Value: 4 or 5 (3 or 4 moist)
Chroma: 3 to 6
Texture: Silty clay, silty clay loam, clay loam, or clay and may have strata of loam or silt loam
Clay content: 27 to 50 percent
Calcium carbonate equivalent: 2 to 15 percent
Identifiable secondary carbonate: few to common films, threads, fine masses, and concretions
EC (dS/m): 2 to 16
Gypsum: 1 to 5 percent
SAR: 2 to 6
Effervescence: Slightly effervescent to violently effervescent
Reaction: Moderately alkaline (pH 7.9 - 8.4)
COMPETING SERIES: There are no other series in the same family. Similar soils are the
Clearfork,
Miller,
Nipsum, and
Westfork series.
Clearfork soils: These soils have a fine-silty particle-size control section.
Miller soils: These soils have a mollic epipedon less than 20 inches thick and have vertic properties.
Nipsum soils: These soils do not flood.
Westfork soils: These soils are moist for longer periods and are noncalcareous above 28 inches.
GEOGRAPHIC SETTING:
Parent material: Holocene age alluvium derived from Permian age redbed sediments.
Landform: Flood plain
Slope: 0 to 1 percent
Mean annual air temperature range: 60 to 64 degrees F.
Mean annual precipitation range: 22 to 26 inches
Frost-free period: 205 to 230 days
Elevation: 1200 to 2000 feet
Thornthwaite annual P-E indices: 32 to 40
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Beckman,
Cottonwood,
Knoco,
Mangum,
Nipsum,
Talpa, and
Vernon series.
Beckman and Mangum soils: These soils occur on flood plains slightly lower in the landscape and have an ochric epipedon.
Cottonwood, Knoco, and Talpa soils: These soils occur on higher upland areas and are less than 20 inches to bedrock.
Nipsum soils: This soil occurs on slightly higher footslope positions that do not flood.
Vernon soils: This soil occurs on higher upland areas, is less than 40 inches to bedrock, and has an ochric epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is medium. This soil is rarely flooded for very brief periods.
USE AND VEGETATION: Used mostly for livestock grazing. Native vegetation consists of short and mid grasses. Western wheatgrass, vine mesquite, sideoats grama, blue grama, and buffalograss are the dominant species. Mesquite has invaded most areas. Some areas are used for cropland. Wheat and cotton are the main crops.
DISTRIBUTION AND EXTENT: Southwest Oklahoma and possibly north Texas; LRR H; MLRA 78B and C; Small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Greer County, Oklahoma, 2004. The name is coined from Haystack Creek that runs near the type location.
REMARKS: These soils were previously included with the Mangum series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 27 inches. (A1, A2, and Bk horizons)
Cambic horizon: 11 to 50 inches. (Bk and Bky horizons)
Particle-size control section: 10 to 40 inches. (Bk and Bky1 horizons)
The assignment of the cation-exchange activity class is supported by laboratory data number S00OK-055-006 from Greer County, Oklahoma.
Range Site: Clayey Bottomland (078CY094TX)
ADDITIONAL DATA: NSSL data from Greer County, OK (S00OK-055-006).
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006