LOCATION SUDDUTH CO+IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic Vertic Argicryolls
TYPICAL PEDON: Sudduth loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; strong fine granular structure; soft, very friable; neutral (pH 6.6); clear smooth boundary. (3 to 6 inches thick)
BA--4 to 7 inches; dark grayish brown (10YR 4/2) light clay loam, very dark brown (10YR 2/2) moist; weak prismatic structure parting to strong fine subangular blocks; slightly hard, very friable, slightly sticky and slightly plastic; peds are hard; few thin glossy patches on faces of peds and in root channels; neutral (pH 6.6); clear smooth boundary. (3 to 4 inches thick)
Bt--7 to 20 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong fine prismatic structure parting to strong fine subangular blocks; slightly hard, very friable, slightly sticky and slightly plastic; peds are very hard; many wax-like patches on faces of peds and wax-like coatings on the inside of root channels and pores; wax-like rims around the entrance to some soil pores; neutral (pH 6.6); abrupt smooth boundary. (5 to 14 inches thick)
2B/E--20 to 23 inches; mixed colors including light brownish gray (2.5Y 6/2) and pale yellow (2.5Y 8/2) light clay, grayish brown (2.5Y 5/2) and light gray (2.5Y 7/2) moist; strong fine angular blocky structure; slightly hard; this horizon consists primarily of clayey aggregates like the underlying horizon that are embedded in a lighter colored and coarser textured matrix; thin nearly continuous glossy patches on the more clayey peds; 5 to 10 percent gravel forming a stone line; few fine distinct olive brown (2.5Y 4/4) moist iron concentrations; slightly acid (pH 6.4); clear smooth boundary. (2 to 6 inches thick)
2Bt--23 to 30 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; strong fine and medium angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; peds are extremely hard; wide cracks between peds when dry; thin nearly continuous wax-like coatings on faces of peds and thin wax-like coatings on the inside of root channels; few glossy slickenside surfaces; neutral (pH 6.6); gradual wavy boundary. (5 to 14 inches thick)
2BC--30 to 34 inches; light olive brown (2.5Y 5/3) clay, olive brown (2.5Y 4/3) moist; weak medium and coarse angular blocky structure; wide cracks between peds when dry; slightly hard, friable, moderately sticky and moderately plastic; peds are extremely hard; few thin glossy slickensides; neutral (pH 6.6); gradual wavy boundary. (2 to 5 inches thick)
2C--34 to 60 inches; light olive brown (2.5Y 5/3) clay, olive brown (2.5Y 4/3) moist; massive; extremely hard, very firm, moderately sticky and moderately plastic; irregular cracks divide this horizon when dry; neutral (pH 6.6).
TYPE LOCATION: Jackson County, Colorado; 600 feet east and 650 feet south of the center of Sec. 13, T. 5 N., R. 82 W.
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic. These soils are dry in some part of the moisture control section for some time in most years and are moist in the spring and early summer.
Mean annual soil temperature: 36 to 40 degrees F.
Mean summer soil temperature 54 to 58 degrees F.
Depth to uniformly calcareous material: 40 to more than 60 inches.
Depth to the base of the argillic horizon: 20 to 50 inches.
Thickness of the mollic epipedon: 16 to 50 inches.
Vertic features: Wide cracks develop in the lower part of the argillic horizon and in the C horizon when dry but do not extend to the surface or to the base of any A horizon. COLE ranges from above .03 to .13 between individual subhorizons with COLE increasing with depth. Average Linear Extensibility is estimated to range from 6.0 to 7.5 from the surface to a depth of 40 inches.
Particle size control section:
Clay content: 35 to 60 percent
Rock fragment content: 0 to 35 percent
A lithologic discontinuity separates the upper and lower parts of the Bt horizon or occurs between the solum and C horizon and in addition to an increase in clay content is usually marked by a thin weak E horizon, or a thin horizon in which bleaching of sand and silt grains on faces of peds is pronounced or by a distinct stone line. A majority of the subhorizons above a depth of 50 inches have hue of 7.5YR or yellower. Some pedons have few faint redox features with chroma of more than 2 in both matrix and redox features, and some pedons have common distinct redox features with low chroma in the horizons adjacent to the litholigic discontinuity.
A horizon
Hue: 5Y to 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry and moist.
Reaction: moderately acid to slightly alkaline.
Bt horizon:
Hue: 5Y to 7.5YR
Value: 5 to 7 dry, 3 through 6 moist
Chroma: 1 to 6, dry and moist.
Texture, fine earth fraction: loam or clay loam in the upper part increasing to clay in the lower part and averages 35 to 60 percent clay, 5 to 45 percent silt, and 15 to 55 percent sand with more than 15 percent being fine or coarser sand.
Rock fragment content: 0 to 35 percent
Reaction: moderately acid to slightly alkaline.
2C horizon:
Hue: 5Y to 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 1 to 4, dry and moist.
Texture, fine earth fraction: clay or clay loam to depths of at least 50 inches.
Rock fragment content: 0 to 35 percent
Reaction: moderately acid to slightly alkaline in the upper part that increases in alkalinity with increasing depth in some pedons.
COMPETING SERIES: These are the Cimarron, Cucharas, Gourley, Heathcoat, Wetopa, and Youman series.
Cimarron: do not have a lithologic discontinuity.
Cucharas: have a paralithic contact at 20 to 40 inches.
Gourley: have horizons of calcium carbonate accumulation.
Heathcoat: have horizons of calcium carbonate accumulation.
Wetopa: do not have a lithologic discontinuity.
Youman: do not have a lithologic discontinuity.
GEOGRAPHIC SETTING:
Parent material: polylithologic materials derived from sedimentary rocks and consisting of a fine textured lower section overlain by coarser textured material.
Landform: alluvial fans and concave drainageways.
Slopes: 0 to 20 percent.
Elevation: 8,600 to 9,500 feet, 3,800 to 4,200 feet in Idaho
Mean annual air temperature: 34 to 40 degrees F., and mean summer air temperature ranges from 52 to 56 degrees F.
Mean annual precipitation: about 18 inches at the type location, with peak periods of precipitation during the spring and early summer; in Idaho they receive up to 25 inches
Wettest months: Spring and early summer
Driest months:
Frost-free period: 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gothic and Leavitt soils. Gothic soils have mollic epipedons less than 16 inches thick, lack a lithologic discontinuity within the Bt horizon, and lack any E or B/E horizons. Leavitt soils have continuous horizons of carbonate accumulation, have mollic epipedons less than 16 inches thick, and lack any E or B/E horizons.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderate runoff; slow permeability. Perched water tables develop above the fine textured lower particle size control section of these soils in spring seasons.
USE AND VEGETATION: These soils are used principally for livestock grazing or they may be occasionally used as native hay meadow. Native vegetation consists of Idaho fescue and Letterman's needlegrass.
DISTRIBUTION AND EXTENT: High mountain valleys of north-central Colorado, and central Idaho. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jackson County Area, Colorado; 1973.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 20 inches. (A, BA, and Bt horizons)
Argillic horizon: The zone from 7 to 20 inches. (Bt horizon)
Vertic feature: Slickensides and cracks in the 2Bt and 2BC horizons.
Episaturation: The zone of saturation at 20 to 23 inches in some seasons. (2B/E horizon)
Lithologic discontinuity: At the upper boundary of the 2B/E horizon.
Particle size control section: The zone from 7 to 20 inches. (Bt horizon)
Keys To Soil Taxonomy: Classified according to the Eighth Edition, 1998