LOCATION RICHEY MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Torrertic Haplustolls
TYPICAL PEDON: Richey silty clay loam, cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 7 inches; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and very fine granular structure; hard, friable, sticky and plastic; many fine and very fine roots; many fine and very fine pores; slightly effervescent; slightly alkaline (pH 7.7); abrupt smooth boundary. (7 to 9 inches thick)
Bw--7 to 13 inches; grayish brown (10YR 5/2) silty clay loam, dark grayish brown (10YR 4/2) moist; very dark grayish brown (10YR 3/2) organic staining on faces of peds; moderate medium prismatic structure parting to moderate fine subangular blocky; hard, friable, sticky and plastic; many fine and very fine and few medium roots; many fine and few medium pores; strongly effervescent; moderately alkaline (pH 7.9); gradual wavy boundary. (6 to 12 inches thick)
Bk1--13 to 20 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to moderate medium blocky; very hard, friable, sticky and plastic; many fine and very fine roots; many fine and very fine pores; few fine threads and masses of lime; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (2 to 8 inches thick)
Bk2--20 to 29 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; very hard, friable, sticky and plastic; common fine and very fine roots; many fine and very fine pores; common fine soft masses of segregated lime; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (4 to 12 inches thick)
Byz1--29 to 46 inches; light brownish gray (2.5Y 6/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure; extremely hard, firm, sticky and plastic; many fine and very fine roots; many fine and very fine pores; common masses of gypsum and other salts; slightly effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (0 to 18 inches thick)
Byz2--46 to 68 inches; light brownish gray (2.5Y 6/2) silty clay loam with thin strata of silt loam and loam, dark grayish brown (2.5Y 4/2) moist; massive; extremely hard, firm, sticky and plastic; common fine and very fine pores; few fine threads and masses of gypsum and other salts; slightly effervescent; strongly alkaline (pH 8.7).
TYPE LOCATION: Fergus County, Montana; 660 feet west and 2,000 feet south of the NE corner of sec. 15, T. 15 N., R. 23 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 12 inches.
Depth to Bk horizon - 12 to 20 inches.
Ap horizon - Hue: 10YR or 2.5Y
Chroma: 2 or 3
Texture: clay loam, silty clay loam, silty clay or clay
Clay content: 27 to 50 percent
Rock fragments: 0 to 5 percent pebbles
Reaction: pH 6.6 to 7.8
Bw horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3, 4 or 5 moist
Chroma: 2 or 3
Texture: silty clay loam or silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 5 percent pebbles
Reaction: pH 7.9 to 9.0
Bk horizons - Hue: 10YR or 2.5Y
Value: 5 or 6 dry;
Chroma: 2 or 3
Texture: silty clay loam or silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 5 percent pebbles
Calcium Carbonate Equivalent: 5 to 15 percent
Reaction: pH 7.9 to 9.0
Bky and Byz horizons - Hue: 10YR or 2.5Y
Value: 5, 6 or 7 dry
Chroma: 2 or 3
Texture: silty clay loam, clay loam, or silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 5 percent pebbles
EC: 0 to 16 mmhos/cm
Calcium carbonate equivalent: 2 to 10 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Bilhil (CO) - is moderately well drained; has a frost-free period of less than 95 days; occurs at elevations of more than 6,000 feet; has redoximorphic features at less than 50 inches; and does not have gypsum or other salts above a depth of 30 inches.
GEOGRAPHIC SETTING:
Landform - stream terraces and alluvial fans.
Elevation - 2,000 to 5,200 feet.
Slope- 0 to 8 percent.
Parent material - clayey alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 95 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow or slow permeability.
USE AND VEGETATION: Richey soils are used mainly for dryland and irrigated cropland, pasture, and rangeland. Potential native vegetation is mainly western wheatgrass, green needlegrass, bluebunch wheatgrass, blue grama, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Richey soils are of small extent in central and eastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Fergus County, Montana, 1979.
REMARKS: Soil Interpretations Records: MT0355 and MT0701. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 7 inches (Ap horizon; a cambic horizon from 7 to 13 inches (Bw horizon); horizons of secondary carbonate accumulation from 13 to 29 inches (Bk horizons); horizons of gypsum and salt accumulation from 29 to 68 inches (Byz horizons); a particle-size control section from 10 to 40 inches (Bw, Bk1, Bk2, Byz1 horizons). Richey soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.