LOCATION CARDWELL MTEstablished Series
TAXONOMIC CLASS: Fine-silty over sandy or sandy-skeletal, mixed, superactive, frigid Oxyaquic Haplustolls
TYPICAL PEDON: Cardwell silty clay loam, in pasture (colors are for dry soil unless otherwise noted).
A1--0 to 6 inches; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine and common fine roots; many very fine and common fine pores; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary.
A2--6 to 14 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine and few fine pores; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (Combined thickness of A horizons is 10 to 15 inches).
Bw--14 to 28 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; common fine distinct strong brown (7.5YR 4/6) redox concentrations; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and few fine pores; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 25 inches thick)
2C1--28 to 36 inches; light brownish gray (10YR 6/2) very gravelly loamy sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; 45 percent pebbles; slightly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 10 inches thick)
2C2--36 to 60 inches; pale brown (10YR 6/3) very gravelly loamy sand, brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; 50 percent pebbles; moderately alkaline (pH 8.0).
TYPE LOCATION: Jefferson County, Montana; 60 feet east and 230 feet south of the NW corner of sec. 15, T. 1 N., R. 4 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 10 to 15 inches.
Depth to 2C horizon - 20 to 40 inches.
Depth to seasonal high water table - 24 to 42 inches for extended periods during spring and early summer.
A horizons - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: silty clay loam, loam, or sandy loam with thin strata of clay loam, silt loam or very fine sandy loam.
Clay content: 10 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Calcium carbonate equivalent: 0 to 10 percent
Electrical conductivity: 0 to 4 mmhos/cm (saline phase 4 to 16 mmhos/cm)
SAR: 0 to 8 (saline phase)
Reaction: pH 7.4 to 8.4
Bw horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: loam or silt loam with thin strata of clay loam, silty clay loam or very fine sandy loam.
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent pebbles
Calcium carbonate equivalent: 0 to 10 percent
Electrical conductivity: 0 to 4 mmhos/cm (saline phase 4 to 16 mmhos/cm)
SAR: 0 to 8 (saline phase)
Reaction: pH 7.4 to 8.4
This horizon contains greater than 15 percent fine sand or coarser material.
2C horizons - Hue: 10YR, 2.5Y or 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3 or 4
Texture: loamy sand or sand and may have strata of fine sandy loam, loam or very fine sandy loam.
Clay content: 0 to 10 percent
Rock fragments: 35 to 75 percent--0 to 15 percent cobbles, 35 to 60 percent pebbles
Calcium carbonate equivalent: 0 to 5 percent
Electrical conductivity: 0 to 8 mmhos/cm (saline phase 2 to 8 mmhos/cm)
Reaction: pH 6.6 to 8.4
COMPETING SERIES:
There are no competing series.
GEOGRAPHIC SETTING:
Landform - floodplains and floodplain steps.
Elevation - 3,800 to 5,000 feet.
Slope- 0 to 2 percent.
Parent material - recent alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 40 to 44 degrees F.
Frost-free period - 90 to 115 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderate permeability above the 2C horizon and rapid permeability in the 2C horizon.
USE AND VEGETATION: These soils are primarily used for irrigated and nonirrigated cropland, for hay and pasture and for rangeland. The potential native vegetation is mainly western wheatgrass, thickspike wheatgrass, green needlegrass, Sandberg bluegrass, basin wildrye, woods rose and snowberry. Groves of cottonwood trees, Rocky Mountain Juniper and willows occur in some areas.
DISTRIBUTION AND EXTENT: The Cardwell series is of moderate extent in the intermountain valleys of southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretations records: MT1003, MT1649. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 14 inches (A1 and A2 horizons); a cambic horizon from 14 to 20 inches (Bw horizon); a particle-size control section from 10 to 40 inches (A2, Bw, 2C1 and 2C2 horizons). Cardwell soils have a frigid temperature regime and an ustic, bordering on aquic moisture regime.