LOCATION ASHBOUGH MT
Established Series
Rev. GFB-KTS-RJS
03/2011
ASHBOUGH SERIES
The Ashbough series consists of very deep, moderately well drained soils that formed in alluvium. These soils are on flood plains and stream terraces. Slopes are 0 to 4 percent. Mean annual precipitation is about 12 inches and mean annual air temperature is about 39 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Torrifluventic Haplustepts
TYPICAL PEDON: Ashbough silt loam, in pasture (colors are for dry soil unless otherwise noted).
A--0 to 4 inches; grayish brown (10YR 5/2) silt loam, dark grayish brown (10YR 4/2) moist; weak fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine, and medium roots; many very fine and few fine pores; disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 10 inches thick)
Bw--4 to 12 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine, fine, and medium roots; many very fine and fine tubular and interstitial pores; disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 25 inches thick)
C1--12 to 22 inches; pale brown (10YR 6/3) loam, including thin strata of very fine sandy loam and sandy loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, moderately sticky and slightly plastic; common very fine and fine roots; many very fine and few fine tubular and interstitial pores; disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
C2--22 to 43 inches; light yellowish brown (2.5Y 6/3) loam, including thin strata of very fine sandy loam and sandy loam, light olive brown (2.5Y 5/3) moist; massive; soft, very friable, slightly sticky and nonplastic; common very fine and fine roots; many very fine and few fine tubular and interstitial pores; disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (Combined thickness of C horizons is 10 to 35 inches.)
Cg1--43 to 51 inches; light gray (2.5Y 7/2) silt loam, including thin strata of loam and sandy loam, light brownish gray (2.5Y 6/2) moist; common medium distinct light yellowish brown (10YR 6/4) moist redox concentrations; massive; slightly hard, very friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and few fine tubular and interstitial pores; disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
Cg2--51 to 61 inches; light brownish gray (2.5Y 6/2) sandy loam, including thin strata of silt loam and loam, grayish brown (2.5Y 5/2) moist; common fine distinct light yellowish brown (10YR 6/4) moist redox concentrations; massive; soft, very friable, nonsticky and nonplastic; disseminated calcium carbonate; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (combined thickness of Cg horizons is 10 to 20 inches)
2C--61 to 84 inches; grayish brown (2.5Y 5/2) extremely gravelly sand, dark grayish brown (2.5Y 4/2) moist; single grain; loose, nonsticky and nonplastic; 70 percent gravel; slightly effervescent; moderately alkaline (pH 8.0)
TYPE LOCATION: Beaverhead County, Montana; 2400 feet north and 300 feet west of the SE corner of section 18, T. 7 S., R. 8 W. Dillon East topographic quadrangle. lat. 45 degrees 12 minutes 00 seconds N. and long. 112 degrees 37 minutes 30 seconds W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 42 to 46 degrees F.
Depth to lithologic discontinuity - 40 to greater than 60 inches
Depth to seasonal high water table - 42 to 60 inches
Soil phases - saline
Note: Some pedons may have an Oe horizon less than 3 inches thick.
A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Texture: loam or silt loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: 5 to 30 percent
Reaction: pH 6.6 to 8.4
Saline phase
EC: 4 to 8 mmhos/cm
Bw horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 7 dry; 3 to 5 moist
Chroma: 1 to 3; dry or moist
Texture: sandy loam, loam, silt loam or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: 10 to 30 percent
Reaction: pH 7.9 to 8.4
Saline phase
EC: 4 to 16 mmhos/cm
C horizons
Hue: 10YR, 2.5Y or 5Y; dry or moist
Value: 4 to 7 dry; 3 to 6 moist
Chroma: 1 to 4; dry or moist
Texture: sandy clay loam, loam, silt loam or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Calcium carbonate equivalent: 5 to 30 percent
Reaction: pH 7.9 to 8.4
Saline phase
2 to 16 mmhos/cm
Cg horizons
Hue: 10YR, 2.5Y or 5Y
Value: 6 to 8 dry; 5 to 7 moist
Chroma: 1 or 2; dry or moist
Texture: sandy loam, sandy clay loam, loam or silt loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 15 percent gravel
Electrical conductivity: less than 2 mmhos/cm
Calcium carbonate equivalent: 5 to 30 percent
Reaction: pH 7.4 to 8.4
2C horizon
Hue: 2.5Y or 5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 1 or 2; dry or moist
Texture: loamy sand, loamy coarse sand, sand, or coarse sand
Clay content: 0 to 10 percent
Rock fragments: 35 to 80 percent--35 to 70 percent gravel, 0 to 15 percent cobbles
Calcium carbonate equivalent: 0 to 15 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - flood plains and stream terraces
Elevation - 4,500 to 6,500 feet
Slope - 0 to 4 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 10 to 14 inches
Mean annual air temperature - 36 to 43 degrees F.
Frost-free period - 70 to 105 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Moderately well drained, moderate permeability above the 2C horizon and rapid permeability in the 2C horizon.
USE AND VEGETATION: Ashbough soils are primarily used for rangeland, pasture, and cropland. The potential native vegetation is mainly Western wheatgrass, needleandthread, basin wildrye, prairie junegrass, iris and sedges.
DISTRIBUTION AND EXTENT: Ashbough soils are of small extent in southwestern Montana. MLRA 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Beaverhead County, Montana, 2001. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 4 inches ( A horizon)
Cambic horizon - from 4 to 12 inches (Bw horizon)
An irregular decrease of carbon with depth
Particle-size control section - from 10 to 40 inches (part of Bw, C1 and part of C2 horizons)
Ashbough soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
National Cooperative Soil Survey
U.S.A.