LOCATION VANSTEL MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aridic Haplustalfs
TYPICAL PEDON: Vanstel loam, in grassland. (Colors are for dry soil unless otherwise noted)
A--0 to 5 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; weak fine platy structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; slightly alkaline (pH 7.4); clear smooth boundary. (3 to 7 inches thick)
Bt1--5 to 11 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong medium prismatic structure parting to strong angular blocky; hard, friable, sticky and plastic; many fine roots; many very fine tubular pores; continuous distinct clay films on faces of peds; slightly alkaline (pH 7.4); clear smooth boundary.
Bt2--11 to 18 inches; pale brown (10YR 6/3) loam, dark grayish brown (10YR 4/2) moist; strong medium prismatic structure parting to strong medium angular blocky; slightly hard, friable, slightly sticky and plastic; common fine roots; many very fine tubular pores; continuous faint clay films on faces of peds; slightly alkaline (pH 7.4); gradual smooth boundary. (Combined Bt horizons 7 to 14 inches thick)
Btk--18 to 24 inches; light gray (10YR 7/2) loam, grayish brown (2.5Y 5/2) moist; moderate medium and coarse prismatic structure parting to moderate medium and coarse angular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine tubular pores; common faint clay films on faces of peds; common fine masses of lime; disseminated lime; strongly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (4 to 8 inches thick)
BC1--24 to 35 inches; light gray (10YR 7/2) loam, grayish brown (2.5Y 5/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; strongly effervescent; moderately alkaline (pH 8.2); gradual smooth boundary. (0 to 17 inches thick)
BC2--35 to 60 inches; very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; massive slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Rosebud County, Montana; 1,300 feet north and 2,300 feet east of SW corner of sec. 5, T. 5 N., R. 40 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 47 degrees F.
Moisture control section - between 4 and 12 inches, dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to carbonates - 10 to 21 inches.
Percent rock fragments - 0 to 5
A horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: loam or silt loam
Clay content: 14 to 25 percent
Reaction: pH 6.6 to 7.8
Bt horizons - Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: loam, silt loam, clay loam or silty clay loam
Clay content: 25 to 35 percent, with less than 15 percent sand coarser than very fine sand
Reaction: pH 6.6 to 7.8
Btk or Bk horizon - Hue: 10YR or 2.5Y
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 2 or 3
Texture: loam, silt loam, clay loam or silty clay loam
Clay content: 18 to 35 percent
Calcium carbonate equivalent: 3 to 15 percent
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 7.9 to 9.0
BC horizons - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 to 6 moist
Chroma: 2 to 4
Texture: loam, silt loam, clay loam or silty clay loam
Clay content: 18 to 30 percent
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Davidell (MT) - has an SAR greater than 8; has horizons of accumulation of gypsum and other salts above a depth of 60 inches.
Debs (MN) - has a moisture control section that is moist in all parts more than five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Ivanell (MT) - has a paralithic contact of semiconsolidated shale or semiconsolidated shale and siltstone.
Virkula (SD) - is noncalcareous throughout the profile.
Winterridge (UT) - has hue of 7.5YR or redder in the argillic horizon.
GEOGRAPHIC SETTING:
Landform - alluvial fans; fan remnants; stream terraces; sedimentary plains.
Elevation - 2,200 to 5,500 feet.
Slope- 0 to 15 percent.
Parent material - alluvium or colluvium from semiconsolidated shale, siltstone, and sandstone.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 16 inches.
Mean annual temperature - 38 to 45 degrees F.
Frost-free period - 100 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Vanstel soils are used for nonirrigated small grains and for rangeland. The potential native vegetation is bluebunch wheatgrass, western wheatgrass, green needlegrass, needleandthread, forbs, and shrubs.
DISTRIBUTION AND EXTENT: The Vanstel series is of moderate extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Rosebud County, Montana, 1985.
REMARKS: Soil interpretation records: MT0588. Diagnostic horizon and features recognized in this pedon are: an ochric epipedon from the soil surface to a depth of 7 inches (A, Bt1 horizons); an argillic horizon, which is also the particle-size control section, from 5 to 18 inches (Bt1, Bt2 horizons); accumulation of lime from 18 to 24 inches (Btk horizon). Vanstel soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.
ADDITIONAL DATA: Lab samples 78P0490-492; S77MT-087-019.