LOCATION BEAVERFLAT MTEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Beaverflat loam, cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 7 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak coarse platy structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; slightly acid (pH 6.4); clear smooth boundary. (4 to 7 inches thick)
Bt1--7 to 15 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate coarse and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; common faint clay films on faces of peds and in pores; slightly acid (pH 6.4); clear wavy boundary.
Bt2--15 to 30 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong fine and medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine and few fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds and in pores; neutral (pH 6.8); gradual wavy boundary. (Combined thickness of the Bt horizon is 14 to 27 inches.)
BC--30 to 34 inches; pale brown (10YR 6/3) sandy clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; very hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; neutral (pH 6.8); abrupt wavy boundary. (0 to 12 inches thick)
2C--34 to 60 inches; variegated colored sand; single grain; loose, nonsticky and nonplastic; 10 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Carter County, Montana; 50 feet west and 1,300 feet south of the NE corner of sec. 27, T. 2 N., R. 56 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches; dry in some part for six tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is higher than 41 degrees F.
Mollic epipedon thickness - 10 to 16 inches
Depth to 2C horizon - 20 to 40 inches, but mainly 28 to 36 inches.
Ap horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: loam or sandy loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 5.6 to 6.5
Bt horizons - Hue: 10YR or 2.5Y
Value: 4, 5, or 6 dry; 3 or 4 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam, sandy clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.1 to 7.3
BC horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: loam or sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.3
2C horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 3 or 4
Texture: sand or loamy sand
Clay content: 0 to 5 percent
Rock fragments: 0 to 35 percent pebbles, but mainly less than 15 percent
Reaction: pH 6.6 to 7.3
COMPETING SERIES:
Attewan (MT) - have a Bk horizon above the 2C horizon; have more than 35 percent coarse fragments in the 2C horizon.
Degrand (MT) - have a Bk horizon above the 2C horizon.
GEOGRAPHIC SETTING:
Landform - alluvial fans; relict stream terraces.
Elevation - 3,000 to 3,800 feet.
Slope- 0 to 4 percent.
Parent material - alluvium that is 20 to 40 inches deep over sand or loamy sand.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual temperature - 41 to 45 degrees F.
Frost-free period - 110 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the A and B horizons and rapid permeability in the 2C horizon.
USE AND VEGETATION: Beaverflat soils are used mainly for nonirrigated crops. Potential native vegetation in uncultivated areas is mainly western wheatgrass, needleandthread, prairie sandreed, bluebunch wheatgrass, blue grama, little bluestem, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Beaverflat soils are not extensive in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Carter County, Montana, 1992.
REMARKS: Soil interpretations record: MT1136. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 0 to 15 inches (Ap and Bt1 horizons); an argillic horizon from 7 to 30 inches (Bt1 and Bt2 horizons); and a particle-size control section from 7 to 40 inches (Bt1, Bt2, BC, and 2C horizons). Beaverflat soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.