LOCATION BEMISHAVE MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, frigid Vitrandic Haploxeralfs
TYPICAL PEDON: Bemishave loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 5 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine, and few fine, medium, and coarse roots; volcanic ash component; neutral (pH 7.0); clear smooth boundary. (3 to 7 inches thick)
E/Bt--5 to 13 inches; E part (60 percent) is light gray (10YR 7/2) loam, brown (10YR 5/3) moist; Bt part (40 percent) is very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; moderate coarse subangular blocky structure; hard, firm, sticky and plastic; common very fine, few fine, medium, and coarse roots; few faint clay films on faces of peds; volcanic ash component; slightly acid (pH 6.2); clear smooth boundary. (0 to 10 inches thick)
Bt--13 to 25 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; strong medium subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; many distinct clay films on faces of peds; slightly acid (pH 6.2); clear smooth boundary. (10 to 25 inches thick)
C--25 to 60 inches; light reddish brown (5YR 6/3) clay, reddish brown (5YR 5/3) moist; massive; 1/16- to 1/4-inch thick varves of clay; hard, firm, very sticky and very plastic; neutral (pH 7.2).
TYPE LOCATION: Sanders County, Montana; 2,500 feet east and 400 feet north of the SW corner of sec. 18, T. 20 N., R. 26 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Some pedons have a 1/2- to 1-inch duff of forest litter over the A horizon.
The surface horizon, when mixed to a depth of 7 inches does not meet the thickness requirements of a mollic epipedon.
Ap horizon - Value: 5, 6, or 7 dry; 3, 4, or 5 moist
Chroma: 2 or 3
Clay content: 10 to 25 percent
Bulk density: 1.0 to 1.4 g/cc
Acid oxalate extraction (Al + 1/2 Fe): .4 to 1.2 percent
Reaction: pH 6.1 to 7.3
E/Bt horizon - Value: E part 6 or 7, Bt part 6 or 7 dry; E part 5 or 6, Bt part 4 or 5 moist
Chroma: E and Bt parts 2 or 3
Texture: E part silt loam or loam, Bt part loam, silty clay loam, silty clay, or clay
Clay content: E part 10 to 25 percent, Bt part 25 to 60 percent
Bulk density: 1.0 to 1.4 g/cc
Acid oxalate extraction (Al + 1/2 Fe): .4 to 1.2 percent
Reaction: pH 6.1 to 7.3
Bt horizon - Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: silty clay or clay
Clay content: 40 to 60 percent
Reaction: pH 6.1 to 7.3
C horizon - Value: 6 or 7 dry, 5 or 6 moist
Chroma: 2 or 3
Texture: silty clay, clay, or silty clay loam
Clay content: 35 to 60
Varves: 1/16- to 1/2-inch thick
Reaction: pH 6.6 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landforms - stream terraces.
Elevations - 2,400 to 2,800 feet.
Slope- 0 to 4 percent.
Parent material - a high component of volcanic ash in the surface layers and formed in lacustrine deposits.
Climate - long, cold winters; moist springs; warm, dry summers.
Mean annual precipitation - 15 to 19 inches, much of which falls as snow and spring rain.
Mean annual air temperature - 42 to 45 degrees F.
Frost-free period - 105 to 125 days.
DRAINAGE AND PERMEABILITY: Well drained; very slow permeability.
USE AND VEGETATION: Bemishave soils are used for timber production and cropland. The native vegetation is coniferous forest consisting of ponderosa pine with an understory of common snowberry, pinegrass and Idaho fescue.
DISTRIBUTION AND EXTENT: Bemishave soils are of small extent in western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Sanders County, Montana, 1997.
REMARKS: Soil interpretation record: MT1291. Diagnostic horizons and features recognized in this pedon are: an ash influenced layer from the soil surface to 13 inches (Ap, E/Bt horizons); an ochric epipedon from the soil surface to 13 inches (Ap and E/Bt horizons); an argillic horizon from 13 to 25 inches (Bt horizon); and a particle-size control section from 13 to 25 inches (Bt horizon). Bemishave soils have a frigid temperature regime and a xeric moisture regime.
ADDITIONAL DATA: Laboratory data S91MT-089-002.