LOCATION KRAUSE             MT 
Established Series
REV. TJW-CRS-JAL
11/1999

KRAUSE SERIES


The Krause series consists of very deep, excessively drained soils that formed in volcanic ash over alluvium. Krause soils are on stream terraces, escarpments and alluvial fans. Slopes are 0 to 60 percent. Mean annual precipitation is about 18 inches, and mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Andic Haplustepts

TYPICAL PEDON: Krause gravelly ashy silt loam, forested. (colors are for dry soil unless otherwise noted).

Oi--0 to 1 inch; undecomposed and slightly decomposed forest litter. (1 to 2 inches thick)

A--1 to 3 inches; brown (10YR 5/3) gravelly ashy silt loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine, fine, medium, and coarse roots; volcanic ash component; 15 percent pebbles; neutral (pH 6.8); clear smooth boundary. (0 to 3 inches thick)

Bw--3 to 14 inches; light yellowish brown (10YR 6/4) gravelly ashy silt loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine, fine, medium and coarse roots; 5 percent cobbles, 15 percent pebbles; moderately acid (pH 6.0); clear wavy boundary. (7 to 11 inches thick)

2E/Bw--14 to 32 inches; E part (80 percent) is light gray (10YR 7/2) extremely gravelly loamy coarse sand, brown (10YR 5/3) moist, B part (20 percent) is yellowish brown (10YR 5/4) extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; loose, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; 15 percent cobbles, 55 percent pebbles; slightly acid (pH 6.2); gradual wavy boundary. (10 to 40 inches thick)

2C--32 to 60 inches; light gray (10YR 7/2) extremely gravelly loamy coarse sand, brown (10YR 5/3) moist; single grain; loose, nonsticky and nonplastic; few very fine, fine, medium and coarse roots; 20 percent cobbles, 55 percent pebbles; moderately acid (pH 6.0).

TYPE LOCATION: Sanders County, Montana: 1,000 feet south and 1,200 feet east of the northwest corner of section 19, T. 21 N., R. 25 W.

RANGE IN CHARACTERISTICS:

Soil temperature - 44 to 47 degrees F.

Moisture control section - between 12 and 35 inches.

A horizon - Value: 4 or 5 dry
Chroma: 1, 2, or 3
Clay content: 7 to 12 percent
Rock fragments: 5 to 60 percent (0 to 5 percent stones, 0 to 20 percent cobbles, 10 to 30 percent pebbles)
Acid oxalate extractable Al + 1/2 Fe: 1 to 2 percent
Moist bulk density: 1.00 g/cc or less
Reaction: pH 5.6 to 7.3

Bw horizon - Hue: 10YR or 7.5YR
Value: 6 or 7 dry
Chroma: 3 or 4
Texture: ashy loam, ashy silt loam
Clay content: 7 to 12 percent
Rock fragments: 5 to 55 percent (0 to 5 percent stones, 0 to 20 percent cobbles, 5 to 30 percent pebbles)
Acid oxalate extractable Al + 1/2 Fe: 1 to 2 percent
Moist bulk density: 1.00 g/cc or less
Reaction: pH 5.6 to 7.3

2E/Bw horizon - Value: E part: 6 or 7 dry, B part: 5 or 6 dry
Chroma: E part: 2 or 3, B part: 3 or 4
Texture: sandy loam, loamy sand, loamy coarse sand
Clay content: 2 to 10 percent
Rock fragments: 50 to 75 percent (5 to 15 percent cobbles, 45 to 60 percent pebbles)
Reaction: pH 5.6 to 7.3

2C horizon - Chroma: 2 or 3
Texture: loamy sand, loamy coarse sand, sand
Clay content: 0 to 10 percent
Rock fragments: 50 to 85 percent (10 to 25 percent cobbles, 40 to 60 percent pebbles)
Reaction: pH 5.6 to 7.3

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:

Landform - stream terraces, escarpments and alluvial fans.
Elevation - 2,500 to 4,500 feet.
Slope - 0 to 60 percent.
Parent material - volcanic ash over alluvium.
Climate - long, cold winters; moist springs; and warm summers.
Mean annual precipitation - 15 to 30 inches, much of which falls as snow and spring rain.
Mean annual temperature - 42 to 45 degrees F.
Frost-free period - 70 to 105 days.

DRAINAGE AND PERMEABILITY: Excessively drained, rapid permeability.

USE AND VEGETATION: Krause soils are used for timber production, understory grazing, and wildlife habitat. The native vegetation is coniferous forest consisting of Douglas-fir, ponderosa pine, western larch, lodgepole pine and grand fir with an understory of pinegrass, elk sedge, mallow ninebark, and white spirea.

DISTRIBUTION AND EXTENT: Krause soils are of moderate extent in western Montana.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Flathead County, Montana, 1958.

REMARKS: Soil Interpretation Record: MT0652. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the mineral soil surface to 7 inches (A, Bw horizons); ash influenced layers from 1 to 14 inches (A, Bw horizons); a particle-size control section from 10 to 40 inches below the mineral soil surface (Bw, 2E/Bw, 2C horizons). Krause soils have a frigid temperature regime and an ustic moisture regime.

ADDITIONAL DATA: NSSL S91MT-089-001


National Cooperative Soil Survey
U.S.A.