Soil Survey of Sweet Grass County Area, Montana - Soil Data Mart

Sweet Grass County Area, Montana—Part I 81
sec. 29, T. 3 N., R. 15 E.; USGS Otter Creek School
topographic quadrangle (lat. 45 o 58'38" N.; long.
109 o 52'57" W.)
Ap—0 to 5 inches; grayish brown (10YR 5/2) loam,
very dark grayish brown (10YR 3/2) moist;
moderate medium platy structure parting to
moderate fine granular; soft, very friable, slightly
sticky, slightly plastic; common very fine roots;
common very fine pores; slightly effervescent;
slightly alkaline (pH 7.6); abrupt smooth
boundary.
C1—5 to 12 inches; light brownish gray (2.5Y 6/2)
stratified loam, dark grayish brown (2.5Y 4/2)
moist; moderate medium angular blocky
structure; moderately hard, firm, slightly sticky,
slightly plastic; common very fine roots; common
very fine pores; strongly effervescent; moderately
alkaline (pH 8.4); abrupt wavy boundary.
C2—12 to 22 inches; light brownish gray (2.5Y 6/2)
stratified loam, dark grayish brown (2.5Y 4/2)
moist; moderate fine subangular blocky structure;
moderately hard, friable, slightly sticky, slightly
plastic; common very fine roots; common very
fine pores; strongly effervescent; slightly alkaline
(pH 7.8); abrupt smooth boundary.
C3—22 to 34 inches; light brownish gray (2.5Y 6/2)
stratified very fine sandy loam and loam, grayish
brown (2.5Y 5/2) moist; massive; slightly hard,
friable, slightly sticky, slightly plastic; common
very fine roots; many very fine pores; strongly
effervescent; moderately alkaline (pH 8.2); abrupt
smooth boundary.
C4—34 to 60 inches; grayish brown (2.5Y 5/2)
stratified loam and very fine sandy loam, dark
grayish brown (2.5Y 4/2) moist; massive; slightly
hard, very friable, slightly sticky, slightly plastic;
few very fine and fine roots; few very fine and fine
pores; strongly effervescent; moderately alkaline
(pH 8.2).
Range in Characteristics
Soil temperature: 42 to 47 degrees F
Moisture control section: Between 4 and 12 inches
Thickness of the mollic epipedon: 5 to 15 inches
Notes: The C horizons are stratified with finer and
coarser materials.
A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture (less than 2 mm): Loam
Clay content: 18 to 27 percent
Content of rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 1 to 5 percent
Reaction: pH 6.6 to 8.4
C horizons
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 7 dry; 3 to 6 moist
Chroma: 2 to 4
Texture (less than 2 mm): Stratified loam, fine
sandy loam, silt loam, silty clay loam, sandy
loam, or very fine sandy loam
Clay content: 18 to 35 percent
Content of rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 5 to 10 percent
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 7.4 to 9.0
Kremlin Series
Depth class: Very deep (greater than 60 inches)
Drainage class: Well drained
Permeability: Moderate (0.6 to 2.0 inches/hour)
Landform: Fan, stream terrace, terrace, swale on fan,
and swale on plain
Parent material: Loamy alluvium
Slope range: 0 to 15 percent
Elevation range: 3,750 to 5,200 feet
Mean annual precipitation: 10 to 14 inches
Mean annual air temperature: 43 to 46 degrees F
Frost-free period: 95 to 125 days
Taxonomic Class: Fine-loamy, mixed, superactive,
frigid Aridic Haplustolls
Typical Pedon
Kremlin loam, 1,000 feet south and 1,700 feet east
of the northwest corner of sec. 23, T. 30 N., R. 10 E.;
Hill County, Montana.
Ap—0 to 6 inches; grayish brown (10YR 5/2) loam,
very dark grayish brown (10YR 3/2) moist;
moderate fine granular structure; soft, very
friable, moderately sticky, moderately plastic;
many very fine and fine roots; neutral (pH 6.8);
abrupt smooth boundary.
A2—6 to 11 inches; dark grayish brown (2.5Y 4/2)
loam, very dark grayish brown (2.5Y 3/2) moist;
moderate medium prismatic structure parting to
moderate fine and medium subangular blocky;
slightly hard, very friable, moderately sticky,
moderately plastic; many very fine roots; many
very fine pores; neutral (pH 6.8); clear smooth
boundary.