LOCATION POZEGA MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, carbonatic, frigid Aquic Calciustepts
TYPICAL PEDON: Pozega silty clay loam, in rangeland. (Colors are for dry soil unless otherwise noted.)
Az1--0 to 2 inches; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; hard, firm, moderately sticky and moderately plastic; many very fine, fine and medium roots; many fine pores; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 3 inches thick)
Az2--2 to 5 inches; pale brown (10YR 6/3) loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; many very fine, fine and medium roots; many fine pores; violently effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 7 inches thick)
Bk1--5 to 11 inches; light brownish gray (10YR 6/2) very fine sandy loam, brown (10YR 5/3) moist; few fine faint light brown (7.5YR 6/4) redox concentrations; moderate medium subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; common very fine, fine and medium roots; common fine pores; disseminated lime, few fine masses of lime; violently effervescent; slightly alkaline (pH 7.6); clear smooth boundary.
Bk2--11 to 22 inches; light gray (10YR 7/2) very fine sandy loam, light brownish gray (10YR 6/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine, fine and medium roots; common fine pores; 5 percent pebbles; disseminated lime, few fine masses of lime; violently effervescent; slightly alkaline (pH 7.6); clear smooth boundary.
Bk3--22 to 29 inches; light gray (10YR 7/2) silt loam, gray (10YR 6/1) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine, fine and medium roots; common fine pores; 5 percent pebbles; disseminated lime, few fine masses of lime; violently effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (combined thickness of Bk horizons is 17 to 40 inches)
Ckg--29 to 54 inches; white (10YR 8/1) silt loam, light gray (10YR 7/1) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; common fine pores; 10 percent pebbles; disseminated lime, few fine masses of lime; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (20 to 30 inches thick)
2Ck--54 to 60 inches; light gray (10YR 7/2) very gravelly loam, light brownish gray (2.5Y 6/2) moist; few fine distinct dark brown (7.5YR 4/3) redox concentrations; massive; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; 15 percent cobbles and 35 percent pebbles; disseminated lime, few fine masses of lime; violently efervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Deerlodge County, Montana; 200 feet north and 1800 feet west of the SE corner of Sec. 7, T. 5 N., R. 9 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 8 and 24 inches.
Depth to calcic horizon - 3 to 10 inches.
Depth to seasonal high water table - 24 to 42 inches.
Depth to 2C horizon - greater than 40 inches.
Az1 horizon
Hue: 10YR or 2.5Y
Value: 5, 6 or 7 dry; 2, 3 or 4 moist
Chroma: 1 or 2
Clay content: 27 to 40 percent
Rock fragments: 0 to 15 percent pebbles
SAR: 5 to 30
EC: 4 to 25 mmhos/cm
Calcium carbonate equivalent: 5 to 35 percent
Reaction: pH 7.4 to 8.4
Az2 horizon
Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 3 or 4 moist
Chroma: 1, 2 or 3
Texture: silt loam, loam or silty clay loam
Clay content: 18 to 40 percent
Rock fragments: 0 to 15 percent pebbles
SAR: 10 to 20
EC: 4 to 16 mmhos/cm
Calcium carbonate equivalent: 5 to 35 percent
Reaction: pH 7.4 to 8.4
Bk1 horizon
Hue: 10YR or 2.5Y
Value: 6, 7 or 8 dry; 5, 6 or 7 moist
Chroma: 1, 2 or 3
Texture: silty clay loam, clay loam, loam, silt loam or very fine sandy loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 15 percent pebbles
Calcium carbonate equivalent: 10 to 60 percent
Reaction: pH 7.4 to 8.4
Bk2 and Bk3 horizons
Hue: 10YR, 2.5Y or 5Y
Value: 7 or 8 dry; 5 or 6 moist
Chroma: 1 or 2
Texture: loam, very fine sandy loam or silt loam
Clay content: 10 to 18 percent
Rock fragments: 5 to 30 percent--0 to 10 percent cobbles; 5 to 20 percent pebbles
Calcium carbonare equivalent: 40 to 60 percent
Reaction: pH 7.4 to 8.4
Ckg horizon
Hue: 10YR, 2.5Y or 5Y
Value: 7 or 8 dry; 6 or 7 moist
Texture: very fine sandy loam, loam or silt loam
Clay content: 10 to 25 percent
Rock fragments: 10 to 35 percent--0 to 10 percent cobbles; 10 to 25 percent pebbles
Calcium carbonate equivalent: 40 to 60
Reaction: pH 7.4 to 8.4
2Ck horizon
Hue: 10YR, 2.5Y or 5Y
Value: 6, 7 or 8 dry; 5 or 6 moist
Chroma: 1 or 2
Texture: loamy sand, sand, sandy loam or loam
Clay content: 5 to 15 percent
Rock fragments: 35 to 70 percent--10 to 30 percent cobbles; 25 to 40 percent pebbles
Calcium carbonate equivalent: 10 to 30 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - low stream terraces and glacial outwash plains
Elevation - 4600 to 5000 feet.
Slope - 0 to 4 percent
Parent material - calcareous alluvium
Climate - long, cold winters; moist springs; warm dry summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 39 to 45 degrees.
Frost free season - 90 to 105 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow permeability.
USE AND VEGETATION: Pozega soils are used mainly for pasture, rangeland grazing and as wildlife habitat. The potential native vegetation is mainly basin wildrye, alkali cordgrass and alkali sacaton, with small amounts of Nevada bluegrass, aster and greasewood.
DISTRIBUTION AND EXTENT: Pozega soils are of small extent in Western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Deerlodge County, Montana, 2001.
REMARKS: Soil interpretation record: MT1431. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 5 inches (Az1, and Az2 horizons); a calcic horizon from 22 to 54 inches (Bk1, Bk2, Bk3 and Ckg horizons); a lithological discontinuity at 54 inches (2C horizon); a particle size control section from 10 to 40 inches (Bk1, Bk2, Bk3 and Ckg horizons). Pozega soils have a frigid soil temperature regime and an ustic moisture regime bordering on aridic.