LOCATION TRUSCREEK MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Calcic Haploxerolls
TYPICAL PEDON: Truscreek silt loam, in cropland (colors are for dry soil unless otherwise noted).
Ap1--0 to 9 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; common fine and very fine tubular pores; neutral (pH 6.6); abrupt smooth boundary. (8 to 10 inches thick)
Ap2--9 to 12 inches; pale brown (10YR 6/3) silt loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine roots; common fine pores; neutral (pH 6.8); clear smooth boundary. (0 to 4 inches thick)
Bw--12 to 25 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; few very fine and fine pores; slightly alkaline (pH 7.6); clear wavy boundary. (10 to 16 inches thick)
Bk--25 to 32 inches; very pale brown (10YR 8/2) silt loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; few very fine and fine pores; common fine threads of lime; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (6 to 10 inches thick)
C1--32 to 42 inches; very pale brown (10YR 8/2) silt loam, pale brown (10YR 6/3) moist; massive; fine stratification; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few very fine pores; disseminated lime; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (8 to 12 inches thick)
C2--42 to 60 inches; very pale brown (10YR 8/2) silt loam, pale brown (10YR 6/3) moist; massive; fine stratification; few 1/4- to 1/2-inch thick varves; slightly hard, friable, slightly sticky and slightly plastic; disseminated lime; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Lake County, Montana; 2,400 feet west and 1,350 feet south of the NE corner of sec. 32, T. 22 N., R. 20 N.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 8 to 14 inches.
Control section - 18 to 27 percent clay.
Depth to Bk horizon - 19 to 30 inches.
Ap1 horizon - Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Reaction: pH 6.1 to 7.3
Ap2 horizon - Value: 5 or 6 dry, 3 or 4 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Reaction: pH 6.6 to 7.3
Bw horizon - Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4
Clay content: 18 to 27 percent
Reaction: pH 7.4 to 7.8
Few durinodes in some pedons.
Bk horizon - Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2 or 3
Clay content: 18 to 27 percent
Calcium carbonate equivalent: 15 to 20 percent
Reaction: pH 7.9 to 8.4
Few durinodes in some pedons.
C horizon - Value: 7 or 8 dry, 5 or 6 moist
Chroma: 2 or 3
Clay content: 12 to 27 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES: This is the Huffman (ID) series. The Huffman soils formed mainly in loess material and do not have the stratification characteristic of soils formed in glaciofluvial or glaciolacustrine deposits, also they have lime as shallow as 10 inches.
GEOGRAPHIC SETTING: The Truscreek soils are on dissected alluvial fans and stream terraces. Elevations are 2,800 to 3,300. Slopes are 0 to 8 percent. These soils formed in glaciofluvial or glaciolacustrine deposits. The climate is characterized by long, cold winters; moist springs; and warm, dry summers. Mean annual precipitation is 15 to 19 inches and is mainly rain in early spring and late fall. Mean annual temperature is 42 to 45 degrees F. The frost-free period is 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Polson series. Polson soils have a natric horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Truscreek soils are used for irrigated and dryland crops and as pastureland.
DISTRIBUTION AND EXTENT: Truscreek soils are of small extent in valleys of western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1983.
REMARKS: Soil interpretation records: MT1001. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 9 inches (Ap1 horizon); a cambic horizon from 9 to 25 inches (Ap2, Bw horizons); a calcic horizon from 25 to 32 inches (Bk horizon); a particle-size control section from 10 to 40 inches (Ap2, Bw, Bk, C1 horizons). Truscreek soils have a frigid temperature regime and a xeric moisture regime.