LOCATION TURRAH MT
Established Series
Rev. BDD-JAL-EMM
09/2014
TURRAH SERIES
The Turrah series consists of very deep, poorly drained soils that formed in alluvium. These soils are on stream terraces and flood plains. Slopes are 0 to 4 percent. Mean annual precipitation is about 16 inches, and mean annual temperature is about 43 degrees F.
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Cumulic Endoaquolls
TYPICAL PEDON: Turrah silty clay loam, in hayland (colors are for moist soil unless otherwise noted).
A1--0 to 4 inches; black (10YR 2/1) silty clay loam, black (10YR 2/1) dry; moderate fine and medium subangular structure; very hard, firm, moderately sticky and moderately plastic; many very fine roots; many very fine pores; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 8 inches thick)
A2--4 to 12 inches; black (10YR 2/1) clay, black (10YR 2/1) dry; moderate fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; many very fine roots; many very fine pores; common fine distinct brownish yellow (10YR 6/6) dry redox concentrations; neutral (pH 7.0); clear smooth boundary. (4 to 10 inches thick)
Bg1--12 to 22 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine roots; many very fine pores; common black (10YR 2/1) organic stains; common medium distinct brownish yellow (10YR 6/6) dry redox concentrations; neutral (pH 7.0); clear smooth boundary.
Bg2--22 to 38 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; strong medium subangular blocky structure; very hard, firm, moderately sticky and very plastic; common very fine and fine roots; common very fine pores; many fine and medium prominent brownish yellow (10YR 6/6) dry and dark yellowish brown (10YR 4/4) dry redox concentrations; slightly alkaline (pH 7.5); abrupt smooth boundary. (Combined thickness of the Bg horizon is 14 to 34 inches.)
2Cg--38 to 60 inches; gray (5Y 5/1) very gravelly sandy clay loam, grayish brown (2.5Y 5/2) dry; massive; very hard, friable, moderately sticky and moderately plastic; 60 percent gravel; common fine distinct brownish yellow (10YR 6/6) dry and dark yellowish brown (10YR 4/4) dry redox concentrations; slightly alkaline (pH 7.5).
TYPE LOCATION: Missoula County, Montana; 1,300 feet east and 700 feet north of the SW corner of sec. 21, T. 13 N., R. 15 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 24 to 48 inches.
Depth to water table - 12 to 24 inches.
A thin, less than 3 inch organic layer is allowed.
A1 horizon
Hue: 10YR, 2.5Y, or 5Y
Value: 2, 3, or 4 dry; 2, 2.5, or 3 moist
Chroma: 1 or 2, dry or moist
Texture: clay loam, silty clay loam
Clay content: 27 to 40 percent
Reaction: pH 5.6 to 7.3
A2 horizon
Hue: 10YR, 2.5Y, or 5Y
Value: 2, 3, or 4 dry; 2, 2.5, or 3 moist
Chroma: 1 or 2, dry or moist
Redox concentrations: 10YR 4/3, 10YR 4/4, 10YR 4/6, 10YR 5/6, 10YR 6/4, 10YR 6/6
Texture: clay, silty clay loam, or silty clay
Clay content: 35 to 60 percent
Reaction: pH 5.6 to 7.3
Bg horizons
Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, or 6 dry; 2, 2.5, 3, 4, or 5 moist
Chroma: 0, 1, 2, or 3 dry or moist
Redox concentrations: 10YR 4/4, 10YR 4/6, 10YR 5/6, 10YR 6/4, 10YR 6/6, or 7.5YR 5/6
Texture: clay, silty clay, silty clay loam, or clay loam
Clay content: 35 to 60 percent
Reaction: pH 6.6 to 7.8
2Cg horizon
Hue: 2.5Y or 5Y
Value: 4, 5, or 6 dry; 4 or 5 moist
Chroma: 1 or 2, dry or moist
Redox concentrations: 10YR 6/6, 10YR 4/6, or 10YR 4/4
Texture: sandy clay loam, sandy loam, or clay loam
Clay content: 20 to 40 percent
Rock fragments: 35 to 85 percent--0 to 35 percent cobbles, 20 to 60 percent gravel
Reaction: pH 6.6 to 7.8
COMPETING SERIES:
Furia (CO) - Do not have a lithologic discontinuity
GEOGRAPHIC SETTING:
Landform - stream terraces and flood plains.
Elevation - 3,500 to 6,000 feet.
Slope - 0 to 4 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 22 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 70 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Poorly drained; slow permeability.
USE AND VEGETATION: Turrah soils are used as pastureland and hayland.
DISTRIBUTION AND EXTENT: Turrah soils are inextensive in western Montana. MLRAs 43B or 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County, Montana, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - the zone from the soil surface to 38 inches (A1, A2, Bg1, Bg2 horizons)
Gleyed horizons - the zone from 12 to 60 inches (Bg1, Bg2, 2Cg horizons)
Particle-size control section - the zone from 10 to 40 inches (A2, Bg1, Bg2, 2Cg horizons).
Turrah soils have a frigid temperature regime and an aquic moisture regime.
Soil interpretation record: MT0625, MT8102, MT8144.
National Cooperative Soil Survey
U.S.A.