LOCATION MODESTY MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aquic Haplustolls
TYPICAL PEDON: Modesty silty clay loam, in cropland (colors are for dry soil unless otherwise noted).
Oe--0 to 1 inch; partially decomposed organic matter. (0 to 1 inch thick)
A--1 to 9 inches; dark gray (10YR 4/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate fine granular structure; very hard, firm, nonsticky and moderately plastic; many fine and very fine roots; common fine and very fine irregular pores; neutral (pH 6.6); clear smooth boundary. (6 to 9 inches thick)
Bw1--9 to 16 inches; gray (10YR 5/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate very fine subangular blocky structure; very hard, firm, nonsticky and moderately plastic; many fine and very fine roots; common fine and very fine irregular pores; neutral (pH 6.6); clear smooth boundary. (4 to 10 inches thick)
Bw2--16 to 32 inches; gray (10YR 6/1) silty clay loam, very dark gray (10YR 3/1) moist; moderate fine and medium subangular blocky structure; very hard, firm, nonsticky and moderately plastic; common fine and very fine roots; common fine and very fine irregular pores; neutral (pH 6.6); clear smooth boundary. (10 to 20 inches thick)
Bw3--32 to 39 inches; light gray (10YR 7/2) loam, dark grayish brown (10YR 4/2) moist; few faint strong brown (7.5YR 5/6) redox concentrations; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common fine and very fine irregular pores; slightly alkaline (pH 7.4); clear smooth boundary. (17 to 30 inches thick)
2C--39 to 60 inches; light gray (10YR 7/2) very gravelly loam, grayish brown (10YR 5/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common fine and very fine irregular pores; 10 percent cobbles, 25 percent pebbles; slightly alkaline (pH 7.6).
TYPE LOCATION: Granite County, Montana; 2,550 feet west and 1,300 feet south of the NE corner of sec. 19, T. 10 N., R. 12 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 46 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to 2C horizon - 37 to 60 inches.
Depth to seasonal high water table - 24 to 42 inches.
A horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 0, 1, or 2
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles
Reaction: pH 6.6 to 7.3
Bw1 horizon - Hue: 10YR or 7.5YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 1 or 2
Texture: silty clay loam, silt loam, or loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles
Reaction: pH 6.6 to 7.3
Bw2 horizon - Hue: 10YR or 7.5YR
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1, 2, 3, 4, or 5 moist
Texture: loam, clay loam, silt loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Calcium carbonate equivalent: 0 to 10 percent
Reaction: pH 6.6 to 7.8
Bw3 horizon - Hue: 10YR or 7.5YR
Value: 5, 6, or 7 dry; 3 or 4 moist
Chroma: 1, 2, 3, 4, or 5 moist
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Reaction: pH 6.6 to 7.8
2C horizon - Hue: 10YR or 7.5YR
Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2, 3, 4, or 5 moist
Texture: loam or sandy loam
Clay content: 18 to 27 percent
Rock fragments: 15 to 45 percent--5 to 15 percent cobbles, 10 to 30 percent pebbles
Reaction: pH 6.6 to 7.8
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans; stream terraces; glacial outwash plains.
Elevation - 3,600 to 4,600 feet.
Slope - 0 to 4 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 19 inches.
Mean annual air temperature - 41 to 45 degrees F.
Frost-free period - 70 to 105 days.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow permeability above the discontinuity and moderately rapid permeability in the discontinuity.
USE AND VEGETATION: These soils are used mainly for irrigated cropland, hay and pasture. The native vegetation is mainly tall reedgrass, tufted hairgrass, prairie cordgrass, basin wildrye, and Nebraska sedge.
DISTRIBUTION AND EXTENT: The Modesty series is of small extent in the mountain valleys of southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Granite County, Montana, 1997.
REMARKS: Soil interpretations record: MT1289. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 1 to 16 inches (A, Bw horizons); a cambic horizon from 16 to 39 inches (Bw2, Bw3 horizons); a lithologic discontinuity at 39 inches (2C horizon); a particle-size control section from 11 to 41 inches (Bw1, Bw2, Bw3, 2C horizons). Modesty soils have a frigid soil temperature regime and an ustic moisture regime that borders on aquic.