LOCATION DELETTE MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Hapludolls
TYPICAL PEDON: Delette loam, in forestland (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; forest litter of leaves, twigs, and partly decomposed organic matter.
A1--1 to 6 inches; very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; moderate fine and medium granular structure; slightly hard, very friable, slightly sticky, slightly plastic; common coarse and many very fine, fine, and medium roots; many very fine pores; trace angular gravel; many worm casts; moderately acid (pH 5.8); clear wavy boundary. (2 to 15 inches thick)
A2--6 to 17 inches; brown (7.5YR 4/2) loam, dark brown (7.5YR 3/2) moist; weak fine and medium subangular blocky structure parting to weak very fine granular; hard, very friable, slightly sticky, slightly plastic; common medium and coarse and many very fine and fine roots; many very fine and fine pores; trace angular gravel; moderately acid (pH 5.8); diffuse wavy boundary. (5 to 12 inches thick)
A3--17 to 51 inches; brown (7.5YR 5/2) loam, dark brown (7.5YR 3/2) moist; weak fine and medium subangular blocky structure parting to weak very fine granular; hard, friable, slightly sticky, slightly plastic; common medium and coarse and many very fine and fine roots; many very fine and fine pores; trace angular gravel; streaks and patches of pinkish gray (7.5YR 6/2) silt and fine sand; few faint brown (10YR 5/3) redox concentrations; moderately acid (pH 5.8); clear wavy boundary. (10 to 35 inches thick)
A&B--51 to 60 inches; 60 percent pinkish gray (7.5YR 6/2) loam A part and about 40 percent B material in pockets and thin bands of brown (7.5YR 5/2) clay loam, brown (7.5YR 4/2) moist; weak fine or medium subangular blocky structure; very hard, firm, moderately sticky, moderately plastic; faint clay films in some pores; common very fine and fine roots; many very fine and fine pores; trace angular gravel; common faint gray (N 6/0) redox depletions; strongly acid (pH 5.4).
TYPE LOCATION: Fergus County, Montana: 220 meters west and 740 meters north of the southeast corner of sec. 28, T. 14 N., R. 18 E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 42 to 45 degrees F
Thickness of the mollic epipedon: 17 to 50 inches
Organic carbon: 0.3 percent or more to a depth of 125 cm or more (estimate)
Depth to seasonal high water table: 36 to 60 inches
A1 and A2 horizons
Hue: 7.5YR or 10YR
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 1 or 2
Texture: loam
Clay content: 18 to 25 percent
Content of rock fragments: 0 to 15 percent--0 to trace angular cobbles; 0 to 15 percent angular gravel
Reaction: pH 5.6 to 7.3
A3 horizon
Hue: 7.5YR or 10YR
Value: 5 dry; 3 moist
Chroma: 2
Texture: loam
Clay content: 18 to 27 percent
Content of rock fragments: 0 to 15 percent--0 to trace angular cobbles; 0 to 15 percent angular gravel
Reaction: pH 5.1 to 6.5
A&B horizon
Hue: 7.5YR or 10YR
Value: 4 to 6 dry; 4 moist
Chroma: 2
Texture: loam or clay loam
Clay content: 18 to 35 percent
Content of rock fragments: 0 to 15 percent--0 to trace angular cobbles; 0 to 15 percent angular gravel
Reaction: pH 5.1 to 7.3
COMPETING SERIES:
Darnen (MN+ND SD) has free carbonates at a depth of 20 to 60 inches.
Everts (MN) has coarse-textured material at a depth of 40 to 55 inches.
Frolic (NM+UT WY) has a solum 20 to 50 inches thick.
La Prairie (ND+MN SD) has free carbonates below a depth of 0 to 40 inches.
Southhaven (MN) does not have an A&B horizon; is well drained.
GEOGRAPHIC SETTING:
Landform: Fans and footslopes
Elevation: 4,600 to 5,510 feet
Slope: 0 to 25 percent
Parent material: Alluvium and colluvium from mixed rock sources
Climate: Cool with moist springs and summers
Mean annual precipitation: 19 to 30 inches
Mean annual air temperature: 40 to 43 degrees F
Frost-free period: 80 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Adel (MT+CO ID NM UT WY) is well drained; has a cryic temperature regime.
Castner (MT+CO UT WY) is shallow over bedrock.
Cheadle (MT+CO UT WY) is shallow over bedrock.
Hibar (MT) is moderately deep to bedrock.
Teton (MT+UT) is moderately deep to bedrock.
Tomty (MT) has a fine control section; is somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium or rapid runoff; moderate permeability to about 127 cm and slow below that depth
USE AND VEGETATION: Delette soils are used mainly for woodland and rangeland. To a lesser degree, they are used for hayland. The potential native vegetation is mainly an overstory of quaking aspen and an understory of black hawthorn, common snowberry, Kentucky bluegrass, blue wildrye, timothy, white spiraea, northern bedstraw, western meadowrue, and common houndstongue.
DISTRIBUTION AND EXTENT: Delette soils are of limited extent in central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fergus County, Montana, 1979
REMARKS:
Diagnostic horizons and features recognized in this pedon:
- a mollic epipedon from 1 to 51 inches (A horizons)
- a cambic horizon from 51 to 60 inches (A&B horizon)
Delette soils have a frigid temperature regime and a udic moisture regime.