LOCATION BIRNEY MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Haplustepts
TYPICAL PEDON: Birney channery loam, grassland. (Colors are for dry soil unless otherwise noted)
A--0 to 5 inches; reddish brown (5YR 5/4) channery loam, reddish brown (5YR 4/4) moist; weak thick platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; 15 percent hard shale and sandstone channers; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 8 inches thick)
Bw--5 to 11 inches; reddish brown (5YR 5/3) channery loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure parting to weak fine crumbs; soft, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; 20 percent hard shale and sandstone fragments; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 10 inches thick)
Bk1--11 to 29 inches; light reddish brown (5YR 6/4) extremely channery sandy loam, reddish brown (5YR 5/4) moist; weak fine granular structure; hard, very friable, slightly sticky and nonplastic; common very fine and fine roots matted around coarse fragments; common to many distinct lime casts on underside of rock fragments; 65 percent hard shale and sandstone fragments; violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (10 to 30 inches thick)
Bk2--29 to 60 inches; reddish yellow (5YR 6/6) extremely channery sandy loam, red (2.5YR 4/6) moist; massive; soft, very friable, slightly sticky and nonplastic; few fine roots; common to many distinct lime casts on undersides of coarse fragments; 65 percent hard shale and sandstone fragments; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Rosebud County, Montana; 2,250 feet east and 550 feet north of the SW corner of sec. 14, T. 3 S, R. 44 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 8 and 24 inches, dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to Bk horizon - 10 to 15 inches.
A C horizon is allowed.
A horizon - Hue: 5YR, 7.5YR, 10YR
Value: 4, 5, or 6 dry; 3 or 4 moist
Chroma: 2, 3, or 4
Texture: loam or sandy loam
Clay content: 10 to 25 percent
Rock fragments: 0 to 35 percent channers
Effervescence: slight to strong
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.4 to 8.4
Bw horizon - Hue: 5YR, 7.5YR, 10YR
Value: 4, 5, or 6 dry; 4 or 5 moist
Chroma: 2, 3, 4, or 6
Texture: loam or sandy loam
Clay content: 10 to 25 percent
Rock fragments: 0 to 35 percent channers or pebbles
Effervescence: slight to strong
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.4 to 8.4
Bk horizons - Hue: 5YR, 7.5YR, 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, 4, or 6
Texture: loam, sandy loam, or fine sandy loam
Clay content: 10 to 25 percent
Rock fragments: 35 to 80 percent--0 to 20 percent flagstones, 35 to 60 percent channers or pebbles
Effervescence: strong or violent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - sedimentary plains; hills; escarpments; alluvial fans and stream terraces.
Elevation - 1,900 to 5,200 feet.
Slope- 0 to 70 percent.
Parent material - alluvium or colluvium derived from semiconsolidated interbedded sandstone and shale.
Climate - long cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 15 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 95 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Birney soils are used mainly for rangeland; a few areas are used for woodland. Potential vegetation is mainly bluebunch wheatgrass, western wheatgrass, needleandthread, little bluestem, sideoats grama, blue grama, some forbs, and shrubs. Some areas have a thin stand of ponderosa pine and juniper.
DISTRIBUTION AND EXTENT: Birney soils are of moderate extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Stillwater County, Montana, 1975.
REMARKS: Soil interpretations records: MT0166, MT1055.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the soil surface to a depth of 7 inches (after mixing) (A and Bw horizons); cambic horizon - the zone from 5 to 11 inches (Bw horizons); accumulations of secondary calcium carbonates - the zone from 11 to 60 inches (Bk1 and Bk2 horizons); particle-size control section - the zone from 10 to 40 inches (Bw, Bk1 and Bk2 horizons). The Birney soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.