LOCATION RADERSBURG MT+CO
Established Series
Rev. JAO-JCK
04/2021
RADERSBURG SERIES
The Radersburg series consists of very deep, well drained soils formed in alluvium or colluvium. These soils are on alluvial fans, stream terraces, fan remnants, and escarpments. Slopes are 0 to 60 percent. Mean annual precipitation is about 330 mm, and mean annual temperature is about 5.5 degrees C.
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Radersburg very cobbly loam, rangeland (colors are for dry soil unless otherwise noted).
A--0 to 10 cm; grayish brown (10YR 5/2) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate fine platy structure parting to moderate very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many fine and very fine roots and pores; 55 percent gravel and cobbles; slightly alkaline (pH 7.8); abrupt smooth boundary. (8 to 13 cm thick)
Bt--10 to 38 cm; brown (10YR 5/3) very cobbly clay, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to strong fine angular blocky; hard, firm, sticky and plastic; many fine and very fine roots and pores; common distinct clay films on all faces of peds; 40 percent gravel and cobbles; slightly alkaline (pH 7.8); clear smooth boundary. (18 to 38 cm thick)
Bk--38 to 76 cm; light gray (10YR 7/2) very cobbly silt loam, grayish brown (2.5Y 5/2) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common distinct calcium carbonate coats on bottom surfaces of rock fragments; 45 percent gravel and cobbles; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (25 to 51 cm thick)
C--76 to 152 cm; light yellowish brown (2.5Y 6/4) cobbly loam, olive brown (2.5Y 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; 55 percent gravel and cobbles; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Broadwater County, Montana; 91 meters west of the center of sec. 28, T. 8 N., R 1 E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 4.4 to 8.0 degrees C
Mollic epipedon thickness - 18 to 38 cm
A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: loam or clay loam
Clay content: 10 to 35 percent
Rock fragments: 0 to 60 percent--0 to 25 percent gravel; 0 to 30 percent cobbles; 0 to 10 percent stones
Reaction: pH 6.6 to 7.8
Bt horizon
Hue: 10YR or 2.5Y
Value: 4 or 5 dry; 3 moist
Chroma: 2 or 3
Texture: clay or clay loam
Clay content: 35 to 55 percent
Rock fragments: 35 to 65 percent--15 to 55 percent gravel; 10 to 50 percent cobbles; 0 to 20 percent stones
Reaction: pH 7.4 to 8.0
Bk horizon
Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: silt loam or clay loam
Clay content: 25 to 40 percent
Rock fragments: 25 to 65 percent--15 to 55 percent gravel; 10 to 50 percent cobbles; 0 to 10 percent stones
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
C horizon
Hue: 10YR or 2.5Y
Value: 5, 6, 7, or 8 dry; 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 25 to 65 percent--15 to 55 percent gravel; 10 to 50 percent cobbles; 0 to 10 percent stones
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans, stream terraces, fan remnants, and escarpments
Elevation - 1,158 to 1,585 meters
Slope - 0 to 60 percent
Parent material - alluvium and colluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 254 mm to 406 mm
Mean annual temperature - 3.3 to 7.2 degrees C
Frost-free period - 70 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability in the Bt horizon and moderate permeability below.
USE AND VEGETATION: Radersburg soils are used as rangeland. Potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, green needlegrass, needleandthread, blue grama, sageworts, and cacti.
DISTRIBUTION AND EXTENT: Radersburg soils are of moderate extent in Montana and Colorado. MLRAs - 34B, 44B, 46, 48A, 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Broadwater County area, Montana, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 38 cm (A and Bt horizons)
Argillic horizon - from 10 to 38 cm (Bt horizon)
Secondary calcium carbonate accumulation - from 38 to 76 cm (Bk horizon)
Particle-size control section - from 10 to 38 cm (Bt horizon)
Radersburg soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
ADDITIONAL DATA: Soil Interpretations Records - MT0207, MT1025, and MT0789.
National Cooperative Soil Survey
U.S.A.