LOCATION DAVIDELL MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Haplargidic Natrustalfs
TYPICAL PEDON: Davidell silty clay loam, grassland (colors are for dry soil unless otherwise noted).
E1--0 to 2 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; moderate thin platy structure; soft, friable, nonsticky and nonplastic; many very fine roots; many fine irregular pores; slightly alkaline (pH 7.6); abrupt smooth boundary.
E2--2 to 4 inches; light brownish gray (2.5Y 6/2) loam, dark grayish brown (2.5Y 4/2) moist; weak medium angular blocky structure parting to weak medium platy; slightly hard, friable, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; slightly alkaline (pH 7.6); clear smooth boundary. (Combined E horizons is 3 to 7 inches thick)
Bt--4 to 9 inches; grayish brown (2.5Y 5/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to strong fine angular blocky; hard, firm, sticky and plastic; many very fine roots; few very fine tubular pores; many faint clay films on faces of peds and in pores; slightly alkaline (pH 7.6); abrupt smooth boundary. (4 to 6 inches thick)
Bk1--9 to 25 inches; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; weak medium angular blocky structure; hard, firm, sticky and plastic; common very fine roots; few very fine tubular pores; few fine masses of lime; disseminated lime; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
Bk2--25 to 38 inches; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, friable, slightly sticky and plastic; few very fine roots; few very fine tubular pores; few fine masses of lime; disseminated lime; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (Combined thickness of Bk horizons is 19 to 55 inches).
Byz--38 to 60 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; few fine masses of gypsum and other salts; strongly effervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Rosebud County, Montana; 2,000 feet west and 1,500 feet south of the NE corner of sec. 19, T. 9 N., R. 40 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches, dry 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 or higher.
Depth to Bk horizon - 6 to 14 inches.
E horizons - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: loam, silt loam, clay loam or silty clay loam
Clay content: 15 to 33 percent
Reaction: pH 6.6 to 7.8
Bt horizon - Hue: 2.5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam or silty clay loam
Clay content: 27 to 35 percent
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 7.4 to 8.4
Bk horizons - Hue: 2.5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam or silty clay loam
Clay content: 27 to 32 percent
Calcium carbonate equivalent: 5 to 15 percent
Electrical conductivity: 4 to 8 mmhos/cm
Sodium absorption ratio: 8 to 15
Reaction: pH 7.9 to 9.0
Byz horizon - Hue: 2.5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: loam, silt loam, clay loam, or silty clay loam
Clay content: 24 to 30 percent
EC: 8 to 16 mmhos/cm
SAR: 15 to 30
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Debs (MN) - does not have a horizon of gypsum or other salt accumulations; is dry in all parts of the moisture control section less than 90 cumulative days per year.
Ivanell (MT) - has paralithic contact at 20 to 40 inches.
Vanstel (MT) - has SAR of less than 8 throughout; does not have horizon of gypsum or other salt accumulation.
Virkula (SD) - does not have a horizon of secondary calcium carbonate accumulation; is medium or slightly acid in the argillic horizon.
Winteridge (UT) - does not have an albic horizon; has hues redder than 10YR in the surface and in the argillic horizons.
GEOGRAPHIC SETTING:
Landform - stream terraces; alluvial fans; sedimentary plains.
Elevation - 2,200 to 3,000 feet.
Slope- 0 to 8 percent.
Parent material - alluvium or colluvium.
Climate - long cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual temperature - 39 to 45 degrees.
Frost free period - 100 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Davidell soils are used mainly for rangeland. Potential native vegetation is mainly western wheatgrass, green needlegrass, needleandthread, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Davidell soils are of small extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Rosebud County, Montana, 1985. Origin of name is an abandoned post office in Rosebud County.
REMARKS: Soil interpretations record: MT0350. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 4 inches which is also an albic horizon (E1, E2 horizons); an argillic horizon from 4 to 9 inches (Bt horizon); a horizon of secondary calcium carbonate accumulation from 9 to 38 inches (Bk1, Bk2 horizons); a horizon of gypsum and other salt accumulation (Byz horizon). A particle-size control section from 4 to 40 inches (Bt, BK1, Bk2, Byz horizon). The Davidell soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.