LOCATION LOTHAIR MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, calcareous, frigid Aridic Ustorthents
TYPICAL PEDON: Lothair silty clay loam, rangeland (colors are for dry soil unless otherwise noted).
A--0 to 3 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (3 to 6 inches thick)
Cy1--3 to 14 inches; light brownish gray (2.5Y 6/2) silty clay, grayish brown (2.5Y 5/2) moist; common distinct reddish brown (5YR 5/4) and yellowish brown (10YR 5/6) relict mottles; moderate very fine blocky structure; very hard, friable, moderately sticky and very plastic; many thin stratifications of silty clay loam; common fine roots and pores; few fine pebbles; many fine filaments and masses of gypsum; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (9 to 13 inches thick)
Cy2--14 to 60 inches; light brownish gray (2.5Y 6/2) light silty clay, dark grayish brown (2.5Y 4/2) moist; common distinct reddish brown (5YR 5/4) and yellowish brown (10YR 5/6) relict mottles; moderate fine blocky structure; extremely hard, firm, moderately sticky and very plastic; many thin stratifications of silty clay loam and silt loam; few fine roots and pores; few fine pebbles; common filaments and masses and few large crystals of gypsum; slightly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Cascade County, Montana; 400 feet east and 1,200 feet north of the SW corner of sec. 12, T. 22 N., R. 5 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 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 higher than 41 degrees F.
A horizon - Hue: 5Y, 2.5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: silty clay loam or silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 5 percent pebbles
Reaction: pH 7.4 to 8.4
Cy horizons - Hue: 5Y, 2.5Y or 10YR
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: stratified silty clay or silty clay loam
Clay content: 35 to 45 percent
Rock fragments: 0 to 5 percent pebbles
Calcium Carbonate Equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - alluvial fans and stream terraces
Elevation - 3,000 to 4,500 feet
Slope - 0 to 70 percent
Parent material - alluvium and lacustrine deposits
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 10 to 14 inches
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 105 to 135 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brocko, Lambeth, and Sunburst soils. Brocko soils have coarse-silty control sections and calcic horizons. Lambeth soils have fine-silty control sections. Sunburst soils have glacial till substratum and smectitic mineralogy.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Lothair soils are used mainly for rangeland; some areas are in irrigated crops. Potential native vegetation is mainly western wheatgrass, bluebunch wheatgrass, green needlegrass, blue grama, and forbs.
DISTRIBUTION AND EXTENT: Lothair soils are moderately extensive in eastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Broadwater County Area, Montana, 1971.
REMARKS: Soil Interpretations Record: MT0113. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 7 inches mixed (A and Cy1 horizons); an accumulation of gypsum from 3 to 60 inches (Cy1 and Cy2 horizons); a particle-size control section from 10 to 40 inches (Cy1 and Cy2 horizons). Lothair soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
Classification changed from Ustic Torriorthents to Aridic Ustorthents in 1994.