LOCATION HARLEM MT+CO SD WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Ustic Torrifluvents
TYPICAL PEDON: Harlem silty clay loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 8 inches; grayish brown (2.5Y 5/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium and fine granular structure; very hard, firm, sticky and plastic; many fine and few medium roots; slightly effervescent; mildly alkaline (pH 7.6); abrupt smooth boundary. (4 to 10 inches thick)
C1--8 to 24 inches; grayish brown (2.5Y 5/2) heavy silty clay loam consisting of thin strata of silt loam and silty clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and fine subangular blocky structure; very hard, firm, sticky and plastic; many fine and few medium roots; many fine to coarse pores; few fine threads of salts; slightly effervescent; moderately alkaline (pH 8.4); diffuse wavy boundary. (4 to 30 inches thick)
C2--24 to 46 inches; grayish brown (2.5Y 5/2) silty clay loam consisting of thin strata of silt loam and silty clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and fine granular structure; very hard, firm, sticky and plastic; common fine and few medium roots; common fine pores; few fine threads of salts; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (20 to 35 inches thick)
C3--46 to 60 inches; brown (10YR 5/3) silt loam consisting of thin strata of fine sandy loam and silty clay loam, dark brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine pores; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Blaine County, Montana; 2,490 feet west and 300 feet north of SE corner of sec. 21, T. 32 N., R. 23 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Control section - 35 to 60 percent clay and less than 15 percent sand that is coarser than very fine sand.
Soil phases - flooded; moderately wet saline; wet. The wet phases have a water table at depths of 36 to 60 inches.
Ap horizon - Hue: 10YR or 2.5Y
Value: 4, 5, or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Textures: loam, silt loam, silty clay loam, clay loam, silty clay, or clay
Clay content: 20 to 55 percent
EC: 0 to 8 mmhos/cm; the saline phase is 4 to 8 mmhos/cm
SAR: 0 to 8
Effervescence: slightly or strongly
Reaction: pH 6.6 to 8.4
Some pedons have a thin dark colored surface about 4 inches thick that has values of 4 or 5 dry, 3 moist, and chroma of 2 or 3.
C1 horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Textures: clay, silty clay, or silty clay loam consisting of stratified layers of clay, silt loam, silty clay loam, and silty clay
Clay content: 35 to 60 percent
EC: 0 to 16 mmhos/cm; the saline phase is 4 to 16 mmhos/cm
SAR: 0 to 30; saline phase is 13 to 30
Effervescence: strongly or violently
Reaction: pH 7.4 to 9.0
C2 horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay, silty clay, or silty clay loam consisting of stratified layers of clay, silt loam, silty clay loam, and silty clay
Clay content: 35 to 60 percent
EC: 0 to 16 mmhos/cm; the saline phase is 4 to 16 mmhos/cm
SAR: 0 to 30; saline phase is 13 to 30
Effervescence: strongly or violently
Reaction: pH 7.4 to 9.0
C3 horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: silt loam, loam, clay loam, or fine sandy loam consisting of stratified layers of silty clay loam, silt loam, and fine sandy loam
Clay content: 15 to 35 percent
EC: 4 to 16 mmhos/cm; saline phase is 8 to 16 mmhos/cm
SAR: 0 to 30; saline phase is 13 to 30
Effervescence: strongly or violently
Reaction : pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Harlem soils are on flood plains. Elevations are 1,900 to 4,000 feet. Slopes are 0 to 4 percent. These soils formed in stratified clayey, calcareous alluvium. The climate is characterized by long, cold winters; moist springs; and hot, dry summers. The mean annual precipitation is 10 to 14 inches, most of which falls in the spring and early part of summer. Mean annual temperature is 40 to 45 degrees F. The frost-free period is 105 to 135 days. In Colorado elevations are 6,000 to 6,800 feet and the frost free period is 75 to 95 days.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; slow or very slow permeability.
USE AND VEGETATION: Harlem soils are used for irrigated and nonirrigated cropland. Some areas are used for range. The potential native vegetation is mainly green needlegrass, bluebunch wheatgrass, western wheatgrass, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Harlem soils are extensive in the plains area of Montana and Colorado and possibly the adjacent states.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Soil Survey of Milk River Area, Montana, 1928.
REMARKS: Soil interpretation records: MT0101, MT0186, MT0187, MT0232, MT1008.
Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 7 inches (Ap horizon); soil horizons that are calcareous from the soil surface to 60 inches (Ap, C1, C2, C3 horizons); stratification of soil material (C1, C2, C3 horizons); a particle-size control section from 10 to 40 inches (C1, C2 horizons). Harlem soils have a frigid temperature regime and an aridic moisture regime bordering on ustic.
Type location should be moved to an area considered to have an aridic moisture regime that borders on ustic. Blaine County is considered to have an ustic moisture regime that borders on aridic.
ADDITIONAL DATA: Laboratory sample S74MT-105-1, S51MT-85-2.