LOCATION NILER MTEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Gypsic Haplustepts
TYPICAL PEDON: Niler silty clay loam, grassland (colors are for dry soil unless otherwise noted).
A--0 to 3 inches; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; weak fine platy structure parting to moderate fine granular; slightly hard, firm, sticky and plastic; common very fine roots; common very fine pores; disseminated lime; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 4 inches thick)
By--3 to 13 inches; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, firm, sticky and plastic; common very fine roots; few fine pores; 70 percent fine soft shale fragments; common fine nests of gypsum; disseminated lime; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 16 inches thick)
Cr--13 to 60 inches; semiconsolidated shale that crushes to silty clay loam; few very fine roots in cracks; moderately alkaline (pH 8.0).
TYPE LOCATION: Rosebud County, Montana; 100 feet north and 1,800 feet east of the SW corner of sec. 17, T. 9 N., R. 39 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 when the soil temperature at a depth of 20 inches is 41 degrees F. The soil has a ustic moisture regime that borders on aridic.
Depth to By horizon - 2 to 4 inches.
Depth to semiconsolidated shale - 10 to 20 inches.
Some pedons have a C horizon above the By horizon.
A horizon - Texture: clay loam or silty clay loam
Clay content: 27 to 35 percent
EC: 2 to 4 mmhos/cm
Reaction: pH 7.9 to 8.4
Cy horizon - Texture: clay loam or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 50 to 80 percent soft shale fragments
EC: 2 to 4 mmhos/cm
SAR: 3 to 10
Gypsum: 5 to 18 percent
Reaction: pH 7.9 to 8.4
Cr horizon - EC: 8 to 20 mmhos/cm
SAR: 1 to 10
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series. (The Cabbart soils do not have a horizon of gypsum accumulation.)
GEOGRAPHIC SETTING:
Landform - sedimentary plains; hills.
Elevation - 2,700 to 3,000 feet.
Slope- 2 to 35 percent.
Parent material - residuum derived from semiconsolidated shale.
Climate - long, cold winters; moist springs; hot summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 100 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Niler soils are used mainly for rangeland. Potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, needleandthread, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Niler soils are of limited extent in southeastern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Rosebud County, Montana, 1985. The name is that of an abandoned town in northern Rosebud County.
REMARKS: Soil interpretations record: MT0585. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 7 inches, mixed (A, By horizons); a gypsic horizon from 3 to 13 inches (By horizon); a paralithic contact at a depth of 13 inches (Cr horizon). Niler soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.
ADDITIONAL DATA: Laboratory sample S77MT-087-436.