LOCATION RHAME ND+MN MT SDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aridic Haplustolls
TYPICAL PEDON: Rhame fine sandy loam - under grassland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 3 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable; many very fine roots, almost matted; neutral; clear wavy boundary.
A2--3 to 8 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium and fine subangular blocky structure; slightly hard, very friable; many very fine roots; neutral; gradual wavy boundary. (Combined A horizons 5 to 14 inches thick)
Bw--8 to 19 inches; brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; weak coarse prismatic structure parting to weak coarse and medium subangular blocky; slightly hard, very friable; many fine roots; neutral; gradual wavy boundary. (6 to 12 inches thick)
BC--19 to 26 inches; light yellowish brown (2.5Y 6/4) fine sandy loam, olive brown (2.5Y 4/4) moist; weak coarse prismatic structure parting to weak coarse and medium subangular blocky; slightly hard, very friable; common very fine roots; neutral; clear wavy boundary. (7 to 14 inches thick)
C--26 to 34 inches; pale yellow (2.5Y 7/3) fine sandy loam, light olive brown (2.5Y 5/4) moist; weak coarse and medium subangular blocky structure; hard, very friable; common very fine roots; few fine specks of carbonates; slight effervescence; moderately alkaline; clear wavy boundary.
Cr--34 to 60 inches; pale yellow (5Y 7/3) very soft bedded sandstone, olive (5Y 5/3) moist; massive; slightly hard and hard in strata and brittle when dry, very friable; strong effervescence.
TYPE LOCATION: Bowman County, North Dakota; 2,030 feet north and 260 feet east of the southwest corner, sec. 16, T. 131 N., R. 106 W.
RANGE IN CHARACTERISTICS: The depth to soft sandstone ranges from 20 to 40 inches. The depth to carbonates ranges from 10 inches to 30 inches, except where the soil formed in sandstone low in carbonates. The control section typically is fine sandy loam or sandy loam. The mollic epipedon ranges from 7 to 14 inches thick.
The A horizon has hue of 10YR, value of 4 or 5 and 3 moist, and chroma of 2 or 3. It is fine sandy loam or sandy loam. It is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6, 3 to 5 moist, and chroma of 2 to 4. It is fine sandy loam or sandy loam. It is neutral or slightly alkaline.
The C horizon typically contains carbonates and has slight to strong effervescence. It is fine sandy loam or sandy loam. It is neutral to moderately alkaline. Some pedons are free of carbonates in the C horizon.
COMPETING SERIES: These are the Chinook, Cozberg, Pring and Tinytown series. The Chinook, Cozberg and Pring soils do not have paralithic contacts within depths of 40 inches. Tinytown soils have hue of 2.5YR or redder and are gravelly.
GEOGRAPHIC SETTING: Rhame soils are on level to very steep uplands. The slope gradient ranges from 0 to 70 percent. The soils formed in calcareous, residuum weathered from soft sandstone. A mean annual temperature is 38 to 45 degrees F, and mean annual precipitation of 10 to 16 inches, more than 70 percent of which falls in the spring and summer. Frost-free period ranges from 110 to 130 days and elevation ranges from 1900 to 5200 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Chinook soils and the Fleak, Marmarth and Tusler soils. Chinook soils are on the foot slopes. Fleak soils are on steeper sideslopes and knobs. They have a paralithic contact within a depth of 20 inches. Marmarth soils are fine-loamy and have an argillic horizon. They are on similar but more stable positions. Tusler soils are on similar positions. They are sandy.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium Permeability is moderately rapid.
USE AND VEGETATION: Small grains, mainly spring wheat are raised in a crop-summerfallow rotation. Grassland is used for hay and pasture. Native vegetation is medium and short prairie grasses as blue grama, needleandthread and upland sedges.
DISTRIBUTION AND EXTENT: Southwestern North Dakota, northwestern South Dakota, and possibly eastern Montana. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Bowman County, North Dakota, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 8 inches (A1 and A2 horizons); cambic horizon - the zone from 8 to 19 inches (Bw horizon); aridic subgroup criteria - color value dry, of more than 4.5 in the upper 7 inches (A1 and A2 horizons).