LOCATION RUEDLOFF COEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Ustic Haplargids
TYPICAL PEDON: Ruedloff loamy coarse sand-on a southwest facing slope of 6 percent in rangeland. (Colors for dry soil unless otherwise noted.)
A--0 to 2 inches; very pale brown (10YR 7/3) loamy coarse sand, pale brown (10YR 6/3) moist; weak medium platy structure parting to weak medium granular; soft, very friable, nonsticky and nonplastic; 5 percent fine gravel; slightly alkaline (pH 7.4); abrupt smooth boundary. (1 to 4 inches thick)
Bt1--2 to 12 inches; brown (7.5YR 5/4) coarse sandy loam, brown (7.5YR 5/4) moist; weak coarse subangular blocky structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common faint clay films on faces of peds; 5 percent fine gravel; slightly alkaline (pH 7.6); clear smooth boundary. (6 to 12 inches thick)
Bt2--12 to 19 inches; light brown (7.5YR 6/4) coarse sandy loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and nonplastic; few faint clay films on faces of peds; 5 percent fine gravel; slightly effervescent, moderately alkaline (pH 8.4); clear smooth boundary. (5 to 10 inches thick)
Bk1--19 to 24 inches; light yellowish brown (10YR 6/4) coarse sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; 5 percent fine gravel; common concentrations of calcium carbonate; violently effervescent, moderately alkaline (pH 8.4); gradual smooth boundary. (0 to 15 inches thick)
Bk2--24 to 48 inches; brownish yellow (10YR 6/6) loamy coarse sand, yellowish brown (10YR 5/6) moist; massive; soft, very friable, nonsticky and nonplastic; 5 percent fine gravel; common concentrations of calcium carbonate; strongly effervescent, moderately alkaline (pH 8.0); gradual smooth boundary. (5 to 25 inches thick)
C--48 to 60 inches; yellow (10YR 7/6) coarse sand, brownish yellow (10YR 6/6) moist; single grain; loose, nonsticky and nonplastic; 10 percent fine gravel; strongly effervescent, moderately alkaline (pH 8.0). (10 to 30 inches thick)
TYPE LOCATION: Moffat County, Colorado; 6 miles east of Powderwash; 2,500 feet west and 1,750 feet south of the northeast corner of Sec. 28, T. 12 N., R. 96 W. Reservoir Draw USGS quadrangle; Longitude: 108 degrees, 10 minutes, 50 seconds west. Latitude: 40 degrees, 58 minutes, 26 seconds north.
RANGE IN CHARACTERISTICS:
Soil moisture: aridic regime bordering on ustic.
Mean annual soil temperature ranges from 43 to 46 degrees F.
Mean summer soil temperature ranges from 60 to 63 degrees F.
Depth to calcareous material ranges from 7 to 30 inches.
Depth to the base of the argillic horizon ranges from 12 to 26 inches.
Rock fragments range from 0 to 15 percent throughout the soil and are mainly less than one inch in diameter.
A horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry and 4 through 6 moist
Chroma: 3 or 4
Bt horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry and 4 or 5 moist
Chroma: 4 through 6
Reaction: slightly alkaline or moderately alkaline
Texture: sandy loam or coarse sandy loam
Bk horizon
Hue: 10YR or 7.5YR
Value: 6 through 8 dry and 5 through 7 moist
Chroma: 4 through 6
Texture: coarse sandy loam, sandy loam, loamy coarse sand, or loamy sand
C horizon
Hue: 10YR or 7.5YR
Chroma: 4 through 6
COMPETING SERIES: These are the
Cotha,
Ryan Park, and
Ryark series.
Cotha soils have a paralithic contact.
Ryan Park soils do not have C horizons with sandy textures.
Ryark soils do not have horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING: Ruedloff soils are on hills, benches, and toe slopes and have slopes of 1 to 25 percent. The soils formed in coarse textured alluvium, residuum, and eolian deposits derived from sandstone. Parent materials are associated with Wasatch Formation. Mean annual precipitation ranges from 9 to 11 inches and is fairly evenly distributed throughout the year. June and July are the months of lowest precipitation during the growing season. The average annual temperature is 40 to 45 degrees F. The frost-free season is 75 to 95 days. Elevation ranges from 6,000 to 6,500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hiatha, Kandaly, and Simanni soils. Kandaly soils do not have an argillic horizon, are in a sandy family, and are on hillcrests. Hiatha soils are shallow to shale bedrock, are in a fine family, and are on hills. Simanni soils are in the fine-loamy family, and are on the same topographic position.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; low runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are used for rangeland. Native vegetation is Wyoming big sagebrush, shadscale, needleandthread, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Ruedloff soils occur in northwestern Colorado, MLRA 34A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado, 1991.
REMARKS: Diagnostic horizons recognized in this pedon:
Ochric epipedon - from 0 to 2 inches (A horizon)
Argillic horizon - from 2 to 24 inches (Bt1 and Bt2 horizons)
Particle-size control section - The zone from 2 to 22 inches (upper 20 inches of argillic horizon)
Series control section - The zone from 0 to 60 inches.
The 01/2007 revision changes the moisture regime subclass to ustic-aridic and the subgroup from Typic Haplargids to Ustic Haplargids.