LOCATION WEASH IDEstablished Series
TAXONOMIC CLASS: Ashy, glassy, mesic, shallow Vitrixerandic Haplocambids
TYPICAL PEDON: Weash gravelly sandy loam--on a slope of 3 percent under rnageland vegetation at 5600 feet elevation. When described on September 11, 1978, the soil was slightly moist to 12 inches and dry below. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; pale brown (10YR 6/3) gravelly sandy loam, dark brown (10YR 4/3) moist; strong coarse platy structure; slightly hard, friable; many very fine, fine, medium and common coarse roots; many very fine and fine vesicular pores; 20 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (1 to 5 inches thick)
Bw1--2 to 8 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; many very fine, fine, medium and common coarse roots; many very fine and fine tubular pores; neutral (pH 7.0); clear smooth boundary. (5 to 10 inches thick)
Bw2--8 to 12 inches; brown (10YR 5/3) clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine to coarse roots; 80 percent weakly consolidated welded ash fragments 1/4 to 4 inches in diameter, oriented in the same direction as the parent material; neutral (pH 7.2); clear wavy boundary. (4 to 7 inches thick)
Cr--12 to 60 inches; white (10YR 8/2) weakly consolidated welded ash, light gray (10YR 7/2) moist; strong very coarse platy geologic structure; plates dipping downslope at a 5 percent slope; root matting between plates; top of plates strongly effervescent, matrix of plates noncalcareous.
TYPE LOCATION: Twin Falls County, Idaho; about 13 miles south of Rogerson, Idaho; southwest 1/4, southeast 1/4, northwest 1/4, sec. 13, T. 16 S., R. 15 E.
RANGE IN CHARACTERISTICS:
Depth to weakly consolidated ash - 10 to 20 inches
Average annual soil temperature - 47 to 50 degrees F
A horizon
Value - 5 to 7 dry, 3 or 4 moist
Chroma - 2 to 4 dry or moist
Gravel - 5 to 30 percent
Reaction (pH) - neutral or mildly alkaline
Bw horizons
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 to 4 dry or moist
Texture - SCL, CL, or L
Clay percent - 20 to 30
Reaction (pH) - neutral to moderately alkaline
COMPETING SERIES: There are no series in the same family. Grina soils are closely related but are not in an Ashy family.
GEOGRAPHIC SETTING: Weash soils occur on foothills and terraces. Slopes range from 1 to 35 percent. The soils formed in residuum and eolian material from volcanic ash. Elevations are 4,500 to 5,700 feet. The average annual precipitation ranges from 10 to 13 inches. The average annual temperature 45 to 48 degrees F. The frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chuska and Udaho soils. Chuska soils are on higher terraces, dipslopes and ridges and are shallow to a duripan. Udaho soils are on backslopes, footslopes and breaks and are skeletal and moderately deep to welded ash.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Weash soils are used mainly for rangeland and wildlife habitat. Dominant natural vegetation is western wheatgrass, bluebunch wheatgrass, Sandberg bluegrass, Indian ricegrass, arrowleaf balsamroot, Wyoming big sagebrush, and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Weash soils are of small extent in southern Idaho.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES PROPOSED: Twin Falls County, Idaho, 1978.
REMARKS: This draft changes the classification from a Xerollic Cabmorthids to a Vitrixerandic Camborthids based on Issue 13 amendments to SOIL TAXONOMY.
Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - 0 to 2 inches (A horizon)
Cambic horizon - 2 to 12 inches (Bw1 and Bw2 horizons)
Paralithic contact - at 12 inches (Cr horizon)