LOCATION WILSONGULCH             ID

Established Series
REV. FRK/GHL/TM
12/2019

WILSONGULCH SERIES

The Wilsongulch series consists of deep and very deep, well-drained moderately permeable soils. They formed in ashy alluvium and residuum, modified by rock fragments of quartz latite, on steep, south-facing mesa sides and hillsides and have slopes of 20 to 60 percent. The average annual temperature is about 7.8 degrees C., and the average annual precipitation is about 360 mm.

TAXONOMIC CLASS: Ashy-skeletal, glassy, mesic Vitrandic Haploxerolls

TYPICAL PEDON: Wilsongulch very stony loam - range. On a 45 percent concave slope, southwest aspect, 1,680 meter elevation. (Colors are for air dry soil unless otherwise stated. This profile was described on August 29, 1979.)

A--0 to 18 cm; brown (10YR 4/3) very stony loam, dark brown (10YR 3/3) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine irregular pores; 10 percent stones, 10 percent cobbles, 25 percent gravel; slightly effervescent; moderately alkaline (pH 8.0 with phenol red); gradual smooth boundary. (5 to 23 cm thick)

Bw--18 to 36 cm; brown (10YR 5/3) extremely cobbly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic;; many very fine and few fine roots; many very fine tubular pores; 30 percent cobbles, 30 percent gravel); strongly effervescent; moderately alkaline (pH 8.2 with phenol red); clear wavy boundary. (13 to 20 cm thick)

Bk1--36 to 69 cm; very pale brown (10YR 8/2) very gravelly loam, pale brown (10YR 6/3) moist; massive; slightly hard, very friable, nonsticky andslightly plastic; common very fine roots; common very fine tubular pores; 20 percent cobbles, 30 percent gravel; strongly effervescent; moderately alkaline (pH 8.2 with phenol red); abrupt wavy boundary. (18 to 36 cm thick)

Bk2--69 to 152 cm; very pale brown (10YR 8/2) very cobbly sandy loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic;; common very fine roots; common very fine tubular pores; 15 percent cobbles and 20 percent gravel; strongly effervescent; moderately alkaline (pH 8.4 with phenol red); clear smooth boundary. (31 to 45 inches thick)

TYPE LOCATION: Cassia County, Idaho; about 7 miles south of Oakley, Idaho, about 2,300 feet east and 1,700 feet south of the northwest corner of sec. 5, T. 16 S., R. 22 E.; USGS Blue Hill 7.5-minute topographic quadrangle; latitude 42 degrees 03 minutes 53.9 seconds N and longitude 113 degrees 54 minutes 11.9 seconds W, WGS84 Decimal Degrees 42.0649722 latitude, -113.9033056 longitude.

RANGE IN CHARACTERISTICS:
Average Annual soil temperature - 8.3 to 10.0 degrees C.
Soil Moisture: This soil is usually moist but dry for 45 to 70 consecutive days during the late summer and autumn. Typic xeric moisture regime.
Thickness of the Mollic epipedon - 18 to 36 cm.
Rock fragment content - 35 to 60 percent.
Reaction - with sodium fluoride - less than 9.5

A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3
Reaction - mildly to moderately alkaline

Bw horizons
Value - 5 or 6 dry, 2 or 3 moist
Chroma - 2 or 3
Texture - Very gravelly or very cobbly sandy loam.
Rock fragment content - 35 to 60 percent

Bk horizons
Hue - 10YR or 2.5Y
Value - 6 through 8 dry, 6 or 7 moist
Chroma - 2 through 4
Texture - Very gravelly, very cobbly or very stony loam or sandy loam.
Rock fragment content - 35 to 60 percent
Effervescence - strongly to violently

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Wilsongulch soils are on steep south-facing mesa sides and hillsides. Slopes range from 20 to 60 percent. Elevation ranges from 1,555 to 51,800 meters. The soils formed in alluvium and residuum from volcanic ash modified by rock fragments of quartz latite. The average annual precipitation is about 300 to 410 mm, the average annual air temperature is about 7.2 to 7.8 degrees C., and the frost-free season is 95 to 115 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coalbank, Bluehill, Cottonthomas and Tomsherry series and the Stines series. Bluehill soils are moderately deep to a paralithic contact. Coalbank, Cottonthomas, Stines and Tomsherry soils are frigid. Tomsherry soils have a duripan at a depth of 50 to 100 cm. Coalbank and Stines soils are on steep northerly slopes, Bluehill soils are on steep southerly slopes. Tomsherry soils are on fan terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderate to rapid runoff; moderate or moderately rapid saturated hydraulic conductivity.

USE AND VEGETATION: Wilsongulch soils are used for range. The natural vegetation is Wyoming big sagebrush, bluebunch wheatgrass, Indian ricegrass, Sandberg bluegrass and Nevada bluegrass.

DISTRIBUTION AND EXTENT: Wilsongulch soils are found in southern Idaho. They are not extensive. MLRA 25 and 11.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Cassia County, Idaho, 1986.

REMARKS:

Revision 3/2009 added geographic coordinates only.

Diagnostic horizons and features recognized in this pedon
are:
Mollic Epipedon - the zone from the surface to 28 cm (A and Bw horizons).
Control Section - 25 to 100 cm (Bw, Bk1 and part of the Bk2
horizons)
Andic feature - greater than 60 percent vitric material
Reaction with sodium fluoride - pH less than 9.5

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National Cooperative Soil Survey
U.S.A.