LOCATION PLUSH ID
Established Series
Rev. ALH/CLM
10/2019
PLUSH SERIES
The Plush series consists of deep, well drained soils that formed in colluvium and slope alluvium from welded rhyolitic tuff on sideslopes of foothills. Slopes are 25 to 50 percent. The average annual precipitation is about 280 mm and the average annual temperature is about 10.0 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Xeric Haplargids
TYPICAL PEDON: Plush very cobbly sandy loam -- on a northwest facing convex slope of 37 percent, in native rangeland, at 1,280 meter elevation. The surface has 10 to 15 percent cover of stones. (When described on September 4, 1980, the soil was slightly moist to 28 cm and dry below. Colors are for air dry soil unless otherwise stated.)
A--0 to 10 cm; pale brown (10YR 6/3) very cobbly sandy loam, brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine roots; many very fine interstitial pores; 25 percent gravel, 15 percent cobbles, 10 percent stones; neutral (pH 7.0); clear smooth boundary. (8 to 15 cm thick)
BA--10 to 28 cm; light yellowish brown (10YR 6/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular and interstitial pores; 20 percent gravel, 10 percent cobbles, neutral (pH 7.2); clear smooth boundary. (0 to 18 cm thick)
Bt--28 to 51 cm; light yellowish brown (10YR 6/4) very gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine tubular pores; many faint clay films on faces of peds and in pores; 35 percent gravel, 15 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary. (15 to 46 cm thick)
C--51 to 122 cm; very pale brown (10YR 7/4) extremely gravelly loam; dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine tubular pores; 40 percent gravel, 25 percent cobbles; slightly alkaline (pH 7.6); abrupt wavy boundary.
R--122 cm; fractured welded rhyolitic tuff.
TYPE LOCATION: Owyhee County, Idaho; about 27 miles east and 18 1/2 miles south of Silver City; 800 feet north and 1,800 feet west of the southeast corner of section 3, T. 8 S., R. 2 E.; USGS Purjue Canyon 7.5 minute topographic quadrangle; latitude 42 degrees 45 minutes 07 seconds N and longitude 116 degrees 11 minutes 48 seconds W; WGS84 Decimal Degrees 42.7519444 latitude, -116.1966667 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in the winter and spring, dry from late June through October; aridic soil moisture regime bordering on xeric.
Average annual soil temperature - 8.3 to 11.7 degrees C.
Depth to base of Bt horizon - 36 to 75 cm.
Depth to bedrock - 100 to 152 cm.
Bt horizon
Value - 5 or 6 dry
Chroma - 3 or 4 dry or moist
Texture - GRV-CL or CBV-CL
Clay - 27 to 35 percent
Rock fragments - 35 to 60 percent
Reaction (pH) - neutral or mildly alkaline
C horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - GRV-L, GRX-L, or CBX-L
Clay - 18 to 27 percent
Rock fragments - 50 to 85 percent
Reaction (pH) - neutral or mildly alkaline
COMPETING SERIES: These are the
Bairs,
Breko,
Cowgil,
Drino,
Hefed,
Hunewill,
Jungo,
Lithgow,
Stucky, and
Washoe series. The Bairs soils average 10 to 25 percent clay and more than 45 percent sand in the Bt horizon. The Breko soils have average annual soil temperature above 12.7 degrees C. Cowgil soils have secondary carbonates in the lower part of the Bt horizon or immediately below. Drino and Hefed soils average 18 to 27 percent clay in the particle-size control section and have average annual soil temperature of 52 to 55 degrees F. Hunewill soils average 18 to 27 percent clay in particle-size control section and less than 2 percent clay below 50 cm. Jungo soils are moderately or strongly alkaline and have secondary carbonates in the Bt horizon. Lithgow soils have a lithic contact at a depth of 50 to 100 cm. Stucky soils have more than 45 percent sand in the Bt horizon. Washoe soils are 80 to 114 cm deep to the base of the Bt horizon.
GEOGRAPHIC SETTING: Plush soils are steep on sideslopes of foothills, commonly below cliffs, and on landslide deposits at elevations of 915 to 1,605 meters. Slopes range from 25 to 50 percent. These soils formed in colluvium and slope alluvium from welded rhyolitic tuff and related extrusive rocks. The climate is cool and moist in the winter and hot and dry in the summer. Average annual precipitation is 250 to 330 mm, and average annual temperature is 7.2 to 11.1 degrees C. The frost-free period is 90 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Cottle and
Willhill soils. Cottle soils are less than 50 cm deep and on summits. Willhill soils are 50 to 100 cm deep and on gently sloping to moderately steep sideslopes.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; rapid runoff; moderately slow saturated hydraulic conductivity.
USE AND VEGETATION: Plush soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is Wyoming big sagebrush, bluebunch wheatgrass, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Southwestern Idaho. Plush soils are of moderate extent. MLRA 25.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Owyhee County Area, Idaho, 1992.
REMARKS: This draft changes the type location from Lake County, Oregon to Owyhee County, Idaho.
Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - The zone from the soils surface to 28 cm (the A and BA horizons).
Argillic horizon - The zone from 28 to 51 cm (The Bt horizon).
Lithic contact - The boundary at 122 cm (R boundary).
Particle-size control section - The zone from 28 to 51 cm (The Bt horizon).
National Cooperative Soil Survey
U.S.A.