LOCATION WHISK IDEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic Lithic Ultic Haploxerolls
TYPICAL PEDON: Whisk fine gravelly sandy loam -- on a south-facing slope of 14 percent at 4,300 feet elevation in rangeland. When described on May 11, 1992, the soil was moist throughout. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 3 inches: brown (10YR 5/3) fine gravelly sandy loam, dark brown (10YR 3/3) moist; moderate fine platy structure parting to weak coarse granular; soft, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine and fine irregular pores; 20 percent fine gravel; moderately acid (pH 6.0); clear wavy boundary. (2 to 7 inches thick)
Bw1--3 to 11 inches; brown (10YR 5/3) fine gravelly sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; few very fine and fine roots; common very fine and fine irregular and tubular pores; 15 percent fine gravel; moderately acid (pH 5.8); gradual wavy boundary. (4 to 10 inches thick)
Bw2--11 to 14 inches; yellowish brown (10YR 5/4) fine gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine and fine roots; common very fine and fine irregular and tubular pores; 20 percent fine gravel; moderately acid (pH 5.8); gradual wavy boundary. (0 to 5 inches thick)
R--14 inches; unweathered granodiorite.
TYPE LOCATION: Boise County, Idaho; about 9 miles north and 2 miles west of Horseshoe Bend; 200 feet north and 2,400 feet west of the southeast corner of section 4, T.8 N., R.2 E.; USGS Dry Buck Valley Quadrangle; Latitude - 44 degrees, 03 minutes, 09 seconds N. and Longitude - 116 degrees, 13 minutes, 28 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 7 to 12 inches
Depth to bedrock - 10 to 20 inches
Base saturation - 50 to 75 percent
Reaction - moderately acid or slightly acid
Particle-size control section - 6 to 12 percent clay; 15 to 35 percent rock fragments
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 52 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Rock fragments - 15 to 35 percent gravel
Bw horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Texture - SL or COSL
Clay content - 6 to 12 percent
Rock fragments - 0 to 5 percent cobbles, 15 to 30 percent gravel, and 15 to 35 percent total
C horizon - may occur in some pedons
COMPETING SERIES: These are the Dobson, McMullin and Reston series. Dobson soils are moist less than 90 consecutive days when the soil temperature is greater than 47 degrees F. (aridic bordering on xeric soil moisture regime). McMullin soils have 20 to 35 percent clay in the Bw horizon and are dry for more than 90 consecutive days following the summer solstice. Reston soils are 5 to 10 inches deep to hard bedrock.
GEOGRAPHIC SETTING: Whisk soils are strongly sloping to very steep on mountain slopes, canyon walls, and hill summits, shoulders and backslopes at elevations of 3,000 to 5,650 feet. These soils formed in colluvium and residuum from granitic rocks. Slopes range from 8 to 90 percent. The average annual precipitation is 14 to 26 inches. The average annual temperature is 45 to 50 degrees F. The frost-free period is 90 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brownlee, Drybuck, Kisky, Robbscreek and Roney soils. Brownlee and Drybuck soils are deep and on concave or lower footslopes. Kisky soils are sandy-skeletal and on similar geomorphic positions. Robbscreek and Roney soils are moderately deep to bedrock and on similar geomorphic positions.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Whisk soils are used mainly for rangeland and wildlife habitat. Native vegetation is xeric big sagebrush, bluebunch wheatgrass, antelope bitterbrush and commonly scattered ponderosa pine.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10 and 43b. Whisk soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the soil surface to 11 inches (A and Bw1 horizons)
Particle-size control section - zone from 10 to 14 inches (or the whole pedon the depth to R is less than 14 inches)
Cambic horizon - zone from 11 to 14 inches (Bw2 horizon)
Lithic contact - at 14 inches (R)
Soil moisture regime - xeric