LOCATION DRYBUCK IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Pachic Ultic Haploxerolls
TYPICAL PEDON: Drybuck sandy loam, forested -- on a southwest-facing slope of 60 percent at 4,680 feet elevation. When described on October 25, 1993, the soil was slightly moist throughout. (Colors are for air-dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed forest litter.
A1--1 to 7 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse platy structure parting to moderate fine and medium granular; soft, very friable, nonsticky and slightly plastic; many very fine and fine, common medium roots; many very fine, fine and medium irregular and tubular pores; 10 percent fine gravel; moderately acid (pH 5.6); clear wavy boundary.
A2--7 to 15 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, few medium roots; many very fine, fine and medium irregular and tubular pores; 10 percent fine gravel; slightly acid (pH 6.1); gradual wavy boundary. (combined A horizon - 10 to 20 inches thick)
AB--15 to 31 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, few medium roots; many very fine, fine and medium irregular and tubular pores; 10 percent fine gravel; slightly acid (pH 6.5); abrupt wavy boundary. (10 to 20 inches thick)
Bw1--31 to 43 inches; brown (10YR 5/3) fine gravelly sandy loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, few medium roots; many very fine and fine tubular pores; 20 percent fine gravel; neutral (pH 6.6); gradual wavy boundary.
Bw2--43 to 53 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine, fine and medium roots; many very fine and fine tubular pores; 10 percent fine gravel; neutral (pH 6.6); abrupt wavy boundary. (combined Bt horizon - 20 to 40 inches thick)
R--53 inches; unweathered granodiorite.
TYPE LOCATION: Boise County, Idaho; about 10 miles north of Horseshoe Bend; 1,600 feet north and 1,400 feet west of the southeast corner of section 34, T.9 N., R.2 E.; USGS Dry Buck Valley Quadrangle; Latitude - 44 degrees, 04 minutes, 13 seconds N and Longitude - 116 degrees, 12 minutes, 02 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 45 inches
Depth to bedrock - 40 to 60 inches
Reaction - moderately acid to neutral
Base saturation - 50 to 75 percent in some part between 10 and 30 inches
Particle-size control section - 8 to 15 percent clay; 0 to 25 percent rock fragments
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 50 degrees F.
A horizon
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 1 to 3 dry or moist
Rock fragments - 0 to 15 percent gravel
AB horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Texture - sandy loam or coarse sandy loam
Clay content - 7 to 15 percent
Rock fragments - 0 to 15 percent gravel
Bw horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 to 4 dry or moist
Texture - sandy loam or coarse sandy loam
Clay content - 8 to 15 percent
Rock fragments - 0 to 35 percent gravel
COMPETING SERIES: These are the Ben Lomond, Junipero, Olaton, and Pigtoe (T) series. Ben Lomond soils are deep over a weathered sandstone paralithic contact and have mean annual soil temperature of about 56 degrees F. Junipero soils are moderately deep to a paralithic contact, do not have B horizons and have mean annual soil temperature of 54 to 58 degrees F. Olaton soils are deep over a paralithic contact and do not have an O horizon. The Pigtoe series is not currently in the OSD database and cannot be adequately competed.
GEOGRAPHIC SETTING: Drybuck soils are on mountain slopes and canyon walls at elevations of 2,750 to 6,250 feet. These soils formed in colluvium and residuum from granitic rocks. Slopes range from 8 to 90 percent. The average annual precipitation is 20 to 26 inches. The average annual temperature is 45 to 48 degrees F. The frost-free period is 90 to 125 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Deerrun, Kisky, Northfork and Whisk soils. Deerrun soils are moderately deep to bedrock and are on similar geomorphic positions. Northfork soils are very deep and are on footslopes and concave backslopes. Kisky and Whisk soils are shallow to bedrock and are on convex summits, shoulders and backslopes.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Drybuck soils are used mainly for timber production, woodland grazing and wildlife habitat. Native vegetation is ponderosa pine, bluebunch wheatgrass, antelope bitterbrush and common snowberry.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 43B. Drybuck soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
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 mineral soil surface to 53 inches (A1, A2, AB, Bw1 and Bw2 horizons)
Particle-size control section - zone from 11 to 41 inches
Lithic contact - at 53 inches (R)
Soil moisture regime - xeric
All depths to diagnostic horizons and features within the range of characteristics are measured from the top of the first mineral horizon.