LOCATION SHILLING IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerolls
TYPICAL PEDON: Shilling gravelly ashy loam, forested -- on a north-facing slope of 60 percent at 5,320 feet elevation. When described on September 28, 1994, the soil was dry throughout. (Colors are for air-dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed forest litter.
A--1 to 5 inches; dark grayish brown (2.5Y 4/2) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine, fine and medium, few coarse roots; many very fine, fine and medium irregular pores; 25 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (3 to 7 inches thick)
AB--5 to 10 inches; olive brown (2.5Y 4/3) gravelly ashy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure parting to weak medium granular; soft, very friable, nonsticky and slightly plastic; many very fine, fine and medium, few coarse roots; many very fine, fine and medium irregular pores; 25 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (0 to 6 inches thick)
Bw1--10 to 19 inches; light olive brown (2.5Y 5/3) very gravelly loam, dark olive brown (2.5Y 3/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine, fine and medium, few coarse roots; many very fine and fine irregular and tubular pores; about 75 percent of ped face covered by siltans; 35 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (5 to 10 inches thick)
Bw2--19 to 35 inches; light olive brown (2.5Y 5/4) very gravelly loam, olive brown (2.5Y 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine and fine, few medium and coarse roots; many very fine and fine irregular and tubular pores; about 25 percent of ped face covered by siltans; 45 percent gravel; slightly acid (pH 6.1); gradual wavy boundary. (10 to 20 inches thick)
Bw3--35 to 54 inches; light olive brown (2.5Y 5/4) very gravelly loam, olive brown (2.5Y 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine, few medium and coarse roots; many very fine, fine and medium tubular pores; about 10 percent of ped face covered by siltans; 40 percent gravel; slightly acid (pH 6.1); gradual wavy boundary. (10 to 20 inches thick)
Bw4--54 to 60 inches; light olive brown (2.5Y 5/4) very gravelly loam, olive brown (2.5Y 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; common very fine, fine and medium tubular pores; about 20 percent of ped face covered by siltans; 30 percent gravel, 5 percent cobbles; slightly acid (pH 6.1).
TYPE LOCATION: Boise County, Idaho; about 3 miles south and 1 mile east of Banks; 700 feet north and 2,350 feet west of the southeast corner of section 16, T.8 N., R.3 E.; USGS Banks Quadrangle; Latitude - 44 degrees, 01 minute, 30 seconds N. and Longitude - 116 degrees, 06 minutes, 27 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 10 to 20 inches
Depth to bedrock - greater than 60 inches
Reaction - moderately acid or slightly acid
Base saturation - 50 to 75 percent in the zone from 10 to 30 inches
Particle-size control section - 18 to 27 percent clay; 35 to 60 percent rock fragments
Moisture control section - dry 45 to 75 consecutive days following the summer solstice
Average annual soil temperature - 42 to 47 degrees F.
A horizon
Hue - 10YR or 2.5Y
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 10 to 15 percent
Rock fragments - 15 to 35 percent gravel
Volcanic glass content - 5 to 20 percent
Acid oxalate extract A1+1/2 Fe - 0.4 to 1.2 percent
Bw horizon
Hue - 10YR or 2.5Y
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Clay content - 18 to 27 percent
Rock fragments - 0 to 40 percent cobbles, 30 to 55 percent gravel and 35 to 75 percent total
COMPETING SERIES: These are the Bearspring, Cassal, Cherrycreek, Eastpine, Egyptcreek, Fredonyer, Longs, Midpeak, Mineral, Peahke, Piersonte, Scoap, Shalrock, Umatilla and Yellcreek series. Bearspring, Cherrycreek, Eastpine, Midpeak, Mineral, Scoap, Shalrock and Yellcreek have less than 18 percent clay in the particle-size control section. Cassal soils are moderately well drained with distinct redox features at 30 to 45 inches. Eastpine, Egyptcreek, Fredonyer, Midpeak, Mineral, Peahke and Shalrock soils are moderately deep to a lithic contact. Longs soils are 40 to 60 inches deep and have mollic epipedons greater than 20 inches thick. Piersonte soils have mollic epipedons 20 to 35 inches thick and have a pscs dominated by channer shaped rock fragments of shale origin. Umatilla soils have mollic epipedons greater than 20 inches thick and average 25 to 35 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Shilling soils are on mountain slopes at elevations of 3,800 to 6,700 feet. These soils formed in colluvium from basalt mixed with volcanic ash in the upper part. Slopes range from 15 to 65 percent. The average annual precipitation is 26 to 36 inches. The average annual temperature is 40 to 45 degrees F. The frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Highvalley and Hoff soils. Highvalley soils are fine-loamy and on similar geomorphic positions. Hoff soils are shallow to bedrock on convex hilltops and ridges.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Shilling soils are used mainly for timber production and woodland grazing. Native vegetation is Douglas-fir, ponderosa pine, grand fir, mallow ninebark and mountain maple.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 43b. Shilling 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 mineral soil surface to 19 inches. (A, AB and Bw1 horizons)
Vitrandic feature - zone from the mineral soil surface to 10 inches (A and AB horizons)
Cambic horizon - zone from 19 to 60 inches (Bw2, Bw3 and Bw4 horizons)
Particle-size control section - zone from 11 to 41 inches
Soil moisture regime - xeric
All depths related to diagnostic horizons and features listed in the range of characteristics are measured from the top of the first mineral horizon.