LOCATION PINNEY IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Vitrandic Argixerolls
TYPICAL PEDON: Pinney ashy silt loam, forested -- on a 17 percent slightly concave north-facing slope at 3,380 feet elevation. When described on October 20, 1997, the soil was moist to 8 inches and dry below. (Colors are for air-dry soil unless otherwise noted.)
Oi--0 to 2 inches; slightly decomposed forest litter.
A1--2 to 5 inches; dark grayish brown (10YR 4/2) ashy silt loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine and fine irregular pores; 5 percent fine gravel; slightly acid (pH 6.3); clear smooth boundary.
A2--5 to 13 inches; grayish brown (10YR 5/2) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine and fine irregular pores; 5 percent fine gravel; slightly acid (pH 6.3); clear wavy boundary. (combined A horizon - 8 to 20 inches thick)
2Bt1--13 to 23 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; few distinct clay films on faces of peds and in pores; 5 percent fine gravel; slightly acid (pH 6.1); clear wavy boundary. (6 to 14 inches thick)
2Bt2--23 to 30 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; strong fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 5 percent fine gravel; slightly acid (pH 6.1); abrupt smooth boundary. (0 to 12 inches thick)
2Bt3--30 to 49 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 3/4) moist; strong fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common few very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 5 percent fine gravel; moderately acid (pH 6.0); gradual wavy boundary. (8 to 24 inches thick)
2Bt4--49 to 60 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; few very fine, fine, medium and coarse roots; common very fine and fine, few medium tubular pores; few distinct clay films in pores; light yellowish brown (10YR 6/4) discontinuous lamella 2 to 5 mm thick; 5 percent gravel; moderately acid (pH 5.7).
TYPE LOCATION: Boise County, Idaho; about 3 miles north of Crouch; 2,100 feet north and 750 feet west of the southeast corner of section 28, T.10 N., R.4 E.; USGS Pyle Creek Quadrangle; Latitude - 44 degrees, 10 minutes, 08 seconds N. and Longitude - 115 degrees, 58 minutes, 47 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 20 to 40 inches
Depth to base of argillic horizon - 40 to 60 inches or more
Depth to bedrock - 60 inches or more
Base saturation - 50 to 75 percent
Reaction - moderately acid or slightly acid
Particle-size control section - 20 to 32 percent clay; 0 to 15 percent rock fragments; greater than 30 percent fine sand or coarser
Moisture control section - dry 45 to 75 consecutive days following the summer solstice
Average annual soil temperature - 44 to 47 degrees F.
A horizon
Hue - 7.5YR or 10YR
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture ASHY-SIL or ASHY-L
Clay content - 15 to 24 percent
Rock fragments - 0 to 5 percent gravel
Volcanic glass content - 5 to 20 percent
Acid oxalate extract Al+1/2Fe - 0.4 to 1.0 percent
2Bt horizon
Hue - 7.5YR or 10YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - L, SCL or CL
Clay content - 20 to 32 percent
Rock fragments - 0 to 35 percent gravel with less than 15 percent in the upper part
Lamellae (lower part) - 2 to 10 mm thick; 2 to 15 inches apart
2E&Bt horizons are present in the lower part of some pedons
COMPETING SERIES: These are the Luckycreek (T), Powellbutte (T), and Runyon series. Luckycreek soils are dry for 75 to 100 consecutive days and have secondary carbonates at 25 to 40 inches. Powellbutte soils are 20 to 40 inches deep to a lithic contact. Runyon soils are 20 to 40 inches to a paralithic contact. The Hess, Lidos, Melhorn, Raycreek (T), Salcreek (T) and Tourn series are similar, but have isotic mineralogy. Hess soils are 40 to 60 inches deep. Hess, Lidos, Melhorn, Raycreek and Salcreek soils have mollic epipedons less than 20 inches thick. Raycreek and Tourn soils are less than 40 inches deep.
GEOGRAPHIC SETTING: Pinney soils are moderately steep to very steep on dissected fan remnants, outwash terrace remnants and lower mountain slopes at elevations of 3,050 to 4,800 feet. These soils formed in lacustrine deposits derived from igneous rocks and fine pyroclastic materials with the upper part having more recent additions of volcanic ash. Slopes range from 15 to 65 percent. Average annual precipitation is 26 to 30 inches. Average annual temperature is 42 to 45 degrees F. Frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Charters, Middlefork, Shirts and Zeb soils. Charters, Shirts and Zeb soils do not have argillic horizons or pachic epipedons and occur on convex summits or south-facing slopes. Middlefork soils do not have pachic epipedons and occur on less steep slopes.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Pinney soils are used mainly for timber production and woodland grazing. Some areas are used for homesites. Native vegetation is grand fir, Douglas-fir, ponderosa pine, white spirea, mountain maple and mallow ninebark.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 44 and 43b. Pinney soils are of small extent.
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 mineral soil surface to 30 inches (A1, A2, 2Bt1 and 2Bt2 horizons)
Vitrandic feature - zone from 2 to 13 inches (A1 and A2 horizons)
Argillic horizon - zone from 16 to 60 inches (2Bt1, 2Bt2, 2Bt3 and 2Bt4 horizons)
Particle-size control section - zone from 13 to 33 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.
ADDITIONAL DATA: This pedon has partial laboratory analysis, reference sample no. S98ID-015-004 (Pedon no. 99P60), NSSL, Lincoln, NE.