LOCATION BOLES IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Xeric Argialbolls
TYPICAL PEDON: Boles silt loam, in a cultivated field on a 2 percent slope at 4,100 feet elevation. When described on September 7, 1972, the soil was moist throughout. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 5 inches; dark grayish brown (10YR 4/2) silt loam, black (10YR 2/1) moist; moderate fine and medium granular structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; slightly acid (pH 6.3); abrupt smooth boundary. (4 to 7 inches thick)
A--5 to 9 inches; very dark grayish brown (10YR 3/2) silt loam, black (10YR 2/1) moist; weak medium subangular blocky structure parting to weak fine and medium granular; very hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine and medium tubular pores; neutral (pH 6.6); clear wavy boundary. (3 to 7 inches thick)
Bw--9 to 14 inches; dark brown (10YR 4/3) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine and medium tubular pores; few iron and manganese concretions up to 3 mm. in diameter; slightly acid (pH 6.4); abrupt wavy boundary. (3 to 7 inches thick)
E--14 to 19 inches; light gray (10YR 7/2) silt loam, very dark grayish brown (10YR 4/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine tubular pores in upper part and few in the lower part; many iron and manganese concretions up to 4 mm. in diameter; neutral (pH 6.6); abrupt wavy boundary. (3 to 7 inches thick)
Btb1--19 to 25 inches; dark grayish brown (10YR 4/2) silty clay, dark grayish brown (10YR 4/2) moist; weak medium prismatic structure parting to strong fine and medium angular blocky; extremely hard, firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; common faint clay films on surface of peds and pores; some E material on faces of prisms; some interfingering in upper 2 inches; few basalt and quartz gravel; many iron and manganese concretions up to 3 mm.
i. diameter; more plastic than other horizons; few pressure faces; neutral (pH 6.6); clear wavy boundary. (4 to 8 inches thick)
Btb2--25 to 34 inches; brown (10YR 5/3) silty clay, dark brown (10YR 4/3) moist; strong fine and medium angular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; many faint clay films on surfaces of pores; some E material on faces of peds; few dark wavy horizontal bands; many pressure faces and wedge-shaped aggregates that intersect and are oriented 50 degrees from horizontal; few basalt and quartz gravel; many iron and manganese concretions up to 3 mm. in diameter; neutral (pH 6.9); gradual wavy boundary. (7 to 11 inches thick)
Btb3--34 to 50 inches; brown (10YR 5/3) silty clay, brown (10YR 5/3) moist; moderate medium angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many faint clay films on surfaces of pores; few pressure faces and wedge-shaped aggregates oriented 45 degrees from horizontal, some intersect; few basalt and quartz gravel; many iron and manganese concretions up to 3 mm. in diameter; neutral (pH 6.9); gradual wavy boundary. (12 to 18 inches thick)
Btb4--50 to 59 inches; brown (10YR 5/3) clay, brown (10YR 5/3) moist; strong fine and medium angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many faint clay films on surfaces of pores; about 1 percent weathered basalt gravel; many pressure faces and wedge-shaped aggregates that intersect and are oriented 50 degrees from horizontal; many iron and manganese concretions up to 3 mm. in diameter; neutral (pH 6.9); clear wavy boundary. (7 to 11 inches thick)
2Btb5--59 to 76 inches; multicolored very gravelly clay; strong fine angular blocky structure; very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many faint clay films on surfaces of pores; many iron and manganese concretions up to 3 mm. i. diameter; about 50 percent weathered basalt gravel and cobbles; few pressure faces and wedge-shaped aggregates oriented 45 degrees from horizontal, some intersect.
TYPE LOCATION: Idaho County, Idaho; about 5 miles southwest of Cottonwood; about 346 feet south and 1,260 feet west of the northeast corner of sec. 22, T. 31 N., R. 1 W. Latitude - 46 degrees, 01 minutes, 08 seconds North; Longitude - 116 degrees, 26 minutes, 08 seconds West; USGS Keuterville quadrangle.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 20 inches Organic matter content in the mollic epipedon (weighted average) - 3 to 6 percent Depth to the argillic horizon - 14 to 27 inches Depth to perched seasonal water table - 10 to 27 inches Depth to secondary carbonates - 40 to 60 inches or more Solum thickness - greater than 40 inches Depth to bedrock - greater than 60 inches Days dry, moisture control section - 45 to 60, in mid-July through mid-September Average annual soil temperature - 43 to 47 degrees F Average summer soil temperature - 59 to 63 degrees F
Particle-size control section (weighted average) Clay content - 35 to 55 percent
A horizon Value - 3 or 4 dry, 1 or 2 moist Chroma - 1 or 2, dry or moist Organic carbon content - 2.0 to 5.5 percent Reaction - strongly acid through neutral
E horizon Value - 6 or 7 dry, 4 or 5 moist Chroma - 1 or 2, dry or moist Clay content - 10 to 20 percent Reaction - slightly acid or neutral Contains few to many iron-manganese concretions as large as 4mm in diameter
Btb horizon, upper part Hue - 7.5YR or 10YR Value - 4 through 6 dry, 3 or 4 moist Chroma - 2 through 4, moist or dry Textures - clay or silty clay Clay content - 40 to 55 percent Gravel content - 0 to 15 percent Reaction - slightly acid or neutral
Btkb horizons are present in some pedons.
COMPETING SERIES: These are the Cowsly and Wilkins series. Cowsly soils lack cambic horizons and bisequa profiles, and have less than 2.0 percent organic carbon in the A horizon. Wilkins soils have faint to distinct mottles below a depth of 4 inches and are poorly or somewhat poorly drained.
GEOGRAPHIC SETTING: Boles soils are on plateaus and have gradients of 1 to 25 percent. They formed in loess and residuum weathered from Columbia river basalt or andesite, greenstone or similar rocks of the Seven Devils volcanics. Elevations are 3,500 to 4,500 feet. The average annual precipitation is 22 to 26 inches. The average annual temperature is about 41 degrees to 45 degrees F. The frost-free period is about 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the De Masters and Uptmor soils. Uptmor soils lack E horizons and De masters soils have fine-loamy Bt horizons.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium or rapid runoff; slow permeability.
USE AND VEGETATION: Cropland, rangeland and woodland. Soils are cropped to winter wheat, winter peas, oats and barley. Important native plants are ponderosa pine, common snowberry, rose, Idaho fescue, bluebunch wheatgrass, and blue wildrye.
DISTRIBUTION AND EXTENT: Boles soils are moderately extensive in the southwestern portion of northern Idaho. They may also occur in northeastern Oregon and southeastern Washington.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Idaho County, Idaho, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 14 inches (Ap, A, and Bw horizons).
Albic horizon - The zone from 14 to 19 inches (E horizon).
Argillic horizon - The zone from 19 to 76 inches (Btb1 through 2Btb5 horizons).
Particle-size control section - The zone from 19 to 39 inches (Btb1, Btb2, and part of the Btb3 horizon).