LOCATION SHEBANG IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Argialbolls
TYPICAL PEDON: Shebang silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; weak fine granular structure; very hard, slightly sticky and slightly plastic; few very fine roots; slightly acid (pH 6.2); abrupt smooth boundary. (4 to 7 inches thick)
A12--6 to 9 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry, weak fine and medium granular structure; very hard, slightly sticky and slightly plastic; common very fine roots; medium acid (pH 6.0); abrupt wavy boundary. (2 to 5 inches thick)
A2--9 to 10 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; massive; very hard, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; many iron and manganese concretions about 1 mm. in diameter; neutral (pH 6.8); abrupt wavy boundary. (1 to 2 inches thick)
IIB21t--10 to 23 inches; very dark gray (10YR 3/1) clay, very dark gray (10YR 3/1) dry; strong very coarse prismatic structure parting to strong medium and coarse angular blocky; extremely hard, very sticky and very plastic; common very fine roots; many very fine tubular pores; continuous thin clay films on surfaces of pores and common thin clay films on faces of peds; few iron and manganese concretions about 1 mm. in diameter; few small pressure faces oriented about 20 degrees from horizontal; mildly alkaline (pH 7.8); clear wavy boundary. (10 to 20 inches thick)
IIB22tca--23 to 36 inches; dark grayish brown (10YR 4/2) clay, dark grayish brown (10YR 4/2) dry; moderate very coarse prismatic structure parting to strong fine and medium angular blocky; extremely hard, very sticky and very plastic; few very fine roots; many very fine tubular pores; continuous thin clay films on surfaces of pores and common thin clay films on faces of peds; few iron and manganese concretions about 1 mm. in diameter; few organic coatings on faces of peds; many slickensides and wedge-shaped aggregates that are oriented about 45 degrees from horizontal, some intersect; large pockets of lime; noncalcareous matrix; strongly alkaline (pH 8.6); gradual wavy boundary.
IIB23tca--36 to 46 inches; brown (10YR 5/3) clay, brown (10YR 5/3) dry; weak very coarse prismatic structure parting to fine and medium angular blocky; very hard, few very fine roots; many very fine tubular pores; continuous thin clay films on surfaces of pores; large pockets of lime; noncalcareous matrix; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 11 inches thick)
IIB24tca--46 to 55 inches; dark brown (10YR 4/3) clay, brown (10YR 5/3) dry; strong fine and medium angular blocky structure; very hard, very firm, few very fine roots; many very fine roots; many very fine roots; many very fine tubular pores; continuous thin clay films on surfaces of pores; large pockets of lime; noncalcareous matrix; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 11 inches thick)
IIB25ca--55 to 65 inches; dark brown (10YR 4/3) clay, brown (10YR 5/3) dry; moderate fine and medium subangular blocky structure; very hard, very firm, few very fine roots; many very fine tubular pores; continuous thin clay films on surfaces of pores; small pockets of lime; slightly calcareous matrix; strongly alkaline (pH 8.6).
TYPE LOCATION: Idaho County, Idaho; 75 feet south (of center of road) and 360 feet west of the northeast corner of the NW1/2 NE1/4 section 18, T30N., R.2E.
RANGE IN CHARACTERISTICS: Shebang soils are more than 60 inches deep. The soils are usually moist, but are dry between depths of 4 and 12 inches for 45 to 70 consecutive days in late summer. The mean annual soil temperature ranges from 47 degrees to 50 degrees F. and the mean summer soils temperature ranges from 60 degrees to 65 degrees F. The mollic epipedon is 7 to 12 inches thick, depth to the clayey B2t horizon is 8 to 25 inches, and the solum is more than 48 inches thick. Depth to secondary lime ranges from 20 to 30 inches. The albic horizon contains iron and manganese concretions which are dominantly less than 2 mm. in diameter, but however, they are usually below the albic horizon.
The Ap horizon, or the mixed upper 7 inches, has value of 2 or less moist and 3 or 4 dry.
The A2 horizon has value of 2 through 4 moist and 5 or 6 dry. It is silt loam or loam.
The B21t horizon has hue of 10YR or 2.5Y, value of 2 or 3 moist, 3 or 4 dry, and chroma of 1 or 2. The upper 20 inches of the B2t horizons is silty clay or clay and has less than 60 percent clay.
COMPETING SERIES: These are the Chicane, Conley, Kooskia, Nez Perce and Tilma series. Chicane soils have mollic epipedons more than 20 inches thick. Conley soils are somewhat poorly drained and do not have secondary lime. Kooskia and Tilma soils lack chroma of 2 or less and other characteristics associated with wetness, such as mottles and concretions in the albic horizons. Nez Perce soils have mollic epipedons 12 to 20 inches thick, have iron-manganese concretions larger than 2 mm. in the albic horizon and above depth of about 40 inches.
GEOGRAPHIC SETTING: Shebang soils are on nearly level to hilly loess-covered basalt plateaus at elevations of 2,800 to 4,000 feet. Slopes are 0 to 25 percent. The soils formed in loess and possibly residuum weathered from Columbia River Basalt in their lower horizons. The climate is subhumid with a mean annual precipitation of 19 to 24 inches. maximum precipitation is in May and June and minimum in July and August. The average frost-free season (32 degrees F.) is about 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fenn, Ferdinand, and Uhlorn soils and the competing Chicane and Nez Perce soils. Penn soils have clayey Ap or A1 horizons, and wide cracks that extend below 20 inches when dry. Ferdinand soils have bedrock at depths of 20 to 40 inches, and more than 35 percent rock fragments in their argillic horizons. Uhlorn soils lack A2 horizons.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium or rapid runoff; slow permeability.
USE AND VEGETATION: Most areas are cultivated. Winter wheat, winter peas, barley, hay and pasture are the principal crops. The natural vegetation is mainly Idaho fescue, bluebunch wheatgrass, geranium, lupine and camas.
DISTRIBUTION AND EXTENT: Northern Idaho. Series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Idaho County, Idaho, 1976.