LOCATION BISCHOFF IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic Pachic Argicryolls
TYPICAL PEDON: Bischoff silt loam, in rangeland, at 6,840 feet elevation. When described on September 8, 1995, the soil was dry throughout. (Colors are for air dry soil unless otherwise noted.)
A1--0 to 1 inches; brown (7.5YR 4/2) silt loam, very dark gray (7.5YR 3/1) moist; moderate medium and coarse granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine and few fine tubular and irregular pores; 5 percent gravel; slightly alkaline (pH 7.4); abrupt smooth boundary.
A2--1 to 4 inches; brown (7.5YR 4/2) silt loam, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine and few fine tubular and irregular pores; 5 percent gravel; neutral (pH 7.3); clear wavy boundary. (Combined thickness of the A horizons is 3 to 12 inches)
AB--4 to 16 inches; brown (7.5YR 4/3) silt loam, dark brown (7.5YR 3/2) moist; weak medium and coarse subangular blocky structure parting to moderate fine angular blocky; moderately hard, friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common very fine and few fine tubular and irregular pores; few patchy faint clay films on faces of peds and in pores; 5 percent gravel; neutral (pH 7.1); clear wavy boundary. (9 to 14 inches thick)
Bt1--16 to 29 inches; reddish brown (5YR 5/3) silty clay loam, dark reddish brown (5YR 3/3) moist; weak fine and medium prismatic structure parting to moderate fine and medium angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine, fine, and medium roots; few very fine and fine tubular pores; many continuous distinct clay films on faces of peds and in pores; common uncoated silt grains; 5 percent gravel; neutral (pH 7.1); clear wavy boundary. (4 to 14 inches thick)
Bt2--29 to 47 inches; reddish brown (5YR 5/3) silty clay loam, reddish brown (5YR 4/3) moist; moderate medium prismatic structure parting to moderate fine and medium subangular blocky; very hard, extremely firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many continuous prominent clay films on faces of peds and in pores; 5 percent gravel, 2 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (10 to 20 inches thick)
Bt3--47 to 61 inches; reddish brown (5YR 5/4) silty clay, reddish brown (5YR 4/3) moist; moderate medium and coarse subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many discontinuous prominent clay films on faces of peds and in pores; 5 percent gravel, 2 percent cobbles; slightly alkaline (pH 7.6).
TYPE LOCATION: Bear Lake County, Idaho; about 3 miles southwest of Geneva, ID; about 1,000 feet east and 400 feet south of the northwest corner of sec. 5, T.13S., R.46W. Latitude - 42 degrees, 19 minutes, 42 seconds north; Longitude - 111 degrees, 6 minutes, 29 seconds west.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 16 to 40 inches.
Depth to argillic horizon - 12 to 26 inches.
Reaction - neutral to slightly alkaline.
Average annual soil temperature - 37 to 42 degrees F.
Particle-size control section:
Clay content - 35 to 50 percent.
Rock fragment content range - 0 to 10 percent.
A horizons:
Value - 3 or 4 dry, 2 or 3 moist
Chroma - 1 or 2 moist
AB horizon:
Hue - 7.5YR or 5YR
Value - 4 or 5 dry
Chroma - 2 or 3 dry or moist
Bt1 horizon:
Hue - 7.5YR or 5YR
Value 4 or 5 dry
Texture - silty clay loam or silty clay
Bt2 and Bt3 horizons:
Chroma - 3 or 4 dry or moist
Texture - silty clay loam or silty clay
COMPETING SERIES: These are the Burnette, Cochetopa, Faim, Friana, Fulcher, Grouseville (T), Guero (T), Luna, Mancos (T), Mayflower, Paulson, Perinos (T), Richens, Runlett (T), Skutum, Slights (T), Sudpeak, Teedown (T), and Toponce series. Burnette, Faim, Grouseville, Teedown and Toponce soils have colors yellower than 7.5YR. Cochetopa, Fulcher, and Paulson soils have accumulations of calcium carbonate within the profile. Friana and Luna soils are formed in volcanics and have a lower bulk density than Bischoff soils. Guero soils contain BCt horizons, receive 24 to 28 inches of precipitation, half of which fall during summer, and have an over story of aspen. Mancos, Mayflower, Richens, Runlett, and Skutum soils are less than 60 inches deep. Perinos soils have clay or clay loam argillic horizons. Slights soils are formed in mud flow deposits and contain a high percentage of stones and boulders in the profile. Sudpeak soils have a seasonal high water table.
GEOGRAPHIC SETTING: Bischoff soils are on hills and mountains at elevations of 6,300 to 7,500 feet. They formed in loess and silty alluvium. Slopes are 15 to 50 percent. The average annual precipitation ranges from 16 to 20 inches. The average annual air temperature is 36 to 41 degrees F. The frost free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hagenbarth, Halfcircle (T), and Woodcanyon (T) soils. Hagenbarth soils have a fine-loamy particle-size control section. They are on convex slopes adjacent to Bischoff soils. Halfcircle soils are deep to a paralithic contact and are calcareous in the control section. Halfcircle soils are on north facing mountains. Woodcanyon soils are moderately deep and are on south facing, smooth to convex slopes.
DRAINAGE AND PERMEABILITY: Well drained; high to very high runoff; slow permeability.
USE AND VEGETATION: Bischoff soils are used for rangeland. The potential natural vegetation is Mountain big sagebrush and Bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Southeastern Idaho. This series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bear Lake County, Idaho 2008.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 29 inches (A1, A2, AB, and Bt1 horizons)
Argillic horizon - the zone from 16 to 61 inches (Bt1, Bt2, and Bt3 horizons)
Particle-size control section - the zone between 16 and 36 inches (Bt1 and part of the Bt2 horizon)