LOCATION SWEDE IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Argicryolls
TYPICAL PEDON: Swede silt loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine and very fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; slightly acid (pH 6.1); abrupt smooth boundary. (1 to 3 inches thick)
A2--2 to 4 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak very thin platy structure parting to moderate fine granular; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine vesicular pores; slightly acid (pH 6.1); abrupt smooth boundary. (1 to 2 inches thick)
AB--4 to 9 inches; brown (10YR 4/3) silt loam, dark brown (7.5YR 3/2) moist; weak medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine tubular pores; slightly acid (pH 6.3); clear smooth boundary. (5 to 7 inches thick)
BA--9 to 15 inches; brown (7.5YR 5/3) silty clay loam, dark brown (7.5YR 3/2) moist; weak medium prismatic structure parting to weak medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine tubular pores; slightly acid (pH 6.3); clear smooth boundary. (7 to 10 inches thick)
Bt1--15 to 30 inches; pale brown (10YR 6/3) silty clay loam, brown (7.5YR 5/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few fine roots; common very fine tubular pores; distinct nearly continuous pinkish gray (7.5YR 7/2) clay films, brown (7.5YR 4/4) moist, on faces of peds; slightly acid (pH 6.3); gradual smooth boundary. (10 to 14 inches thick)
Bt2--30 to 52 inches; very pale brown (10YR 7/3) silty clay loam, brown (7.5YR 5/4) moist moderate or strong medium or coarse prismatic structure parting to moderate medium subangular blocky; hard, firm, moderately sticky and moderately plastic; many very fine tubular pores; distinct continuous brown (7.5YR 4/4) moist, clay films on faces of peds; slightly acid (pH 6.3); gradual smooth boundary. (20 to 36 inches thick)
BCt--52 to 60 inches; very pale brown (10YR 7/3) fine gravelly silty clay loam, brown (7.5YR 5/4) moist; moderate or strong medium or coarse prismatic structure parting to moderate medium subangular blocky; hard, firm, moderately sticky and moderately plastic; many very fine tubular pores; faint nearly continuous brown (7.5YR 4/4) moist, clay films on faces of peds; slightly acid (pH 6.3); gradual smooth boundary.
TYPE LOCATION: Valley County, Idaho; about 10 miles southwest of Cascade; 1,570 feet east and 50 feet north of the southwest corner of the NW1/4 section 10, T.12N., R.4E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 41 to 45 degrees F.
Average summer temperature - 51 to 58 degrees F.
Solum thickness - 35 to over 60 inches
Most pedons - extremely gravelly material (grus) underlies the solum.
Base saturation - 60 to 85 percent
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Bt horizon
Hue - 10YR or 7.5YR
Value - 4 through 7 dry, 3 through 5 moist
Chroma - 2 through 4 dry and moist
Texture - CL, SICL
Clay - 27 to 32 percent
COMPETING SERIES: These are the Hourglass, Mult, Quietus, Sponser, and Wildcow series. Hourglass soils average 20 to 35 percent rock fragments in the control section. Mult and Quietus soils have a lithic contact at depths of 20 to 40 inches. Sponsor soils have 15 to 35 percent rock fragments in the control section. Wildcow soils formed in colluvium from shale and do not have AB or BA horizons.
GEOGRAPHIC SETTING: Swede soils are on alluvial fans and footslopes. Slopes are 1 to 60 percent. The soils formed in mixed alluvial material from basaltic and granitic sources. Elevations are 4,100 to 5,300 feet. The climate is subhumid having warm, dry summers and cold, wet winters. The average annual precipitation is 24 to 27 inches and includes 8 to 11 feet of snowfall. The average annual temperature is 39 to 43 degrees F. The frost-free season is about 60 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gestrin, Nusula, Shellrock and Donnell soils have less than 50 percent base saturation. Shellrock and Donnell soils have coarse or moderately coarse textured control sections.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Used mainly for pasture, range and some forestry. Vegetation is mainly aspen, pine grass, sagebrush, open stands of ponderosa pine, Douglas fir, bluegrass, and bromegrass.
DISTRIBUTION AND EXTENT: Distributed in the colder areas of the Idaho Batholith bordering the valley floors. The soil is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Valley Area, Idaho, 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from 0 to 15 inches (A1, A2, AB and BA horizons)
Argillic horizon - zone from 9 to 60 inches (Bt1, Bt2, and BCt horizons)
Moisture regime - udic