LOCATION SOEN IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Calcic Argixerolls
TYPICAL PEDON: Soen clay loam - on a northeast, concave slope of 12 percent at 7,150 feet. (Colors are for dry soil unless otherwise noted. When the soil was described on June 12, 1985, the soil was moist to 20 inches.)
A--0 to 2 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine subangular blocky structure parting to weak very fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine and few medium roots; many very fine and fine tubular and irregular pores; 15 percent gravel; neutral (pH 6.8); clear smooth boundary. (1 to 3 inches thick)
AB--2 to 7 inches; brown (10YR 5/3) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; common very fine and fine tubular and irregular pores; 15 percent gravel; moderately alkaline (pH 7.9); clear wavy boundary. (3 to 7 inches thick)
Bt1--7 to 12 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate fine and medium prismatic structure; slightly hard, friable, very sticky and moderately plastic; common very fine and fine, and few medium roots; common very fine and fine tubular pores; many distinct clay films lining pores and on faces of peds; neutral (pH 7.2); gradual wavy boundary.
Bt2--12 to 20 inches; pale brown (10YR 6/3) clay loam, light brownish gray (2.5Y 6/2) moist; moderate medium prismatic structure; hard, firm, very sticky and moderately plastic; common very fine and fine medium roots; many very fine and fine tubular pores; common faint and few distinct clay films lining pores and on faces of peds; neutral (pH 7.2); gradual wavy boundary. (combined thickness of the Bt horizons 8 to 20 inches)
2Btkq--20 to 36 inches; very pale brown (10YR 7/3) gravelly clay loam, light brownish gray (2.5Y 6/2) moist; strong fine and medium prismatic structure; slightly hard, firm, very sticky and very plastic; common very fine and few fine and medium roots; few very fine and fine tubular and common medium irregular pores; many distinct clay films on faces of peds; 15 percent gravel, 10 percent cobbles; lime and silica coatings, 1 to 2 mm thick, on undersides of coarse fragments; violently effervescent on face of prisms, strongly effervescent on inside of prisms; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)
2Bkq--36 to 60 inches; light gray (10YR 7/2) gravelly clay loam, light olive gray (5Y 6/2) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; common very fine dead roots; common very fine and fine tubular and common medium irregular pores; 25 percent gravel, 5 percent cobbles; lime and silica coatings, 1 to 2 mm thick, on undersides of coarse fragments; soft secondary lime in pores; violently effervescent; moderately alkaline (pH 7.9).
TYPE LOCATION: Custer County, Idaho; about 14 miles south of Challis, Idaho; approximately 1,500 feet south and 200 feet west from the northeast corner, sec. 10, T. 11 N., R. 19 E. Latitude - 44 degrees, 18 minutes, 03 seconds North; Latitude - 114 degrees, 11 minutes, 32 seconds West.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 41 to 44 degrees F.
Thickness of mollic epipedon - 7 to 19 inches and typically includes the upper part of the argillic horizon.
Depth to calcic horizon - 14 to 30 inches with 15 to 25 percent calcium carbonate.
Depth to bedrock - greater than 60 inches
Particle-size control section:
Clay content - 35 to 50 percent
A or Ap horizon
Value - 4 or 5 dry
Chroma - 2 or 3 dry or moist
Reaction - neutral or slightly alkaline
Bt horizons
Hue - 10 YR or 2.5Y
Value - 4 through 7 dry and 3 through 6 moist
Chroma - 2 to 4 dry or moist
Texture - clay, silty clay loam, clay loam, or silty clay
Reaction - neutral through moderately alkaline
2Btkq horizon
Hue - 10YR, 2.5Y or 5Y
Value - 6 or 7 dry, 4 to 6 moist
Chroma - 2 through 4 dry or moist
Texture - gravelly clay loam or cobbly clay loam
Rock fragment content - 15 to 25 percent
Reaction - slightly or moderately alkaline
2Bkq horizon (when present)
Hue - 10YR or 2.5Y
Value - 6 or 7 dry or moist
Chroma - 2 or 3 dry or moist
Rock fragment content - 15 to 30 percent
Reaction - slightly through strongly alkaline
Bk horizon (when present)
Value 6 to 8 dry, 5 or 6 moist
Chroma - 2 through 4 dry or moist
Texture - silt loam, loam, gravelly loam, silty clay loam, or sandy loam
Clay - 15 to 33 percent
Rock fragment content - 0 to 20 percent
Reaction - slightly through strongly alkaline
COMPETING SERIES: These are the Ant Flat, Durkee, Gemid, Geneva and Silverlake series. Ant Flat soils have hue of 7.5YR or redder. Durkee and Gemid soils are moderately deep to bedrock. Geneva soils are somewhat poorly drained. Silverlake soils have a duripan at 40 to 60 inches.
GEOGRAPHIC SETTING: Soen soils are on mountainsides, fan terraces and toeslopes. Elevations range from 5,300 to 7,600 feet. Slopes are 0 to 40 percent. Parent material is mixed alluvium and colluvium. Soen soils are on northeast concave slopes. The mean annual precipitation is 10 to 16 inches including snowfall, and mean annual temperature is 38 to 42 degrees F. Frost-free period is 40 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Justesen, Droem, Acord, and Dredge soils. The Dredge and Justesen soils are moderately fine textured. Acord and Droem soils are clayey-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderate runoff; slow permeability.
USE AND VEGETATION: This soil is primarily used for livestock grazing. Vegetation consists of Wyoming big sagebrush, basin big sagebrush, bluebunch wheatgrass, and needleandthread.
DISTRIBUTION AND EXTENT: Southeast Idaho; the soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer County, Idaho, 1999.
REMARKS: Diagnostic features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 12 inches (A, AB, and Bt1 horizons)
Argillic horizons - the zone from 7 to 27 inches (Bt1, Bt2, and part of the 2Btkq horizons)
Calcic horizon - the zone from 20 to 60 inches