LOCATION SMOUT IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Torrifluventic Haploxerolls
TYPICAL PEDON: Smout gravelly loam -- on a 1 percent slope at 3,800 feet elevation in pasture. (Colors are for dry soil unless otherwise noted. When described on July 3, 1990, the soil was dry from 0 to 10 inches and moist from 10 to 60 inches).
A--0 to 7 inches; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine, fine and medium roots; common fine pores; 25 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 8 inches thick)
AC--7 to 12 inches; grayish brown (10YR 5/2) extremely gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many fine irregular pores; 65 percent gravel, 5 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 12 inches thick)
C1--12 to 26 inches; multicolored extremely gravelly sand; few fine prominent yellowish brown (10YR 5/6) moist redox concentrations on coarse fragments; single grain; loose; common fine roots; many fine irregular pores; 75 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary. (11 to 14 inches thick)
C2--26 to 60 inches; multicolored extremely gravelly coarse sand; few fine prominent yellowish brown (10YR 5/6) moist redox concentrations on coarse fragments; single grain; loose; many fine irregular pores; 65 percent gravel, 25 percent cobbles; slightly alkaline (pH 7.4).
TYPE LOCATION: Lemhi County, Idaho; about 7 miles north of Salmon, Idaho, about 2,000 feet west and 1,000 feet north of the southeast corner of section 6, T.22N., R.22E.
Latitude - 45 degrees, 15 minutes, 41 seconds North;
Longitude - 113 degrees, 53 minutes, 31 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 42 to 44 degrees F.
Depth to redox features - 1 to 4 feet
Depth to high water table - 4 to 6 feet (April to June)
Mollic epipedon thickness - 10 to 20 inches
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Reaction - slightly or moderately alkaline
AC horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Reaction - slightly or moderately alkaline
Texture - GRX-SL, GRX-L, GRV-FSL
Coarse fragments - 55 to 75 percent
C horizon
Reaction - slightly or moderately alkaline
Texture - GRX-S, GRX-COS, GRX-LCOS
Coarse fragments - 65 to 90 percent
COMPETING SERIES: This is the Borco series. Borco soils are calcareous throughout the loamy material above the sand and gravel layer.
GEOGRAPHIC SETTING: Smout soils are on flood plains. These soils formed in alluvium from mixed sources. Slopes are 0 to 2 percent. Elevations are 3,700 to 5,100 feet. The climate is cold and moist in winter and spring, and dry in summer. Average annual precipitation is 9 to 12 inches. Average annual temperature is 40 to 42 degrees F. The frost-free period is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ajax, Bursteadt, Cowbone, Tohobit, and Zeegee soils. Ajax soils are poorly drained and have fine-smectitic particle-size control sections. Bursteadt soils are moderately well drained, have a calcic horizon, and have coarse-loamy particle-size control sections. Cowbone soils are poorly drained, have a calcic horizon and have coarse-loamy particle-size control sections. Tohobit soils are somewhat poorly drained and have a calcic horizon. Zeegee soils are poorly drained and have fine-loamy particle-size control sections. All of these soils are on nearby landscapes.
DRAINAGE AND PERMEABILITY: Moderately well drained. Slow runoff. Permeability is moderate in the upper part and very rapid in the lower part. This soil floods occasionally for brief periods during January through June.
USE AND VEGETATION: Mostly cultivated under irrigation for hay and pasture. The principal native vegetation is streambank wheatgrass and black cottonwood.
DISTRIBUTION AND EXTENT: East-central Idaho. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lemhi County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 12 inches. (The A and AC horizons).
Particle-size control section - the zone from 10 to 40 inches (part of the AC, the C1 and part of the C2 horizons)