LOCATION VIPONT IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Pachic Argixerolls
TYPICAL PEDON: Vipont very stony loam--on a 46 percent south-facing slope at about 6,000 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted).
A--0 to 4 inches; dark grayish brown (10YR 4/2) very stony loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, few medium, and few coarse roots; many fine interstitial pores; 15 percent stones, 5 percent cobbles, and 15 percent pebbles; neutral (pH 6.8); abrupt smooth boundary. (3 to 8 inches thick)
AB--4 to 8 inches; dark grayish brown (10YR 4/2) stony loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, few medium, and few coarse roots; common medium and many fine tubular pores; 15 percent stones, 5 percent cobbles, and 10 percent pebbles; neutral (pH 7.0); clear smooth boundary. (0 to 6 inches thick)
Bt1--8 to 13 inches; very dark grayish brown (10YR 3/2) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine and common medium roots; common medium and many fine tubular pores; many distinct clay films on faces of peds and lining pores; 25 percent cobbles, 5 percent stones, and 5 percent pebbles; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 11 inches thick)
Bt2--13 to 22 inches; dark grayish brown (10YR 4/2) extremely cobbly clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; few fine and few medium roots; few fine tubular pores; many distinct and faint clay films on faces of peds and lining pores; 50 percent cobbles, 10 percent stones, and 10 percent pebbles; slightly alkaline (pH 7.4); gradual wavy boundary. (4 to 18 inches thick)
R--22 inches; hard bedrock; slightly fractured and weathered in the upper 2 to 5 inches.
TYPE LOCATION: Cassia County, Idaho; about 8 miles west of Elba and north of Fairchild Creek; near the northwest corner of the northeast 1/4, of the southeast 1/4 of section 35, T. 13 S., R. 23 E.; USGS Mount Harrison 7.5 minute topographic quadrangle; approximately 42 degrees 14 minutes 56 seconds north latitude and 113 degrees 43 minutes 48 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Moist in winter and spring, dry in summer and fall; Xeric moisture regime that borders on aridic.
Mean annual soil temperature - 41 to 47 degrees F.
Mollic epipedon thickness - 20 to 30 inches; includes the Bt1 horizon and also the Bt2 horizon in most pedons.
Depth to base of argillic horizon - 20 to 40 inches.
Depth to bedrock - 20 to 40 inches to a lithic contact.
Particle-size control section - Clay content: 24 to 35 percent; Rock fragments: 35 to 75 percent, mainly cobbles. Lithology of fragments are sandstone or quartzite.
A horizon - Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Rock fragments: 20 to 55 percent.
Reaction: Slightly acid or neutral.
Organic matter content: 2 to 6 percent.
AB horizon - Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Texture: Stony loam, cobbly clay loam, or very cobbly clay loam.
Clay content: 24 to 34 percent.
Rock fragments: 20 to 55 percent.
Reaction: Slightly acid or neutral.
Organic matter content: 1 to 6 percent.
Bt1 and Bt2 horizons - Hue: 7.5YR through 2.5Y.
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very cobbly clay loam, very cobbly sandy clay loam, extremely cobbly clay loam, or extremely cobbly sandy clay loam.
Clay content: 24 to 35 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 to 3 percent in the Bt1 horizon, 0.5 to 3 percent in the Bt2 horizon.
COMPETING SERIES: These are the Bullump, Bullvaro, Burchflat (T), Camelback, Chrisflat (T), Demner (T), Dogbed (T), Dooh (T), Erig, Krenka, Leroman (T), Lockgate (T), Murain (T), Nutval (T), Snyderville, Softback, Softscrabble, Staberg, and Vetagrande (T) series.
Bullump and Camelback soils have lithic contacts between 40 and 80 inches from the soil surface. Bullvaro, Demner, Dooh, Nutval, and Vetagrande soils have an aridic moisture regime. Burchflat soils have rock fragments of andesite, tuff, or tuff-breccia. Chrisflat, Dogbed, Krenka, Murain, Snyderville, Softback, and Softscrabble soils are very deep. Erig soils are deep to lithic contacts. Leroman and Staberg soils are moderately deep to paralithic contacts. Lockgate soils are deep to paralithic contacts.
GEOGRAPHIC SETTING: Vipont soils are on hills, mountains, and cuestas. They typically occur on backslope or scarp face positions. These soils formed in alluvium, colluvium, and residuum derived from sandstone, quartzite, and mica schist. Slopes are 4 to 60 percent. Elevation ranges from 5,000 to 7,000 feet. The mean annual precipitation is 14 to 22 inches, the mean annual temperature is 39 to 45 degrees F., and the frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acord, Chen, Mackey, and Winu soils. Acord soils are clayey-skeletal, very deep, and are on fan remnants. Chen soils are clayey-skeletal, shallow to lithic contacts, and are on adjacent slope positions. Mackey soils do not have argillic horizons and are on adjacent slope positions. Winu soils have cryic temperature regime and are on adjacent slope positions.
DRAINAGE AND PERMEABILITY: Well drained; very high surface runoff; moderately slow permeability.
USE AND VEGETATION: Vipont soils are used mainly for rangeland and wildlife habitat. The natural vegetation is mainly mountain big sagebrush, bluebunch wheatgrass, and Idaho fescue.
DISTRIBUTION AND EXTENT: Southern Idaho. These soils are moderately extensive. MLRAs 11, 13, and 25.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Cassia County (West Part), Idaho, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 22 inches (A, AB, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 8 to 22 inches (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 22 inches to underlying hard bedrock (R layer).
Particle size control section - The zone from 8 to 22 inches (Bt1 and Bt2 horizons).