LOCATION BARNUM WY+SD UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Ustic Torrifluvents
TYPICAL PEDON: Barnum very fine sandy loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; reddish brown (5YR 5/4) very fine sandy loam, reddish brown (5YR 4/4) moist; moderate very fine granular structure; soft, very friable; slightly effervescent, calcium carbonate disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (3 to 6 inches thick)
C--4 to 60 inches; reddish brown (2.5YR 5/5) loam stratified with thin lenses of fine sandy loam and light clay loam, reddish brown (2.5YR 4/5) moist; massive with lenses of unaltered parent sediment; slightly hard, very friable; strongly effervescent, calcium carbonate disseminated and as soft masses in some lenses; moderately alkaline (pH 8.4).
TYPE LOCATION: Johnson County, Wyoming; NW1/4, NE1/4 of sec. 6, T. 41 N., R. 83 W. 43 degrees 33 minutes 22 seconds north latitude and 106 degrees 51 minutes 34 seconds west longitude.
RANGE IN CHARACTERISTICS: These soils typically contain free carbonates throughout but may be leached a few inches in some pedons. Organic carbon ranges from .6 to 3 percent in the upper 10 inches and decreases irregularly with depth. The mean annual soil temperature is about 47 to 53 degrees F. The particle size control section is highly stratified and typically averages loam or light clay loam with 18 to 35 percent clay and more than 15 percent fine or coarser sand. Strata of sandy loam, silt loam, silty clay loam, and fine sandy loam are common. Rock fragments are variable between strata but average from 0 to 10 percent pebbles. Exchangeable sodium ranges from 4 to 15 percent throughout the soil. EC typically ranges from 2 to 8 mmhos throughout under natural conditions but may range to 16 mmhos where poorly irrigated.
The A horizon has hue of 7.5YR through 2.5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 2 through 6. Reaction is slightly through strongly alkaline.
The C horizon has hue of 5YR through 10R, value of 4 through 7 dry, 3 through 5 moist, and chroma of 2 through 6. Some strata have visual accumulations of salts and carbonates which are typically discontinuous throughout the extent of the pedon. Reaction is slightly through strongly alkaline. Some pedons may have buried horizons below 40 inches.
COMPETING SERIES: These are the Haverdad, Haverson, Haysham, Manikan, Panitchen, San Mateo, and Suwanee soils. Haverdad, Haverson, and San Mateo soils have hue of 10YR or yellower throughout. Hysham soils are very strongly alkaline and have compact subsurface horizons with hard consistence. Manikan and Suwanee soils are intermittently moist in July through September, and December through February. Panitchin soils have hues of 5Y through 7.5YR in the C horizon.
GEOGRAPHIC SETTING: Barnum soils are on flood plains and alluvial terraces. These soils formed in calcareous alluvium derived from red beds containing siltstone, shale, and sandstone. Slopes are 0 to 8 percent. Elevations are 4,000 to 6,600 feet. The mean annual precipitation is about 12 inches and ranges from 10 to 14 inches with about half falling as snow or rain in April, May, and early June. The mean annual temperature is about 43 to 49 degrees F. The frost-free season is estimated to range from 110 to 135 days depending upon elevation, aspect, and air drainage.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Neville and Redbank soils and the competing Haverdad soils. Neville soils have uniform textures and a uniform decrease in organic carbon. Redbank soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; medium and low runoff; permeability is moderate or moderately slow because of stratification.
USE AND VEGETATION: Rangeland, wildlife habitat, and irrigated farming. Native vegetation consists of basin wildrye, green needlegrass, western wheatgrass, blue grama, rubber rabbitbrush, and silver sagebrush.
DISTRIBUTION AND EXTENT: Central Wyoming, western South Dakota, and eastern Utah. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Butte County, South Dakota; 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 4 inches (A)
MLRR- G
SIRs- WY0004, WY0865