LOCATION DOLMAN IDEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Xeric Haplodurids
TYPICAL PEDON: Dolman silt loam--on a northeast-facing slope of 2 percent under rangeland vegetation at 3,475 feet elevation. (Colors are for air-dry soil unless otherwise stated.) When described on April 26, 1984, the soil profile was dry.
A--0 to 4 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; moderate medium platy structure; soft, friable; nonsticky and nonplastic; many very fine and fine roots; common very fine and fine tubular pores; neutral (pH 6.7); gradual wavy boundary. (4 to 7 inches thick)
BA--4 to 14 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common fine tubular pores; neutral (pH 7.0); gradual wavy boundary. (0 to 10 inches thick)
Bw--14 to 21 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine tubular pores; slightly effervescent (8 percent calcium carbonate); slightly alkaline (pH 7.4); clear smooth boundary. (6 to 20 inches thick)
2Bkq--21 to 27 inches; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; massive; very hard, firm, slightly sticky and slightly plastic; few very fine roots; few fine tubular pores; 10 percent durinodes; 10 percent gravel size duripan fragments; strongly effervescent (34 percent calcium carbonate); slightly alkaline (pH 7.8); abrupt smooth boundary. (6 to 20 inches thick)
2Bkqm--27 to 45 inches; fractured duripan; 1/4 to 3 inch silica lenses throughout; extremely hard, platy, rock-like material; gradual wavy boundary. (9 to 30 inches thick)
3Bk--45 to 61 inches; multi-colored stratified sand and gravel; single grain; loose, nonsticky and nonplastic; strongly effervescent (8 percent calcium carbonate); moderately alkaline (pH 7.9)
TYPE LOCATION: Twin Falls County, Idaho; about 17 miles northwest of Buhl, Idaho; in the southwest 1/4, southeast 1/4, southeast 1/4 of section 35, T. 7 S., R. 12 E.; USGS Indian Butte Quadrangle.
RANGE IN CHARACTERISTICS:
Soil temperature - 49 to 55 degrees F.
Depth to carbonates -12 to 24 inches
Depth to calcic horizon - 14 to 30 inches
Depth to duripan - 20 to 40 inches
Depth to bedrock - greater than 60 inches
Particle-size control section - clay - 12 to 18 percent
Rock fragments - 0 to 10 percent (mainly gravel)
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 47 degrees F.
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 to 4 dry or moist
Clay - 12 to 16 percent
Gravel - 0 to 10 percent
Bw horizon
Value - 2 to 4 moist
Clay - 12 to 24 percent
Gravel - 0 to 5 percent
Effervescence - none or slight
Calcium carbonate equivalent - 0 to 10 percent
Reaction - neutral or slightly alkaline
Bkq horizon
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 2 through 4 dry or moist
Texture - VFSL, L, or SIL
Clay - 8 to 16 percent
Gravel - 0 to 10 percent
Effervescence - strong or violent
Calcium carbonate equivalent - 15 to 40 percent
Reaction - neutral through strongly alkaline
COMPETING SERIES: These are the Burke, Minidoka, Nyssa and Sluka soils. Burke and Nyssa soils lack a calcic horizon. Minidoka and Sluka soils are less than 12 inches to carbonates.
GEOGRAPHIC SETTING: Dolman soils are on old dissected terraces and on plug domes (buttes), lava flow lobes, pressure ridges and tumuli on shield volcanoes. These soils formed in silty alluvium from loess and weathered volcanic ash over loamy or sandy alluvium from igneous materials. Slopes are 1 to 15 percent. Elevations are 3,000 to 4,350 feet. The average annual precipitation is 8 to 10 inches. The average annual temperature is 47 to 53 degrees F. The frost-free season is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Sluka soils and the Blacknest, Chuska, Purdam, Sluka, Tulch, and Yahoo soils. Blacknest soils do not have duripans. Chuska and Yahoo soils are shallow to a duripan. Purdam soils have fine-silty argillic horizons. All the above soils are on the same landform as Dolman. Tulch soils do not have duripans, have fine-silty control sections and are on lower terraces and along large drainageways.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Dolman soils are used mainly for rangeland and irrigated crops. Native vegetation is Wyoming big sagebrush, Thurber needlegrass, and Sandberg bluegrass. Irrigated crops are mainly wheat, barley, sugar beets, potatoes, beans, and alfalfa hay.
DISTRIBUTION AND EXTENT: Dolman soils are of small extent in south central and southwestern Idaho; MLRA 11.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to 4 inches (A horizon)
Cambic horizon - the zone from 14 to 21 inches (Bw horizon)
Calcic horizon - the zone from 21 to 45 inches (Bkq and Bkqm horizons)
Duripan - the zone from 27 to 45 inches (2Bkqm horizon)
Particle size control section - the zone from 10 to 27 inches
Soil moisture regime - aridic bordering xeric
Geographic setting - terms used throughout MLRA 11 to identify the setting of this soil are quire varied although all equate to the same landscape. These will be further investigation from an MLRA project level as to the accepted terms for use.
The term silty alluvium used in this series concept infers a localized influence on the mixed loess and weathered volcanic ash soil mantle by overland flow of running water.