LOCATION HAMRUB IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Calciargidic Argixerolls
TYPICAL PEDON: Hamrub silt loam on a 2 percent east facing slope at an elevation of 4,720 feet in rangeland. When described on June 8, 1983, the soil was moist below 5 inches. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak fine platy structure parting to moderate fine granular; soft, very friable, slightly sticky and slightly plastic; many fine and medium, few coarse roots; many very fine and fine tubular pores; neutral (pH 7.0); clear smooth boundary. (1 to 5 inches thick)
A2--2 to 5 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium, few coarse roots; many very fine and fine tubular pores; neutral (pH 7.2); clear wavy boundary. (2 to 6 inches thick)
BA--5 to 10 inches; yellowish brown (10YR 5/4) silt loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium, few coarse roots; many very fine and fine tubular pores; neutral (pH 7.2); clear wavy boundary. (0 to 12 inches thick)
Bt--10 to 26 inches; yellowish brown (10YR 5/4) silty clay loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; common fine and medium, few coarse roots; common very fine and fine tubular pores; common thin clay films on faces of peds and lining pores; neutral (pH 7.2); gradual wavy boundary. (10 to 20 inches thick)
Btk--26 to 41 inches; yellowish brown (10YR 5/4) silty clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; common fine and medium roots; common very fine and fine tubular pores; few thin clay films on faces of peds and lining pores; about 5 percent pebbles; strong effervescence (20 percent calcium carbonate); mildly alkaline (pH 7.6); abrupt broken boundary. (9 to 20 inches thick)
2Bkq--41 to 43 inches; very pale brown (10YR 7/4) silt loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few fine roots matted on dislodged duripan fragments; few fine tubular pores; about 10 percent gravel sized duripan fragments; strong effervescence (20 percent calcium carbonate); mildly alkaline (pH 7.8); abrupt smooth boundary. (0 to 13 inches thick)
2Bkqm--43 to 48 inches; white (10YR 8/2) indurated duripan, massive, extremely hard, extremely firm; common fine roots matted on top of laminar capping of duripan; violent effervescence (35 percent calcium carbonate); strongly alkaline (pH 8.5); abrupt wavy boundary. (2 to 10 inches thick)
3R--48 inches; fractured rhyolite bedrock with 2Bqk material in fractures.
TYPE LOCATION: Blaine County, Idaho about 8 miles south and 5 miles west of Gannett; 2,000 feet east and 850 feet south of the northwest corner of section 13, T. 2 S., R. 18 E.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 15 inches
Depth to duripan - 40 to 50 inches
Depth to bedrock - 45 to 60 inches
Depth to secondary carbonates - 24 to 31 inches
Average annual soil temperature - 47 to 52 degrees F.
Clay content in the control section - 20 to 32 percent
A horizon
Value - 4 or 5 dry and 2 or 3 moist
Chroma - 2 or 3 dry or moist
BA horizon
Value - 4 or 5 dry and 2 or 3 moist
Chroma - 2 through 4 dry or moist
Clay content - 16 to 20 percent
Bt horizon
Hue - 10YR or 7.5YR
Value - 5 or 6 dry and 3 or 4 moist
Chroma - 3 or 4 dry or moist
Textures - SIL or SICL
Clay content - 20 to 32 percent
Reaction - neutral to mildly alkaline
Btk horizon
Value - 5 or 6 dry and 3 or 4 moist
Chroma - 3 or 4 dry or moist
Textures - SIL or SICL
Calcium carbonate equivalent - 15 to 30 percent
Rock fragment content - 0 to 5 percent
Clay content - 20 to 32 percent
Reaction - mildly to moderately alkaline
2Bkq horizon
Value - 6 or 7 dry and 5 or 6 moist
Chroma - 3 or 4 dry or moist
Textures - SIL or L
Calcium carbonate equivalent - 15 to 30 percent
Rock fragment content - 0 to 10 percent gravel size duripan fragments Clay content - 16 to 20 percent
Reaction - mildly to moderately alkaline
2Bkqm horizon
Value - 7 or 8 dry and 5 through 7 moist
Chroma - 2 or 3 dry or moist
Calcium carbonate equivalent - 25 to 40 percent
Pebble content - 0 to 5 percent
Cobble content - 0 to 5 percent
Thickness of duripan - 2 to 10 inches
Cementation of duripan - indurated
Thickness of silica caps - 2 to 10mm
Reaction of moderately to strongly alkaline
COMPETING SERIES: These are the Kimama and Marley series. Kimama soils have only few patchy clay films, have cemented nodules in the Argillic horizon, and lack a duripan or bedrock contact between 40 and 60 inches. Marley soils have fine textures in the lower part of the argillic and have buried Bt horizons.
GEOGRAPHIC SETTING: Hamrub soils are on basalt plains. Slopes range from 1 to 12 percent. Elevation ranges from 4,200 to 5,000 feet. The soils formed in loess and silty alluvium. The average annual precipitation is 11 to 13 inches, most of which falls as snow and early spring rain. The average annual air temperature is 45 to 50 degrees F. The frost free season is 85 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adios, Gooding, Bostrum, and Yutrue soils. Adios soils are moderately deep to a duripan. Burmah soils lack mollic epipedons and have more than 35 percent clay in the control section. Bostrum soils are moderately deep to bedrock. Yutrue soils have ochric epipedons and are very deep. Gooding, Bostrum, and Yutrue soils occur on the same landscape. Adios soils occur on sides of buttes.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, and moderately slow permeability.
USE AND VEGETATION: Mainly used for rangeland. Vegetation is Wyoming big sagebrush, basin big sagebrush, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Hamrub soils are inextensive in south central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizon and features recognized in this soil are:
Mollic epipedon - occurs from the soil surface to approximately 10 inches (A1, A2, and BA horizons)
Argillic horizon - is the zone from approximately 10 to 41 inches (Bt and Btk horizons)
Calcic horizon - the zone from 26 to 43 inches (Btk and Bkq horizons)