LOCATION BROSE IDEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, frigid Lithic Ultic Argixerolls
TYPICAL PEDON: Brose extremely cobbly loam--on a northwest-facing slope of 3 percent under native rangeland at 6,550 feet elevation. (Colors are for dry soil unless otherwise stated.) When described on October 3, 1977 the soil profile was dry throughout.
A1--0 to 1 inch; brown (10YR 5/3) extremely cobbly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine to fine roots; many very fine tubular pores; 30 percent gravel, 30 percent cobbles, 5 percent stones; neutral (pH 6.8); clear smooth boundary. (0 to 4 inches thick)
A2--1 to 3 inches; brown (10YR 5/3) gravelly loam, very dark grayish brown (10YR 3/1) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 20 percent gravel; neutral (pH 6.8); clear smooth boundary. (0 to 6 inches thick)
Bt1--3 to 9 inches; brown (10YR 5/3) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common very fine and fine roots; many very fine tubular pores; common distinct clay films on faces of peds and in pores; 20 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 8 inches thick)
Bt2--9 to 11 inches; brown (10YR 5/3) gravelly clay, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine and fine roots; common very fine tubular pores; common distinct thick clay films on faces of peds and in pores; 20 percent gravel; neutral (pH 6.8) abrupt smooth boundary. (1 to 6 inches thick)
2Bt3--11 to 18 inches; reddish brown (5YR 5/3) gravelly clay, reddish brown (5YR 4/3) moist; moderate medium prismatic structure; very hard, very firm, very sticky and very plastic; common very fine and fine roots; few very fine tubular pores; many prominent clay films faces of peds and in pores; 30 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (4 to 7 inches thick)
2R--18 inches; dark gray (10YR 4/1) welded tuff bedrock black (10YR 2/1) moist; extremely hard; silica coating in places on rock faces.
TYPE LOCATION: Twin Falls County, Idaho; about 8 miles south of Rogerson, Idaho; in the northeast 1/4, northwest 1/4, northwest 1/4, section 29, T. 15 S., R. 16 E.
RANGE IN CHARACTERISTICS:
Depth to bedrock - 14 to 20 inches
Thickness of mollic epipedon - 10 to 18 inches
Average clay content in the control section - 40 to 60 percent
Solum pH - slightly acid or neutral
Average annual soil temperature - 41 to 43 degrees F.
Average summer soil temperature - 59 to 60 degrees F.
Base saturation - 60 to 70 percent in some horizons
A horizon
Value - 2 or 3 moist
Chroma - 1 through 3 dry or moist
Bt1 horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3
Clay content - 30 to 40 percent
Gravel - 15 to 30 percent
Cobbles - 0 to 5 percent
Structure Type - subangular blocky or prismatic
Bt2 and 2Bt3 horizons
Hue - 5YR through 10YR
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 through 4
Gravel - 15 to 30 percent
Cobbles - 0 to 5 percent
Clay - 50 to 70 percent
Structure Type - subangular blocky or prismatic
COMPETING SERIES: This is the Aldi (T) and Alding series. Aldi and Alding soils have an average annual soil temperature of 43 to 47 degrees F., and have precipitation greater than 16 inches.
GEOGRAPHIC SETTING: Brose soils are on summits. Slopes range from 2 to 20 percent. The soils formed from colluvium and residuum from welded tuff. Elevations are 5,800 feet to 6,600 feet. The average annual precipitation ranges from 12 to 16 inches. The average annual temperature is 40 to 44 degrees F. The frost free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Congle, Doodlelink, Eep, Forvic, Hogmalat, Keman, and Mug soils. Amboat soils occur on the same landscape and are very deep and skeletal. Congle, Doodlelink, and Eep soils occur on backslopes, footslopes and breaks. Congle and Doodlelink soils are very deep and pachic. Eep soils are ash-skeletal. Forvic and Mug soils occur on terraces and are moderately deep. Hogmalat soils occur on shoulders, backslopes and summits, are cryic, and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff; very slow permeability.
USE AND VEGETATION: Brose soils are used for rangeland. Native vegetation is Idaho fescue, bluebunch wheatgrass, and low sagebrush.
DISTRIBUTION AND EXTENT: Brose soils are of moderate extent in south central Idaho.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.
REMARKS: Base saturation: 0-1 inches - 61 percent; 1-3 inches - 70 percent; 3-9 inches - 72 percent; 9-11 inches - 77 percent; 11-18 inches - 80 percent.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 9 inches (A1, A2, and Bt1 horizons)
Argillic horizon - the zone from 3 to 18 inches (Bt1, Bt2, and 2Bt horizons)
Ultic feature - the zone from 0 to 9 inches (A1, A2, and Bt1 horizons)
Lithic contact - the contact at 18 inches (2R horizon)