LOCATION BROMAGLIN IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, frigid Calcidic Haploxerolls
TYPICAL PEDON: Bromaglin silt loam--on a 1 percent slope at 4,500 feet elevation in improved hayland. (Colors are for dry soil unless otherwise noted. When described on May 12, 1987, the soil was dry throughout.)
Ap--0 to 5 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and fine irregular pores;5 percent fine pebbles; neutral (pH 7.2); clear smooth boundary. (3 to 6 inches thick)
Bw--5 to 12 inches; brown (10YR 5/3) very fine sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, fine and medium roots; many very fine and fine irregular pores; 5 percent pebbles; neutral (pH 7.2); gradual wavy boundary. (5 to 8 inches thick)
Bk1--12 to 20 inches; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; weak fine prismatic structure parting to weak fine and medium subangular blocky; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine and fine irregular and few fine tubular pores; 10 percent pebbles; few lime coatings 1 mm thick on undersides of coarse fragments; violently effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (6 to 10 inches thick)
2Bk2--20 to 60 inches; multicolored extremely gravelly loamy coarse sand; single grain; loose; common very fine roots, common fine and medium irregular pores; 70 percent pebbles, 10 percent cobbles; few lime coatings less than 1 mm thick on undersides of some coarse fragments; strongly effervescent; slightly alkaline (pH 7.5).
TYPE LOCATION: Lemhi County, Idaho; about 0.5 miles northeast of the confluence of Ezra Creek and the Salmon River, about 1,300 feet east and 900 feet north from the southwest corner of section 4, T.17N, R.21E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 40 to 44 degrees F
Mollic epipedon thickness - 8 to 14 inches
Depth to calcic horizon - 8 to 14 inches with 15 to 20 percent calcium carbonate equivalent
Depth to contrasting material - 14 to 24 inches
Reaction - neutral of slightly alkaline
Control section - Percent clay: 4 to 10
Coarse fragments (average) - 40 to 80 percent
A horizons
Value - 4 or 5 dry
Chroma - 2 or 3 dry and moist
Bw horizon
Value - 4 or 5 dry
Chroma - 2 or 3 dry or moist
Coarse fragments - 0 to 15 percent
Bk1 horizon
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 2 to 4 dry or moist
Texture - SL, GR-SL, GR-L, VFSL
Coarse fragments - 10 to 30 percent
2Bk2 horizon
Texture - GRX-LCOS, GRX-COS
Rock fragments - 60 to 85 percent
COMPETING SERIES: These are the Bartonflat and Lesbut series. Bartonflat soils have sand and gravel at depths of 7 to 11 inches and are somewhat excessively drained. Lesbut soils lack a calcic horizon.
GEOGRAPHIC SETTING: Bromaglin soils are on stream terraces and fan terraces at elevations of 3,800 to 6,600 feet. The soils formed in alluvium. Slopes are 1 to 4 percent. The climate is cold and moist in winter and spring and dry in summer. Average annual precipitation is 11 to 13 inches. Average annual air temperature is 39 to 43 degrees F. The frost-free period is 75 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bartonflat and the Bock, Bursteadt, and Dawtonia soils. Bartonflat soils are on stream terraces and fan terraces. Bock and Bursteadt soils are on terraces and alluvial fans and have coarse-loamy particle-size control sections. Dawtonia soils are on fan terraces and mountains, lack mollic epipedons and have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained. Slow runoff. Moderate permeability in the upper part and very rapid in the lower part.
USE AND VEGETATION: Bromaglin soils are used for irrigated crops and rangeland. The natural vegetation is Wyoming big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: East-central Idaho. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lemhi County, Idaho, 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 12 inches (A and Bw horizons).
Calcic horizon - The zone from 12 to 20 inches (Bk1 horizon).
Particle-size control section - The zone from 10 to 40 inches (part of the Bw, the Bk1 and part of the 2Bk2 horizons).