LOCATION BRUSHTOP                ID

Established Series
Rev. BJD/FRK/RJS
12/2022

BRUSHTOP SERIES

The Brushtop series consists of deep, well drained soils formed in alluvium over weakly consolidated ash, tuffaceous sandstone or siltstone. These soils are on north-facing aspects on backslopes and footslopes of hills. Permeability is moderately slow. Slopes range from 20 to 40 percent. Average annual precipitation is about 18 inches and the average annual air temperature is about 39 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Argicryolls

TYPICAL PEDON: Brushtop loam, rangeland; on a 38 percent northwest-facing slope at an elevation of 6,680 feet. (Colors are for dry soil unless otherwise stated.)

A--0 to 6 inches; very dark grayish brown (10YR 3/2) loam, black (10YR 2/1) moist; moderate medium granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine and common medium and coarse roots; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (4 to 6 inches thick)

AB--6 to 12 inches; very dark grayish brown (10YR 3/2) loam, black (10YR 2/1) moist; moderate medium subangular blocky structure parting to moderate medium granular; soft, friable, slightly sticky and slightly plastic; many very fine and fine and common medium and coarse roots; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (4 to 8 inches thick)

Bt1--12 to 19 inches; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; common continuous distinct clay films on faces of peds and in pores; 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (6 to 9 inches thick)

Bt2--19 to 26 inches; dark grayish brown (10YR 4/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; strong medium prismatic structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine and few medium and coarse roots; common continuous distinct clay films on faces of peds and in pores; 15 percent gravel; neutral (pH 7.0); clear wavy boundary. (7 to 12 inches thick)

Bt3--26 to 43 inches; brown (10YR 5/3) gravelly clay loam, brown (10YR 4/3) moist; strong medium prismatic structure; hard, firm, moderately sticky and moderately plastic; few very fine, fine, and medium roots; many continuous distinct clay films on faces of peds and in pores; 15 percent gravel and 10 percent paragravel; neutral (pH 7.0); abrupt wavy boundary. (9 to 20 inches thick)

2Cr--43 to 53 inches; light gray (2.5Y 7/1) weakly consolidated ash.

TYPE LOCATION: Bear Lake County, Idaho; about 3 miles west of Bennington, Idaho; about 1,220 feet north and 2,428 feet west of the southeast corner of section 2, T. 12 S., R. 43 E. (42 degrees 24 minutes 15.9 seconds north Latitude and 111 degrees 23 minutes 42.4 seconds west Longitude.)

RANGE IN CHARACTERISTICS:

Soil moisture control section usually moist, dry in all parts for 45 consecutive days or more in the four months following the summer solstice. Xeric moisture regime.
Thickness of mollic epipedon 16 to 26 inches
Depth to paralithic contact 40 to 60 inches
Average annual soil temperature 39 to 42 degrees F. Cryic soil temperature regime
Average summer soil temperature 54 to 59 degrees

Particle-size control section
Clay content 25 to 35 percent (weighted average)
Rock fragments 0 to 20 percent

A horizon
Chroma 2 dry and 1 or 2 moist
Texture loam
Clay content 18 to 21 percent
Rock fragments 0 to 10 percent gravel
Reaction neutral (pH 6.6 to 7.3)

AB horizon
Chroma 2 dry and 1 or 2 moist
Texture loam
Clay content 18 to 24 percent
Rock fragments 0 to 10 percent gravel
Reaction neutral (pH 6.6 to 7.3)

Bt1 and Bt2 horizons
Chroma 2 dry and 1 or 2 moist
Texture loam, clay loam, gravelly clay loam
Clay content 25 to 33 percent
Rock fragments 0 to 20 percent gravel
Reaction neutral (pH 6.6 to 7.3)

Bt3 horizon
Value 4 or 5 dry and 3 or 4 moist
Chroma 2 or 3 dry or moist
Texture clay loam, gravelly clay loam
Clay content 30 to 38 percent
Rock fragments 5 to 20 percent gravel
Pararock fragments 0 to 10 percent paragravel (consists of fragments of weakly consolidated ash)
Reaction neutral (pH 6.6 to 7.3)

COMPETING SERIES: These are the Bachus, Bavdark, Benteen, Clayburn, Croydon, Crystalbutte, Davtone, Decross, Dehana, Demast, Dranburn, Dranyon, Dry Canyon, Echemoor, Hagenbarth, Hoopgobel, Millerlake, Pontuge, Senchert, Southmount, Poodle, Stubbs, Thulepah, Vadnais, and Winu series. Bachus, Benteen, Echemor, Hoopgobel, Senchert, Poodle, Stubbs, Vadnais, and Winu soils are less than 40 inches deep to a lithic or paralithic contact. Bavdark, Clayburn, Crystalbutte, Davtone, Decross, Dehana, Demast, Dranburn, Dry Canyon, Hagenbarth, Millerlake, Pontuge, Southmouth, and Thulepah soils are very deep. Croydon and Dranyon soils have a lithic contact at a depth of 40 to 60 inches.

GEOGRAPHIC SETTING:
Landform: backslopes and footslopes of hills on north-facing aspects
Elevation: 5,850 to 7,700 feet
Slope: 20 to 40 percent
Parent Material: alluvium over weakly consolidated ash, or tuffaceous sandstone or siltstone of the Salt Lake Formation.
Climate: long, cool winters; dry, warm summers
Average annual precipitation: 15 to 22 inches
Average annual temperature: 37 to 43 degrees F.
Frost-free season: 50 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cadero (T), Redpine (T), and Whitetop (T) series. Cadero soils are moderately deep to weakly consolidated ash on shoulders and summits. Redpine soils have a warmer soil temperature regime, are moderately deep, and are on backslopes and shoulders. Whitetop soils are shallow to weakly consolidated ash, have a warmer soil temperature regime, and are on shoulders and summits.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: These soils are used mainly for wildlife habitat and rangeland. The dominant native vegetation is serviceberry, mountain big sagebrush, mountain snowberry, antelope bitterbrush, Idaho fescue, lupine, basin wildrye, and bluegrass.

DISTRIBUTION AND EXTENT: Southeastern Idaho. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Bear Lake County, Idaho, 2008.

REMARKS: Depths to diagnostic horizons and features start from the mineral soil surface. Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: the zone from 0 to 26 inches (A, AB, Bt1, and Bt2 horizons)

Argillic horizon: the zone from 12 to 43 inches (Bt1, Bt2, and Bt3 horizons)

Paralithic contact - 43 inches

Particle-size control section the zone from 12 to 32 inches (Bt1, Bt2 and part of the Bt3 horizon)

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National Cooperative Soil Survey
U.S.A.