LOCATION TROUGHS                 ID+NV

Established Series
Rev. DBJ/ALH/CLM/JBF
12/2019

TROUGHS SERIES

The Troughs series consists of shallow to a duripan, well drained soils that formed in residuum, alluvium and loess derived from extrusive igneous rocks and volcanic ash. The Troughs soils are on calderas, structural benches, and plateaus. Slopes are 0 to 25 percent. The average annual precipitation is about 230 mm and the average annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Xeric Argidurids

TYPICAL PEDON: Troughs stony loam -- on a slightly convex slope of 5 percent, in native rangeland at 1,560 mm elevation. (When described on August 16, 1979, the soil was dry throughout. Colors are for air dry soil unless otherwise stated.)

A--0 to 5 cm; very pale brown (10YR 7/3) stony loam, grayish brown (10YR 5/2) moist; moderate medium platy structure parting to weak fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; many very fine and fine vesicular pores; 5 percent gravel, 10 percent cobbles, and 10 percent stones; slightly alkaline (pH 7.8); clear smooth boundary. (2 to 20 cm thick)

Bt--5 to 20 cm; pale brown (10YR 6/3) cobbly clay loam, brown (10YR 5/3) moist; moderate very fine and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine, few medium roots; common very fine tubular pores; few faint clay films on faces of peds; 10 percent gravel and 20 percent cobbles; moderately alkaline (pH 8.1); clear smooth boundary. (10 to 28 cm thick)

Bkq--20 to 38 cm; very pale brown (10YR 7/3) extremely cobbly loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; few very fine tubular pores; 65 percent indurated dominantly cobble-size duripan fragments; strongly effervescent; strongly alkaline (pH 8.9); gradual smooth boundary. (0 to 23 cm thick)

Bkqm--38 to 76 cm; very pale brown (10YR 8/2) indurated duripan, very pale brown (10YR 7/3) moist; massive or strong medium and thick platy structure; extremely hard, brittle; opalized laminations are 1/8 to 2 cm thick; 20 percent angular cobbles and stones; violently effervescent; very strongly alkaline (pH 9.3); abrupt wavy boundary. (5 to 51 cm thick)

2R--76 cm; basalt.

TYPE LOCATION: Owyhee County, Idaho; about 2 miles north of Grasmere; 800 feet south and 150 feet east of the northwest corner of section 9, T. 12 S., R. 5 E.; USGS Grasmere 7.5 minute topographic quadrangle; latitude 42 degrees 24 minutes 09 seconds north and 115 degrees 53 minutes 02 seconds W; WGS84 Decimal Degrees 42.4025000 latitude, -115.8838889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and early spring; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to calcium carbonates: 15 to 36 cm.
Depth to duripan: 30 to 50 cm.
Depth to bedrock: 50 to 100 cm.

Particle-size control section - 27 to 35 percent clay.
Rock fragments: Averages 35 to 70 percent.

A horizon
Value: 4 through 7 dry, 3 through 5 moist.
Chroma: 2 or 3.
Rock fragments: 15 to 45 percent.
Reaction: Slightly alkaline or moderately alkaline.

Bt horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 3 or 4.
Texture: Cobbly clay loam, very cobbly clay loam and very gravelly clay loam.
Rock fragments: 25 to 50 percent.
Reaction: Slightly alkaline through strongly alkaline.
Effervescence: Noneffervescent through strongly effervescent in the lower part.

Bkq horizon
Hue: 7.5YR or 10YR.
Value: 7 or 8 dry, 4 or 5 moist.
Chroma: 3 or 4.
Rock fragments: 50 to 90 percent.
Reaction: Moderately alkaline through very strongly alkaline.
Calcium carbonate equivalent: 15 to 40 percent.
Other features: Rock fragments in the lower B horizon consist of cobbles and stones with thick silica and calcium carbonate pendants and indurated duripan fragments.

COMPETING SERIES: These are the Brock, Cleet, Deepeek, Hotcreek, Indicove, Lapon, Littleailie, Malmesa, Oleman, Shinnpeak, Vinini and Wanapum series.

Brock, Cleet, Deepeek, Indicove, Littleailie, Oleman, Shinnpeak, and Wanapum soils lack bedrock within a depth of 100 cm. Hotcreek soils are less than 25 cm deep to a duripan. Malmesa soils are less than 50 cm deep to bedrock. Lapon soils have average annual soil temperature of 11 to 13 degrees C. Vinini soils are moist for 10 to 20 days cumulative between July and October due to convection storms.

GEOGRAPHIC SETTING: Troughs soils are on calderas, structural benches, and plateaus at elevations of 1,070 to 1,680 meters. Slopes range from 0 to 25 percent. These soils have formed in alluvium and loess derived from extrusive rocks and volcanic ash. The climate is cool and moist in the winter and hot and dry in the summer. Average annual precipitation ranges from 200 to 300 mm, and average annual temperature is 7 to 10 degrees C. The frost-free period is 90 to 125 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bruncan, Hotcreek, Jenor, Laped, Owsel, and Snowmore soils. Bruncan, Jenor, Laped, Owsel, and Snowmore soils have less than 35 percent rock fragments in the control section. Hotcreek soils have a duripan above a depth of 30 cm. These soils are on landscape positions similar to Troughs soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Troughs soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is Wyoming big sagebrush, Sandberg bluegrass, bottlebrush squirreltail, Thurber needlegrass, and black sagebrush.

DISTRIBUTION AND EXTENT: Southwestern Idaho. Troughs soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Elmore County Area, Idaho, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon _ The zone from the soil surface to 5 cm (A horizon).
Argillic horizon - The zone from 5 to 20 cm (Bt horizon)
Calcic horizon - The zone from 20 to 38 cm (Bkq horizon)
Indurated duripan - The zone from 38 to 76 cm (Bkqm horizon)
Lithic contact - The boundary at 76 cm (2R layer).
Particle-size control section - The zone from 5 to 30 cm (Bt horizon).

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National Cooperative Soil Survey
U.S.A.