LOCATION UDAHO                   ID

Established Series
Rev. DH/CLM
12/2019

UDAHO SERIES

The Udaho series consists of soils that are well drained and moderately deep to welded ash, that formed in colluvium and residuum from welded tuff and consolidated volcanic ash. They are on hillslopes and breaks. Slopes range from 10 to 65 percent. The average annual precipitation is about 300 mm, and average annual temperature is about 8.3 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, mesic Vitrixerandic Haplocalcids

TYPICAL PEDON: Udaho very gravelly loam - on a southeast facing slope of 28 percent under sagebrush and bunchgrass at 1,740 meters elevation. (Colors are for dry soil unless otherwise noted.) When described on June 1978, the soil profile was slightly moist to 46 cm and dry below.

A--0 to 18 cm; pale brown (10YR 6/3) very gravelly ashy loam, dark brown (10YR 4/3) moist; weak fine granular structure; slightly hard, friable, nonsticky and nonplastic; many very fine, fine and medium, common coarse roots; many very fine and fine tubular pores; 35 percent gravel; slightly effervescent; slightly alkaline (pH 7.6); gradual wavy boundary. (10 to 25 cm thick)

Bk1--18 to 36 cm; very pale brown (10YR 7/3) very gravelly ashy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic ; many very fine, fine and medium, common coarse roots; many fine tubular pores; 50 percent gravel, mostly duripan fragments; strongly effervescent (16 percent calcium carbonate); moderately alkaline (pH 8.4); clear wavy boundary. (18 to 50 cm thick)

Bk2--36 to 79 cm; very pale brown (10YR 7/3) very gravelly ashy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few coarse roots; many fine tubular pores; 45 percent gravel size duripan and tuff fragments; strongly effervescent (19 percent calcium carbonate); moderately alkaline (pH 8.4); clear wavy boundary. (23 to 46 cm thick)

Cr--79 to 152 cm; very pale brown (10YR 8/3) partially weathered volcanic ash, pale yellow (2.5Y 7/4) moist; massive; extremely hard, extremely firm; few coarse roots; slightly effervescent.

TYPE LOCATION: Twin Falls County, Idaho, about 15 miles south of Rogerson, about 800 feet south and 350 feet east of the northeast corner section 32, T. 16 S., R. 16 E.; USGS East of Jackpot 7.5 minute topographic quadrangle; latitude 41 degrees 59 minutes 45 seconds N and longitude 114 degrees 35 minutes 44 seconds W; WGS84 Decimal Degrees 41.9958333 latitude, -114.5955556 longitude.

RANGE IN CHARACTERISTICS:

Depth to secondary lime - 15 to 38 cm.
Thickness of solum - 28 to 75 cm.
Depth to partially consolidated ash (paralithic) - 50 to 100 cm.
Clay content in control section - 10 to 20 percent.
Average annual soil temperature - 8.9 to 10.0 degrees C.
Soil moisture: Usually dry, moist in the winter and spring, dry from late June through October; aridic soil moisture regime bordering on xeric.

A horizon
Value - 5 or 6 dry, 3 through 5 moist
Chroma - 2 or 3
Structure, shape - granular or platy
pH - mildly alkaline or moderately alkaline

Bk horizon
Value - 5 through 8 dry, 3 through 6 moist
Chroma - 2 through 4
Texture - GRV-SL, GRV-L
Gravel - 35 to 50 percent
Cobbles - 0 to 10 percent
Structure, shape - subangular blocky, massive
Calcium carbonate percent - 15 to 30
pH - moderately alkaline or strongly alkaline

Cr horizon
Hue - 2.5Y or 10YR
Value - 7 or 8 dry, 5 through 7 moist
Chroma - 1 through 4
Effervescence - slight to strong

COMPETING SERIES: These are the Darkbull, Hiko Peak, Nekiver, Sitar, and Waycup series. Darkbull, Hiko Peak, and Sitar soils are deep. Nekiver soils are moderately deep to lithic material. Waycup soils have an extremely stony loam Bw horizon, and are deep to basalt bedrock.

GEOGRAPHIC SETTING: Udaho soils occur on hillslopes and breaks. The slope ranges from 10 to 65 percent. The soils formed in colluvium from welded tuff and residuum from welded ash. Elevations range from 1,525 to 1,830 meters. The average annual precipitation ranges from 250 to 330 mm. The average annual temperature is 7.2 to 8.9 degrees C. The frost free season is 100 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ackett, Arbidge, Chuska, Lankbush, and Weash soils. Ackett and Chuska soils occur on terraces, and are shallow to a hardpan. Arbidge soils occur on terraces, and are moderately deep to a hardpan. Lankbush soils occur on stream terraces, are very deep, and well drained. Weash soils occur below Udaho soils on the landscape with slopes of 2 to 12 percent, have a fine loamy control section, and are shallow to ash.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, medium or rapid runoff; moderately rapid saturated hydraulic conductivity.

USE AND VEGETATION: Udaho soils are used for rangeland. Native vegetation is bluebunch wheatgrass, bottlebrush squirreltail, Thurber needlegrass, Indian ricegrass, arrowleaf balsamroot, Wyoming big sagebrush, antelope bitterbrush, and rabbitbrush.

DISTRIBUTION AND EXTENT: Udaho soils are of small extent in south central Idaho. MLRA 25.

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

SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 18 cm (A horizon).
Calcic horizon - The zone from 18 to 79 cm (Bk1 and Bk2
horizons).
Paralithic contact - The boundary at 79 cm (Cr horizon).
Particle-size control section - The zone from 25 to 79 cm (Part of the Bk1 and the Bk2 horizons.

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National Cooperative Soil Survey
U.S.A.