LOCATION UMIL                    NV

Established Series
Rev: RAF/GJS/JBF
07/2016

UMIL SERIES

The Umil series consists of well drained soils that are shallow to an indurated duripan. These soils formed in mixed alluvium from igneous rocks and some sedimentary tuff. Umil soils are on eroded fan remnants. Slopes are 2 to 50 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Xeric Haplodurids

TYPICAL PEDON: Umil gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 10 percent gravel.

A--0 to 8 cm; light brownish gray (10YR 6/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate thick and very thick platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine vesicular pores; 20 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (6 to 10 cm thick)

Bw--8 to 15 cm; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak fine and very fine angular and subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and few fine interstitial pores; 10 percent gravel; slightly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary.

Bk--15 to 28 cm; light gray (10YR 7/2) gravelly loam, brown (10YR 4/3) moist; moderate very fine angular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium roots; many very fine and few fine interstitial pores; 30 percent gravel sized pan fragments; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (Combined thickness of the Bw and Bk horizons is 18 to 25 cm)

Bqkm1--28 to 86 cm; white (10YR 8/1) indurated duripan, light yellowish brown (10YR 6/4), brownish yellow (10YR 6/6) and brownish yellow (10YR6/8) silica coated pores and bridges between sand grains, massive; extremely hard, extremely firm; few fine and very fine roots in horizontal seams and cracks only; many very fine interstitial pores; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (50 to 80 cm thick)

Bqkm2--86 to 152 cm; light gray (10YR 7/2) weakly cemented very gravelly very fine sand, massive; hard, firm, nonsticky and nonplastic; many very fine and fine interstitial pores; many thin very pale brown (10YR 7/3), continuous, indurated lamellae alternating with weakly cemented layers throughout the duripan; strongly effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Eureka County, Nevada; 2 miles north of Eureka; approximately 1600 feet east of the northwest corner of section 12, T. 19 N., R. 53 E.; USGS Eureka 7.5 minute topographic quadrangle; latitude 39 degrees 32 minutes 20 seconds N and longitude 115 degrees 57 minutes 25 seconds W; WGS84 Decimal Degrees 39.5388889 latitude, -115.9569444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 6 to 8 degrees C.
Depth to duripan: 24 to 35 cm.
Reaction: slightly alkaline through strongly alkaline, increasing with depth.

Particle-size control section - Clay content: Averages 18 to 25 percent.
Rock fragments: Averages 10 to 30 percent gravel.

A horizon - Value: 3 or 4 moist.
Chroma: 2 or 3 dry and moist.
Structure: Weak or moderate platy or granular structure.
Consistence: Soft or slightly hard when dry

Bw and Bq horizons - Value: 6 or 7 dry, 3 or 4 moist.
Chroma: 2 through 4 dry and moist.
Texture: Loam or clay loam.
Rock fragments: 10 to 35 percent.
Structure: Weak or moderate subangular or angular blocky or massive.
Consistence: Slightly hard or hard when dry

Bqkm horizons - Value: 7 or 8 dry, 6 or 7 moist.
Chroma: 1 through 4 dry and moist.
Structure: Strong medium or thick platy or it is massive.
Consistence: Extremely hard and extremely firm.

COMPETING SERIES: These are the Nouque, Raz, and Weigle series. Nouque soils have a noncalcareous Bw horizon and lack rock fragments. Raz soils have bedrock within 50 to 100 cm. Weigle soils have bedrock at a depth of 38 to 50 cm underlying the duripan.

GEOGRAPHIC SETTING: Umil soils are on summits and backslopes of eroded fan remnants. These soils formed in mixed alluvium from igneous rocks with some sedimentary tuff. Slopes are 2 to 50 percent. Elevations are 1,800 to 2,012 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, mean annual temperature is 5 to 7 degrees C, and the frost-free season is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bartine, Overland, Ratto, Rubyhill, and Siri soils. Bartine, Overland, and Siri soils lack a duripan. Overland and Siri soils are greater than 50 cm deep to bedrock. Ratto soils average 35 to 45 percent clay in the control section. Rubyhill soils have a strongly cemented duripan at 50 to 76 cm.

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

USE AND VEGETATION: Livestock grazing and wildlife habitat. The present vegetation is mainly black sagebrush, winterfat, green ephedra, bluebunch wheatgrass, Indian ricegrass, muttongrass, and needleandthread. This pedon is correlated to ecological site R028BY006NV, Shallow Calcareous Loam 10-14 P.Z.

DISTRIBUTION AND EXTENT: East-central Nevada and west-central Utah. These soils are moderately extensive. MLRA 28B.

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

SERIES ESTABLISHED: Eureka County (Diamond Valley Area), Nevada, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 18 cm. (A, Bw and part of the Bk horizons)
Indurated duripan - The zone from 28 to 86 cm (Bqkm1 horizon).
Particle-size control section - The zone from the soil surface to 28 cm (A, Bw, and Bk horizons).

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National Cooperative Soil Survey
U.S.A.