LOCATION IZAR                    NV

Established Series
Rev. DWW-RLB-JVC-JBF
11/2016

IZAR SERIES

The Izar series consists of shallow and very shallow, well drained soils that formed in residuum and colluvium derived from dolomite, tuff, conglomerate and sandstone. Izar soils are on hills, fan remnants, and rock pediments. Slopes are 0 to 75 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, calcareous, mesic Lithic Xeric Torriorthents

TYPICAL PEDON: Izar very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The surface is partially covered by approximately 60 percent gravel.

A1--0 to 3 cm; light brownish gray (2.5Y 6/2) very gravelly loam, dark grayish brown (2.5Y 4/2) moist; moderate thin platy structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine roots; many very fine interstitial and common very fine and fine vesicular pores; 35 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (3 to 10 cm thick)

A2--3 to 13 cm; light brownish gray (2.5Y 6/2) very gravelly loam, dark grayish brown (2.5Y 4/2) moist; moderate fine granular structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine interstitial pores; 35 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (0 to 10 cm thick)

Bk1--13 to 20 cm; light brownish gray (2.5Y 6/2) very gravelly loam, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine, common fine and few medium roots; many very fine interstitial pores; common distinct secondary calcium carbonate coats on the bottom of rock fragments; 50 percent gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (5 to 23 cm thick)

Bk2--20 to 28 cm; pale yellow (2.5Y 7/4) very gravelly loam, light olive brown (2.5Y 5/4) moist; weak fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine, common fine and few medium roots; many very fine interstitial pores; common distinct secondary calcium carbonate coats on bottom of rock fragments; 50 percent gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 13 cm thick)

R--28 cm; hard fractured tuff; secondary calcium carbonate and secondary silica coats in fractures.

TYPE LOCATION: Elko County, Nevada; about 31 miles north of Wells, 6.5 miles northwest of Wilkins, and 2 miles west of U.S. Highway 93; in the northwest quarter of section 25, T. 42 N., R. 63 E.; USGS Harris Canyon 7.5 minute topographic quadrangle; latitude 41 degrees 30 minutes 09 seconds N and longitude 114 degrees 47 minutes 58 seconds W; NAD 83; WGS84 Decimal Degrees 41.5024806 latitude, -114.7994444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist late fall through early spring, dry mid-July through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to bedrock: 18 to 36 cm to a lithic contact.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 5 to 35 percent.

Particle-size control section - Clay content: 18 to 25 percent.
Rock fragments: 40 to 75 percent, mainly gravel.

A horizons
Hue: 2.5Y or 10YR.
Value: 4 through 6 moist, 6 or 7 dry.
Chroma: 2 or 3, dry or moist.
Other features: Commonly has duripan fragments covering up to 75 percent of the surface.

Bk horizons
Hue: 2.5Y or 10YR.
Value: 6 through 8 dry, 4 or 5 moist.
Chroma: 2 through 4, dry or moist.
Structure: Fine or medium subangular blocky.
Texture: Loam or sandy loam.
Modifiers: Very gravelly or extremely gravelly.
Consistence: Soft or slightly hard dry, slightly sticky or sticky and slightly plastic or plastic wet.
Identifiable secondary carbonates: None to common on the bottom of rock fragments, less than 5 percent by volume.

COMPETING SERIES: These are the Lomoine, Wala, and Wesfil series.

Lomoine soils average less than 18 percent clay in the particle-size control section and are intermittently moist for 10 to 20 days cumulative during the summer months. Wala soils average less than 18 percent clay in the particle-size control section, are intermittently moist for 10 to 20 days cumulative during the summer months, and are dominated by channers. Wesfil soils average less than 18 percent clay in the particle-size control section and have mean annual soil temperature of 12 to 14 degrees C.

GEOGRAPHIC SETTING: Izar soils are on hills, fan remnants, and rock pediments. These soils formed in residuum and colluvium derived from dolomite, tuff, conglomerate, sandstone, and related calcareous sedimentary rocks. Slopes are 0 to 75 percent. Elevations are 1,520 to 2,200 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, the mean annual temperature is 7 to 9 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chiara, Orovada, Oupico, Puett, and Shalper soils. Chiara soils are shallow to an indurated duripan. Orovada soils are very deep. Oupico soils are moderately deep to a strongly cemented duripan. Puett soils are shallow to a paralithic contact and have less than 35 percent rock fragments in the particle-size control section. Shalper soils have a mollic epipedon and an argillic horizon.

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

USE AND VEGETATION: Izar soils are used for livestock grazing and wildlife habitat. The vegetation is mainly black sagebrush, littleleaf horsebrush, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are moderately extensive. The series concept and main acreage is in MLRA 25, while other acreage occurs in MLRAs 28A and 28B.

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

SERIES ESTABLISHED: Elko County, Nevada, Northeast Part, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1, A2 and part of Bk1 horizons).
Identifiable secondary carbonates - The zone from 13 to 28 cm (Bk1 and Bk2 horizons).
Lithic contact - The boundary at 28 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from the soil surface to 28 cm (A1, A2, Bk1, and Bk2 horizons).

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National Cooperative Soil Survey
U.S.A.