LOCATION KOBEH                   NV

Established Series
Rev: WMA/RAF/GJS/JBF
02/2019

KOBEH SERIES

The Kobeh series consists of very deep, somewhat excessively drained soils that formed in alluvium derived from mixed rocks with a component of volcanic ash. Kobeh soils are on inset fans, fan skirts and stream terraces. Slopes are 0 to 8 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Durinodic Xeric Haplocambids

TYPICAL PEDON: Kobeh sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 10 percent less than 1.2 cm gravel; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 20 cm thick)

A2--5 to 18 cm; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few fine and many very fine roots; many very fine interstitial and tubular pores; neutral (pH 6.8); clear smooth boundary. (0 to 20 cm thick)

Bw--18 to 43 cm; pale brown (10YR 6/3) gravelly fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; few medium, fine and many very fine roots; many very fine tubular and interstitial pores; 20 percent less than 1.2 cm gravel; neutral (pH 7.0); clear smooth boundary. (15 to 50 cm thick)

Bq--43 to 61 cm; pale brown (10YR 6/3) gravelly light sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 30 percent hard durinodes; 30 percent 1.2 to 2.5 cm gravel; strongly alkaline (pH 8.6); clear wavy boundary. (15 to 50 cm thick)

2Bk--61 to 101 cm; light gray (10YR 7/2) very gravelly sand, light brownish gray (10YR 6/2) moist; single grained; loose, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; 50 percent gravel most of which is less than 1.2 cm; strongly effervescent; strongly alkaline (pH 8.8); abrupt broken boundary. (25 to 70 cm thick)

2C--101 to 152 cm; light gray (10YR 7/2) extremely gravelly sand, light brownish gray (10YR 6/2) moist; single grained; loose, nonsticky and nonplastic; 60 percent gravel less than 1.2 cm; strongly alkaline (pH 8.8).

TYPE LOCATION: Eureka County, Nevada; approximately 20 miles north of Eureka in Diamond Valley; about 1,400 feet south and 2,350 feet east of the northwest corner of section 8, T. 22 N., R. 53 E.; USGS Tule Dam Spring 7.5 minute topographic quadrangle; latitude 39 degrees 48 minutes 18 seconds N and longitude 116 degrees 1 minutes 32 seconds W; WGS84 Decimal Degrees 39.8050000 latitude, -116.0255556 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: 7 to 8 degrees C.
Thickness of the A and Bw horizons: 30 to 76 cm.
Depth to 2Bk horizon: 50 to 90 cm.

Particle-size control section - Clay content: Upper part is 5 to 15 percent, lower part is less than 10 percent.
Rock fragments: Average 35 to 60 percent, mainly gravel.

A horizon
Value: 5 or 6 dry, 3 or 4 moist (greater than 5.5 dry and 3.5 moist when the upper 18 cm are mixed).
Structure: Weak or moderate very thin to medium platy, subangular blocky, single grained or massive.
Reaction: Slightly acid or neutral.

Bw horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 or 3.
Texture: Gravelly sandy loam or gravelly fine sandy loam.
Structure: Weak coarse or very coarse prismatic medium or coarse subangular blocky or it is massive.
Reaction: Neutral through strongly alkaline.

Bq horizon
Hue: 10YR, 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Gravelly sandy loam or gravelly fine sandy loam.
Reaction: Neutral through strongly alkaline.
Silica cementation: 20 to 70 percent 1 to 2.5 cm hard or very hard durinodes; few to many silica bridges. Discontinuous weak or strong cementation that is 15 to 90 cm horizontally and up to 8 cm thick occurs at the lower boundary.

2Bk horizon
Hue: 10YR, 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Dominantly very gravelly sand with subhorizons of very gravelly sandy loam common in some pedons.
Reaction: Neutral through strongly alkaline.

2C or 3Bk horizons (when present)
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 6 moist.
Chroma: 1 through 3.
Texture: Some pedons have strata of gravelly fine sandy loam or very gravelly fine sandy loam below 127 cm.

COMPETING SERIES: There are no other series in this family at the present time.

GEOGRAPHIC SETTING: Kobeh soils are on inset fans, fan skirts, and stream terraces. These soils formed in alluvium derived from mixed rocks with a component of volcanic ash. Slopes are 0 to 8 percent. Elevations are 1,770 to 2,260 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 5 to 7 degrees C, and the frost-free season is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alhambra, Lone, Nayped and Silverado soils. Alhambra soils lack cambic horizons. Lone soils have indurated duripans. Nayped soils have fine-loamy particle-size control sections. Silverado soils are coarse-loamy and have continuous weakly silica-cemented subhorizons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; slow runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Mainly Kobeh soils are cultivated to alfalfa hay, pasture, and small grains. When not cultivated they are used for livestock grazing and wildlife habitat. The native plants are Wyoming big sagebrush with some bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: North-central Nevada. 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 soil surface to 18 cm (A1 and A2 horizons).
Cambic horizon - The zone from 18 to 43 cm (Bw horizon).
Duric horizon - The zone from 43 to 51 cm (Bq horizon).
Particle-size control section - The zone from 25 to 100 cm (Bq, 2Bk and part of the Bw horizons).

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National Cooperative Soil Survey
U.S.A.