LOCATION COBATUS                 NV

Established Series
Rev. WRK/WED
04/2015

COBATUS SERIES

The Cobatus series consists of very deep, somewhat poorly drained soils on lake plains adjacent to playas. They formed in mixed alluvium over lacustrine or playa sediments. Slopes are 0 to 4 percent. The mean annual precipitation is about 6 inches; the mean annual temperature is about 62 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, thermic Aeric Halaquepts

TYPICAL PEDON: Cobatus loam, rangeland. (Colors are for dry soil unless otherwise noted.)

Anz--0 to 2 inches; light gray (10YR 7/2) loam, yellowish brown (10YR 5/4) moist; massive; hard, firm, nonsticky and slightly plastic; violently effervescent, very strongly alkaline (pH 9.2); abrupt smooth boundary. (1 to 2 inches thick)

Cn1--2 to 14 inches; very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, nonsticky and slightly plastic; common fine and medium roots; common very fine and fine interstitial pores; violently effervescent; very strongly alkaline (pH 9.2) abrupt smooth boundary. (10 to 14 inches thick)

2Cn2--14 to 60 inches; very pale brown (10YR 8/3) clay loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, sticky and plastic; common fine and medium roots; common very fine and fine interstitial pores; violently effervescent; very strongly alkaline (pH 9.2)

TYPE LOCATION: Nye County, Nevada; approximately 20 miles northwest of Beatty and about 3,000 feet south and 3,000 feet east of the northwest corner of section 17, T. 9 S., R. 45 S.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry. Moist for short periods of time in the late winter and saturated within a depth of 40 inches for short periods during spring unless drained.

Soil temperature - 63 to 67 degrees F.

Control section - Percent clay: Averages 20 to 30 percent.



A horizon - Value: 7 or 8 dry, 5 or 6 moist.

Chroma: 2 or 3 dry, 2 through 6 moist.

Other features: In some pedons there is a high accumulation of surface salts which forms a structureless crust on the surface of some pedons.



C horizon - Value: 7 or 8 dry, 5 or 6 moist.

Chroma: 2 or 3 dry, 4 or 5 moist.

Texture: Dominantly loam, silt loam or clay loam, with some pedons containing thin strata or lenses of coarser or finer textures.

Consistence: Slightly sticky or sticky, slightly plastic or plastic.

Sodium absorption ratio: 20 to 50 in upper part, decreasing with depth.

Other features: Strata of coarser textures are presents below 40 inches in some pedons,

COMPETING SERIES: There are no competing series. Glann series are similar. The Glann soil has a dark A horizon and lack sodium absorption ratio values of more than 15 that diminish near the water table.

GEOGRAPHIC SETTING: Cobatus soils are on lake plains adjacent to playas. These soils formed in thin mixed alluvium or aeolian material over lake bed or playa sediments. Slopes are 0 to 4 percent. Elevations are 2,500 to 4,500 feet. The climate is arid. The winters are cool and the summers hot and dry. The mean annual precipitation is between 4 and 8 inches with relatively even distribution of precipitation with slight peaks in January and August. The mean annual temperature is about 58 to 62 degrees F. The frost-free season is about 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bluepoint soils, which have a sandy control section.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Slow runoff; moderately slow permeability.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly black greasewood, inland saltgrass, alkali sacaton, and shadscale.

DISTRIBUTION AND EXTENT: Southern Nevada. These soils are not extensive. MLRA 30.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES PROPOSED: Nye County Nevada, (Southwest Part), 1983. The name is coined from Sarcobatus Flat.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Particle-size control section - The zone from 10 to 40 inches.

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 11/2001. ET

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National Cooperative Soil Survey
U.S.A.