LOCATION BITTERRIDGE             NV

Established Series
Rev: LJL/TM/ET
04/2015

BITTERRIDGE SERIES

The Bitterridge series consists of shallow, well drained soils that formed in colluvium and residuum from sandstone and limestone. Bitterridge soils are on low hills. Slope ranges from 4 to 15 percent. The mean annual precipitation is about 5 inches and the mean annual air temperature is about 66 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic, shallow Typic Haplocalcids

TYPICAL PEDON: Bitterridge extremely flaggy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 25 percent pebbles, 40 percent flagstones and 2 percent stones.

A--0 to 2 inches; light brown (7.5YR 6/4) extremely flaggy loam, brown (7.5YR 4/4) moist; moderate medium and thick platy structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine and fine vesicular and few fine interstitial and tubular pores; electrical conductivity 0.4 dS/m; 25 percent pebbles and 40 percent flagstones; violently effervescent (35 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.4); clear smooth boundary. (1 to 3 inches thick)

Bk1--2 to 8 inches; brown (7.5YR 5/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and few medium roots; few very fine and fine tubular pores; electrical conductivity 0.59 dS/m; 20 percent medium and coarse soft masses of calcium carbonate in matrix; 30 percent pebbles and 5 percent cobbles; violently effervescent (35 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.4); clear wavy boundary.

Bk2--8 to 12 inches; brown (7.5YR 5/4) very gravelly loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine interstitial and few fine tubular pores; electrical conductivity 0.62 dS/m; 30 percent medium and coarse soft masses of calcium carbonate in matrix; many thin calcium carbonate coats on undersides of rock fragments; 30 percent pebbles and 10 percent cobbles; violently effervescent (40 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.4); abrupt wavy boundary. (Combined thickness of the Bk horizons is 7 to 17 inches thick)

Cr--12 to 16 inches; fractured and weathered sandstone. (3 to 6 inches thick)

R--16 inches; hard sandstone bedrock.

TYPE LOCATION: Clark County, Nevada; about 26 miles south of Moapa, Nevada; approximately 5 miles west of Bitter Spring in Bitter Spring Valley; 1000 feet north and 2350 feet east of the southwest corner of section 15, T. 19 S., R. 66 E.; USGS Bitter Spring, NV 7.5 minute topographic quadrangle; 36 degrees, 17 minutes, 37.43 seconds north latitude and 114 degrees, 36 minutes, 23.98 seconds west longitude; UTM 11, 0714923e 4019186n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture - usually dry, moist in some part for short periods during winter and early spring. The ratio of summer to winter actual evapotranspiration is about 0.8, typical of the Mojave Desert transitional to Sonoran Desert. The soils have a typic aridic moisture regime.

Soil temperature: 66 to 71 degrees F.

Depth to calcic horizon: 1 to 3 inches.

Depth to paralithic contact: 10 to 20 inches.

Depth to hard bedrock: 14 to 25 inches.

Organic matter: 0 to 0.5 percent.

Control section - Rock fragments: average 35 to 60 percent, mainly from limestone and sandstone.
Clay content: 18 to 25 percent.
Calcium carbonate equivalent: 40 to 60 percent in the less than 20 millimeter fraction.

A horizon - Value: 5 or 6 dry.
Calcium carbonate equivalent of the fine earth: 20 to 40 percent.

Bk horizons - Value: 5 or 6 dry.
Chroma: 4 or 6.
Texture of the fine earth: Sandy loam or loam.
Rock fragments: 35 to 60 percent, mainly limestone and sandstone gravel.
Structure: subangular blocky or massive.
Consistence: slightly hard or hard, and very friable or friable.
Calcium carbonate equivalent of the fine earth: 20 to 45 percent.
Other features: 10 to 30 percent soft masses of secondary calcium carbonate.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Bitterridge soils are on low hills. Slope ranges from 4 to 15 percent. These soils formed in colluvium and residuum from sandstone and limestone. Elevations are 2,000 to 2,800 feet. The climate is typical of the Mojave Desert transitional to Sonoran Desert with hot, dry summers and cool, moist winters. The mean annual precipitation is 4 to 6 inches; mean annual air temperature is 64 to 69 degrees F., and the frost-free period is 240 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Helkitchen and St. Thomas soils. Helkitchen and St. Thomas soils have lithic contacts.

DRAINAGE AND PERMEABILITY: Well drained; very high runoff; moderate permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly shadscale and white bursage.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada, U.S.A.; MLRA 30. These soils are not extensive.

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

SERIES ESTABLISHED: Clark County Area, Nevada, 2006. Proposed in Clark County, Nevada, Soil Survey, 2000. The name is coined from Bitter Ridge located two miles to the northwest.

REMARKS: Diagnostic horizons and features recognized in the profile are:
Ochric epipedon - 0 to 2 inches (A horizon).
Calcic horizon - 2 to 12 inches (Bk1 and Bk2 horizons).
Paralithic contact -- 12 inches (Cr horizon).
Particle-size control section - 0 to 12 inches (A, Bk1 and Bk2 horizons).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 7/2006. ET

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National Cooperative Soil Survey
U.S.A.