LOCATION NOPAH                   NV

Established Series
Rev. HJB/RLB/TM
12/2015

NOPAH SERIES

The Nopah series consists of very deep, well-drained soils that formed in alluvium from mixed rock sources. The Nopah soils are on inset fans, fan skirts and alluvial flats. Slopes are 0 to 8 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 62 degrees F.

TAXONOMIC CLASS: Fine-silty, carbonatic, thermic Typic Torriorthents

TYPICAL PEDON: Nopah loam, wildlife habitat. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; moderate medium platy structure; soft, very friable, slightly sticky and slightly plastic; few fine roots; few fine vesicular and tubular pores; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (2 to 4 inches thick)

C1--2 to 6 inches; light gray (10YR 7/2) loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure parting to strong thin platy; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 5 inches thick)

C2--6 to 9 inches; light gray (10YR 7/2) silt loam, yellowish brown (10YR 5/4) moist; weak medium prismatic structure parting to strong thin platy; slightly hard, friable, sticky and plastic; common fine roots; common fine and few medium tubular pores; violently effervescent; strongly alkaline (pH 8.8); abrupt wavy boundary. (3 to 5 inches thick)

C3--9 to 18 inches; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure parting to strong coarse and thin platy; slightly hard, friable, sticky and plastic; common fine and few medium roots; few fine tubular pores; violently effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (10 to 12 inches thick)

C4--18 to 30 inches; very pale brown (10YR 7/3) silty clay loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure; slightly hard, friable, very sticky and plastic; few very fine and fine roots; few fine tubular pores; violently effervescent; very strongly alkaline (pH 9.4); clear smooth boundary. (10 to 14 inches thick)

C5--30 to 46 inches; very pale brown (10YR 7/3) silty clay loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure; slightly hard, friable, very sticky and plastic; few very fine and fine roots; few fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2); clear smooth boundary. (15 to 20 inches thick)

C6--46 to 61 inches; very pale brown (10YR 7/3) silty clay loam, yellowish brown (10YR 5/4) moist; weak coarse prismatic structure; slightly hard, friable, very sticky and plastic; few fine roots; few fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2).

TYPE LOCATION: Nye County, Nevada; approximately 50 feet south and 200 feet east of the Junction of Gamebird and Homestead roads in Pahrump Valley and about 50 feet south and 150 feet east of the northwest corner of section 6 T. 21 S., R. 54. E., 39 degrees, 9 minutes, 54 seconds north latitude and 116 degrees, 2 minutes, 27 seconds west longitude.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry; moist in some parts for short periods during winter and early spring months, Typic Aridic moisture regime.The ratio of soil moisture utalized for evapotranspiration between summer and winter is about 0.4:1, typical of the Mojave Desert.

Soil temperature - 59 to 65 degrees F.

Other features: A few weakly cemented cylindrical castings are present in the upper 40 inches of some pedons.

Effervescence - Slightly effervescent to violently effervescent.

Calcium carbonate equivalent: 40 to 65 percent.



Control section - Clay content: 20 to 35 percent.



A horizon - Value: 6 or 7 dry.

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

Reaction: Moderately alkaline to very strongly alkaline.



C horizon - Hue: Dominantly 10YR with strata of 5Y common in some pedons.

Value: 6 or 7 dry, 3 through 5 moist.

Chroma: 2 through 4 moist or dry.

Structure: Prismatic, platy or massive.

Texture: Stratified loam, silt loam, clay loam, silty clay, loam and clay.

Consistence: Soft through hard, very friable through firm, slightly sticky through very sticky, slightly plastic or plastic.

Reaction: Strongly alkaline or very strongly alkaline.

COMPETING SERIES: There are no competing series at this time. Similar soils are the Armesa, Glencarb and Karro series. Armesa and Karro soils have calcic horizons with visible masses of secondary lime ranging from soft to hard consistence and are moistened frequently by summer rainfall. Glencarb soils have organic carbon content that decreases irregularly with depth.

GEOGRAPHIC SETTING: Nopah soils are on inset fans, fan skirts and alluvial flats. These soils formed in alluvium from mixed rock sources of mostly limestone, with components of quartzite and reworked lacustrine sediments. Slopes are 0 to 8 percent. Elevations are 2400 to 3000 feet. The climate is arid with hot dry summers and cool moist winters, typical of the Mojave Desert. The mean annual precipitation is 3 to 5 inches; mean annual temperature is 60 to 65 degrees F., and frost-free season is 200 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haymont, and Rumpah soils. Haymont have a coarse-silty, particle-size control section and Rumpah soils have a fine particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained, slow runoff; slow permeability.

USE AND VEGETATION: Building sites, irrigated crops and wildlife habitat. The present vegetation is mainly cattle saltbush, shadscale and fourwing saltbush. Irrigated crops are alfalfa and small grains.

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

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

SERIES ESTABLISHED: Nye County, Nevada, Southwest Part, 1985. The name was taken from the Nopah Mountain range.

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

Ochric epipedon - The zone from 0 to 7 inches (A, C1 and part of the C2 horizons).

Particle-size control section - The zone between 10 to 40 inches (lower portion of C3 horizon and upper portion of C5 horizon.)

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 1/2001. ET

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National Cooperative Soil Survey
U.S.A.