LOCATION NOPEG                   NV+CA

Established Series
Rev. JBF/TM
01/2020

NOPEG SERIES

The soils of the Nopeg series are shallow, well drained soils formed in volcanic ash and alluvium from volcanic rocks over residuum from soft tuff. Nopeg soils are on rock pediments. Slopes range from 0 to 4 percent. The mean annual precipitation is about 180 mm and the mean annual air temperature is about 7.2 C.

TAXONOMIC CLASS: Ashy, glassy, mesic, shallow Sodic Haplocambids

TYPICAL PEDON: Nopeg ashy sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partly covered with 10 percent obsidian gravel.

A1--0 to 5 cm, light gray (2.5Y 7/2) ashy sandy loam, dark grayish brown (2.5Y 4/2) moist; strong thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine to medium vesicular pores; violently effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (3 to 8 cm thick).

A2--5 to 13 cm, pale yellow (2.5Y 8/2) ashy sandy loam, grayish brown (2.5Y 5/2) moist; moderate very thick platy structure; hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine and common fine vesicular pores; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (0 to 13 cm thick).

Bw--13 to 28 cm, light gray (10YR 7/2) ashy sandy loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine tubular pores; violently effervescent; strongly alkaline (pH 9.0); clear wavy boundary. (15 to 23 cm thick).

Bkn--28 to 48 cm, pale yellow (2.5Y 8/2) ashy sandy loam, light yellowish brown (2.5Y 6/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; 10 percent paragravel; few 0.5 to 1 millimeter, soft filaments of carbonates; violently effervescent; very strongly alkaline (pH 9.2); abrupt wavy boundary. (13 to 23 cm thick).

Cr--48 to 74 cm, light gray (2.5Y 7/1) and pale yellow (2.5Y 7/3) tuff, gray (2.5Y 5/1) and light olive brown (2.5Y 5/3) moist; few thin carbonate coats in horizontal fractures; few pockets of very fine roots in horizontal fractures.

TYPE LOCATION: Washoe County, Nevada; about 360 feet south and 740 feet east of the northwest corner corner of section 9, T. 36 N., R. 19 E.; USGS Juniper Springs 7.5 minute topographic quadrangle; 41 degrees, 01 minutes, 19.7 seconds north latitude and 119 degrees, 51 minutes, 45.4 seconds west longitude; WGS84 Decimal Degrees 41.0221389 latitude, -119.8626111 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry, intermittently moist in late winter and spring. Aridic soil moisture regime.

Mean annual soil temperature - 8.3 to 10.0 C.
Depth to a paralithic contact - 36 to 50 cm.
Mineralogy - 60 to 90 percent volcanic glass in the 0.2 to 2.0 millimeter fraction.

Control section: Clay content - 12 to 18 percent.
Rock fragments - 0 to 10 percent volcanic gravel; 0 to 30 percent paragravel, usually less than 10 percent in all horizons except immediately above the tuff.

A horizon
Value: 6 through 8 dry.
Chroma: 2 or 3.
Reaction: Moderately alkaline to very strongly alkaline.
Sodicity: SAR is 5 to 13.

Bw horizons
Hue: 10YR or 2.5Y.
Value: 6 or 7, dry; 4 or 5, moist.
Chroma: 2 through 4.
Clay content: 12 to 18 percent.
Structure: Weak or moderate subangular blocky.
Reaction: Strongly alkaline or very strongly alkaline.
Sodicity: SAR is 13 to 30.

Bkn horizons
Hue: 2.5Y or 5Y.
Value: 7 or 8, dry; 5 or 6, moist.
Chroma: 2 through 4.
Texture: Ashy sandy loam.
Clay content: 12 to 18 percent.
Reaction: Very strongly alkaline.
Sodicity: SAR is 13 to 60.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Nopeg soils are on rock pediments at elevations of 1,375 to 1,525 meters. These soils formed in a very thin mantle of volcanic ash and alluvium derived from mixed volcanic rock sources over residuum from soft tuff. Slopes range from 0 to 4 percent. The climate is cool, semiarid with a mean annual precipitation of about 150 to 200 mm. Mean annual temperature ranges from 6.7 to 8.3 degrees C. The frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Pegler and Old Camp soils. Pegler soils have Bw horizons with SAR less than 13 and have an aridic bordering xeric soil moisture regime. Old Camp soils have very gravelly and cobbly clay loam Bt2 horizons and are shallow over basalt bedrock.

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

USE AND VEGETATION: These soils are used for livestock grazing. The vegetation is principally shadscale, bud sagebrush, bottlebrush squirreltail, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Washoe County, Nevada, Surprise Valley-Home Camp Area. These soils are of small extent.

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

SERIES ESTABLISHED: Surprise Valley-Home Camp Area, California and Nevada, 2000.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 18 cm (The A1, A2 and part of the Bw horizon).
Cambic horizon - The zone from 13 to 28 cm (The Bw horizon).

Paralithic contact - The boundary at 48 cm (The Cr horizon).

The particle size control section - The zone from 25 to 48 cm (Part of the Bw and the Bkn horizons).

Mineralogy - Glass content of the .2 to 2 millimeter fraction is more than 30 percent throughout.

Sodic subgroup feature - The SAR exceeds 13 in the Bw and Bkn horizons, a zone 36 cm thick.

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National Cooperative Soil Survey
U.S.A.