LOCATION ASHDOS                  NV+CA

Established Series
Rev. SES-TM-JVC-JBF
12/2019

ASHDOS SERIES

The Ashdos series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from andesitic tuff and similar volcanic rocks. Ashdos soils are on plateaus, hills, ash flows, and mountains. Slopes are 4 to 50 percent. The mean annual precipitation is about 330 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy, glassy, frigid Vitritorrandic Argixerolls

TYPICAL PEDON: Ashdos very gravelly ashy fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; light brownish gray (10YR 6/2) very gravelly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 40 percent gravel; neutral (pH 6.8); clear wavy boundary. (3 to 8 cm thick)

A2--5 to 18 cm; brown (10YR 5/3) gravelly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine tubular pores; 20 percent gravel; neutral (pH 7.0); clear wavy boundary. (13 to 23 cm thick)

A3--18 to 30 cm; brown (10YR 5/3) gravelly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; strong fine and medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and common fine tubular pores; 20 percent gravel; neutral (pH 7.2); clear wavy boundary. (0 to 18 cm thick)

Bt1--30 to 48 cm; light yellowish brown (10YR 6/4) gravelly ashy sandy clay loam, brown (10YR 4/3) moist; strong fine and medium angular blocky structure; very hard, very friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine tubular pores; common faint and few distinct clay films on faces of peds and lining pores; 20 percent gravel; neutral (pH 7.2); gradual smooth boundary. (13 to 28 cm thick)

Bt2--48 to 61 cm; light yellowish brown (10YR 6/4) gravelly ashy sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse angular blocky structure; very hard, very friable, moderately sticky and moderately plastic; common very fine roots; common very fine tubular pores; common faint and few distinct clay films on faces of peds and lining pores; 30 percent gravel; slightly alkaline (pH 7.4); gradual smooth boundary. (23 to 76 cm thick)

Cr--61 cm; very pale brown (10YR 7/3) soft, weathered andesitic tuff; can be dug with difficulty; about 10 percent fine gravel and 30 percent medium gravel in the rock matrix; thin (<1 mm) silica coats over bedrock.

TYPE LOCATION: Washoe County, Nevada; about one mile west of Vya; approximately 1,900 feet south and 2,200 feet east of the projected northwest corner of section 5, T. 42 N., R. 19 E.; USGS Fortynine Mountain 7.5 minute topographic quadrangle; latitude 41 degrees 35 minutes 32 seconds N and longitude 119 degrees 52 minutes 49 seconds W; WGS84 Decimal Degrees 41.5923889 latitude, -119.8791667 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section in winter and spring; dry from July through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 20 to 40 cm.
Depth to base of argillic horizon: 50 to 100 cm.
Depth to bedrock: 50 to 100 cm to a paralithic contact. The paralithic materials below the contact are vitric tuffs.
Volcanic glass content: 35 to 90 percent in the very fine sand and fine sand fractions.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: 18 to 25 percent.
Rock fragments: Average 15 to 30 percent gravel. Lithology of fragments are volcanic rocks such as tuff.

A1 horizon
Value: 5 or 6 dry, 2 or 3 moist. A dry value of 6 is only in the thin A1 horizon and the upper 18 cm when mixed has a dry value of 5.
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.

A2 and A3 horizons (when present)
Value: 2 or 3 moist
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.

Bt horizons
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 18 to 25 percent.
Rock fragments: 15 to 35 percent gravel in any individual horizon; Average 15 to 30 percent gravel.
Structure: Angular blocky or subangular blocky.
Consistence: Hard or very hard dry, very friable or friable moist.

COMPETING SERIES: These are the Ashtre, Lastcall, Millenium, and Stauffer series.

Ashtre soils have 27 to 35 percent clay and 5 to 15 percent gravel in the particle-size control section. Lastcall soils are moderately deep to lithic contacts. Millenium and Stauffer soils are very deep.

GEOGRAPHIC SETTING: Ashdos soils are on plateaus, hills, ash flows, and mountains. They occur on north-facing shoulders and backslopes. They formed in residuum and colluvium derived from andesitic tuff and similar volcanic rocks of pyroclastic origin. Slopes are 4 to 50 percent. Elevations range 1,475 to 2,135 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 360 mm, the mean annual temperature is 6 to 7 degrees C. and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashone and Bearbutte soils. Ashone soils are ashy, moderately deep to paralithic contacts, and have a mesic temperature regime. Bearbutte soils are coarse-loamy, deep to paralithic contacts, and have argillic horizons and thick Mollic epipedons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium or high surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Ashdos soils are used for livestock grazing and wildlife habitat. The present vegetation is dominantly low sagebrush, Idaho fescue, Thurber's needlegrass, and antelope bitterbrush.

DISTRIBUTION AND EXTENT: Northwestern Nevada and northeastern California. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Washoe County, Nevada (North Part), 1995.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 30 cm (A1, A2, and A3 horizons).
Argillic horizon- The zone from 30 to 61 cm (Bt1 and Bt2 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 61 cm (A1, A2, A3, Bt1, and Bt2 horizons).
Paralithic contact - The boundary at 61 cm to underlying soft bedrock (Cr layer).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 30 to 61 cm (Bt1 and Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.