LOCATION ASHTRE                  NV+CA

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

ASHTRE SERIES

The Ashtre series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from andesitic tuff and similar volcanic rocks. Ashtre soils are on plateaus and ash flows. Slopes are 2 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy, glassy, frigid Vitritorrandic Argixerolls

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

A1--0 to 5 cm; pale brown (10YR 6/3) very gravelly ashy loam, dark brown (10YR 3/3) moist; moderate thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine vesicular pores; 40 percent gravel and 2 percent cobbles; slightly acid (pH 6.4); clear wavy boundary. (3 to 8 cm thick)

A2--5 to 18 cm; brown (10YR 5/3) ashy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; many very fine tubular pores; 10 percent gravel and 1 percent cobbles; neutral (pH 6.6); clear wavy boundary. (10 to 23 cm thick)

Bt1--18 to 28 cm; brown (10YR 5/3) ashy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; many very fine, common fine and few medium roots; common very fine and few fine tubular pores; common faint clay films on faces of peds and lining pores; 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 28 cm thick)

Bt2--28 to 43 cm; light yellowish brown (10YR 6/4) ashy clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure; very hard, very friable, moderately sticky and moderately plastic; common very fine, few fine and medium roots; many very fine tubular pores; common faint and distinct clay films on faces of peds, lining pores and as clay bridges between sand grains; 10 percent gravel and 1 percent cobbles; neutral (pH 6.8); clear wavy boundary. (13 to 28 cm thick)

Bt3--43 to 66 cm; light brown (7.5YR 6/4) ashy clay loam, strong brown (7.5YR 4/6) moist; moderate medium and coarse subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine and common fine tubular pores; common faint and few distinct clay films on faces of peds, lining pores and as clay bridges between sand grains; 10 percent gravel and 3 percent cobbles; neutral (pH 7.0); abrupt wavy boundary. (18 to 76 cm thick)

Cr--66 cm; soft, weathered andesitic tuff; can be dug with difficulty; thin silica coats on bedrock.

TYPE LOCATION: Washoe County, Nevada; about 9 miles northeast of Vya in Little Basin; in a nonsectionized township near the projected northwest corner of section 3, T. 43 N., R. 20 E.; USGS Massacre Lake NW 7.5 minute topographic quadrangle; latitude 41 degrees 40 minutes 57 seconds N and longitude 119 degrees 43 minutes 48 seconds W; WGS84 Decimal Degrees 41.6825000 latitude, -119.7288889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist 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: 25 to 40 cm; usually includes the Bt1 horizon.
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 60 percent in coarse silt through very coarse sand fractions.
Reaction: Neutral or slightly acid.

Particle-size control section - Clay content: 27 to 35 percent.
Rock fragments: 5 to 15 percent gravel. Lithology of fragments are volcanic rocks such as tuff.

A1 horizon
Value: 5 or 6 dry, 2 or 3 moist. (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 horizon
Value: 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.

Bt1 horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 through 6, dry or moist.
Clay content: 20 to 25 percent.
Structure: Angular blocky or subangular blocky.
Consistence: Hard or very hard dry, very friable or friable moist.
Rock fragments: 5 to 15 percent, mainly gravel.
Organic matter content: 1 to 3 percent.

Bt2 and Bt3 horizons
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 through 6, dry or moist.
Clay content: 27 to 35 percent.
Structure: Angular blocky or subangular blocky.
Consistence: Hard or very hard dry, very friable or friable moist.
Rock fragments: 5 to 15 percent, mainly gravel.

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

Ashdos soils have 18 to 25 percent clay and 15 to 30 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: Ashtre soils are on plateaus and ash flows. They typically occur on north-facing shoulder and backslope positions. They formed in residuum and colluvium derived from andesitic tuff and similar volcanic rocks of pyroclastic origin. Slopes are 2 to 50 percent. Elevations range from 1,475 to 2,440 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 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 Ashcamp, Tusune, and Westbutte soils. Ashcamp soils are ashy, shallow to paralithic contacts, and have a mesic temperature regime. Tusune soils are ashy-skeletal, moderately deep to paralithic contacts, and have a cryic temperature regime. Westbutte soils are loamy-skeletal, moderately deep to lithic contacts, have thick Mollic epipedons, and do not have argillic horizons.

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

USE AND VEGETATION: Ashtre soils are used for livestock grazing and wildlife habitat. The present vegetation is dominantly mountain big sagebrush, Idaho fescue, needlegrass, and bluebunch wheatgrass.

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 28 cm (A1, A2 and Bt1 horizons).
Argillic horizon - The zone from 18 to 66 cm (Bt1, Bt2 and Bt3 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 66 cm (A1, A2, Bt1, Bt2 and Bt3 horizons).
Paralithic contact - The boundary at 66 cm to underlying soft bedrock (Cr layer).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 18 to 66 cm (Bt1, Bt2 and Bt3 horizons).

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National Cooperative Soil Survey
U.S.A.