LOCATION WALTI                   NV

Established Series
Rev. WED/RAF/JVC/JBF
05/2016

WALTI SERIES

The Walti series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from volcanic rocks. Walti soils are on hills, mountains, and plateaus. Slopes are 4 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Aridic Argixerolls

TYPICAL PEDON: Walti gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 25 percent stones.

A--0 to 13 cm; brown (10YR 4/3) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine interstitial pores; 25 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.4); clear smooth boundary. (10 to 25 cm thick)

2Bt1--13 to 23 cm; dark brown (10YR 3/3) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and very fine angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common medium, fine, and very fine roots; common fine tubular and few fine interstitial pores; common distinct pressure cutans on faces of peds; 5 percent gravel; slightly alkaline (pH 7.6); abrupt smooth boundary. (10 to 18 cm thick)

3Bt2--23 to 43 cm; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; strong medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine and very fine roots along faces of peds; common fine and very fine tubular pores; common prominent pressure cutans on faces of peds and few faint clay films lining pores; 5 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (15 to 36 cm thick)

3Bt3--43 to 56 cm; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 3/4) moist; strong medium and fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots along faces of peds; few fine tubular pores; many prominent pressure faces on peds and few faint clay films lining pores; 15 percent gravel and 5 percent cobbles; slightly alkaline (pH 7.8); abrupt wavy boundary. (10 to 20 cm thick)

3R--56 cm; hard rhyolite.

TYPE LOCATION: Eureka County, Nevada; about 35 miles south of Crescent Valley in the Tonkin summit area west of Roberts Mountain; approximately 1,500 feet east and 2,000 feet south of the northwest corner of section 4, T. 23 1/2 N., R. 49 E.; USGS Tonkin Summit 7.5 minute topographic quadrangle; latitude 39 degrees 54 minutes 21 seconds N and longitude 116 degrees 28 minutes 09 seconds W; WGS84 Decimal Degrees 39.9058333 latitude, -116.4691667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry from late June to mid-October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 43 cm; commonly includes the upper part of the argillic horizon.
Depth to bedrock: 50 to 76 cm to a lithic contact.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: 40 to 50 percent.
Rock fragments: 5 to 25 percent, mainly gravel. Lithology of fragments are volcanic rocks such as rhyolite, andesite, dacite, and tuff.

A horizon
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.

Bt horizons
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 3 or 4 moist. Some pedons are 6 dry in the lower subhorizon above the bedrock.
Chroma: 2 through 4, dry or moist.
Texture: Clay loam or gravelly clay loam with 27 to 35 percent clay and an abrupt lower boundary in the upper subhorizon. Clay or gravelly clay with 50 to 60 percent clay in the lower subhorizons.
Rock fragments: 5 to 25 percent, mostly gravel and cobbles.
Structure: Prismatic or angular blocky; upper subhorizons are subangular blocky in some pedons.
Consistence: Very friable to firm; moderately sticky or very sticky, moderately plastic or very plastic.

COMPETING SERIES: These are the Alyan and Prunie series.

Alyan soils do not have clay loam texture in the upper part of the argillic horizon with abrupt boundaries between the Bt1 and Bt2 horizons. Prunie soils are deep to paralithic contacts.

GEOGRAPHIC SETTING: Walti soils are on hills, mountains, and plateaus. They formed in residuum and colluvium derived dominantly from volcanic rocks. Slopes are 4 to 50 percent. Elevations range from 1,768 to 2,590 meters. The climate is semiarid with cool, 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 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cleavage, Robson, and Softscrabble soils. Cleavage soils are loamy-skeletal, shallow to lithic contacts, and have mollic epipedons and argillic horizons. Robson soils are clayey-skeletal, shallow to lithic contacts, and have argillic horizons. Softscrabble soils are loamy-skeletal, very deep, and have argillic horizons and thick mollic epipedons.

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

USE AND VEGETATION: Walti soils are used for rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, low rabbitbrush, Idaho fescue, Sandberg's bluegrass, and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Central and western Nevada. These soils are moderately extensive. MLRAs 24, 28B, and 27.

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

SERIES ESTABLISHED: Eureka County, Nevada, 1983.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 43 cm (A, 2Bt1, and 3Bt2 horizons).
Argillic horizon - The zone from 13 to 56 cm (2Bt1, 3Bt2, and 3Bt3 horizons).
Lithic contact - The boundary at 56 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from 13 to 56 cm (2Bt1, 3Bt2, and 3Bt3 horizons).

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National Cooperative Soil Survey
U.S.A.