LOCATION GRASSYCAN               NV

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

GRASSYCAN SERIES

The Grassycan series consists of very shallow and shallow to a duripan, well drained soils that formed in residuum derived from volcanic rocks. Grassycan soils are on plateaus. Slopes are 0 to 15 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Abruptic Xeric Argidurids

TYPICAL PEDON: Grassycan very gravelly fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 4 percent stones, 10 percent cobbles and 45 percent gravel.

A1--0 to 3 cm; grayish brown (10YR 5/2) very gravelly fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial pores; 5 percent stones, 5 percent cobbles, and 40 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 8 cm thick)

A2--3 to 10 cm; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; 15 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (0 to 8 cm thick)

Bt1--10 to 18 cm; pinkish gray (7.5YR 6/2) clay loam, brown (7.5YR 4/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; many distinct clay films on faces of peds; 10 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (8 to 13 cm thick)

Bt2--18 to 30 cm; brown (7.5YR 5/4) clay, brown (7.5YR 4/4) moist; moderate fine prismatic structure parting to strong fine angular blocky; hard, firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; common distinct clay films on faces of peds; 10 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (8 to 13 cm thick)

Bqm--30 to 33 cm; cemented material; extremely hard, extremely firm; continuous 1.2 to 2.5 cm thick platy material indurated by opaline silica; abrupt wavy boundary. (0.15 to 3.0 cm thick)

R--33 cm; hard, unweathered basalt.

TYPE LOCATION: Washoe County, Nevada; about 3 miles southeast of Stevens Camp and 2.5 miles east of Grassy Canyon; approximately 1,500 feet south and 2,600 feet east of the northwest corner of section 21, T. 41 N., R. 22 E.; USGS Nellie Spring Mountain 7.5 minute topographic quadrangle; latitude 41 degrees 27 minutes 12 seconds N and longitude 119 degrees 30 minutes 28 seconds W; WGS84 Decimal Degrees 41.4528210 latitude, -119.5086680 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry mid-June through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 10 degrees C.
Depth to very thin duripan: 18 to 36 cm.
Depth to bedrock: 18 to 36 cm to a lithic contact.
Other features: An abrupt horizon boundary is present between the A and Bt1 horizons accompanied by an increase in clay content of 15 or more percent.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: Averages 5 to 10 percent, mainly gravel. Lithology of fragments is volcanic rocks such as basalt or andesite.

A horizons
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 8 to 18 percent.
Reaction: Slightly acid through slightly alkaline.

Bt horizons
Hue: 5YR through 10YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Clay or clay loam.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 15 percent gravel, 0 to 5 percent cobbles.
Structure: Subangular blocky or angular blocky in the upper part, prismatic parting to angular blocky in the lower part.

Bqm horizon
Other features: Some pedons have minor amounts of identifiable secondary carbonates.

COMPETING SERIES: These are the Antholop, Esmod, Fulstone, Kunaton, Puls, Ridenbaugh, and Rogerson series.

Antholop, Esmod, Fulstone, Ridenbaugh, and Rogerson soils do not have bedrock within 150 cm of the soil surface. Kunaton soils have lithic contacts at depths of 50 to 100 cm from the soil surface and have secondary carbonates in the lower part of the argillic horizon. Puls soils have 10 to 109 cm thick duripans over lithic contacts.

GEOGRAPHIC SETTING: Grassycan soils are on plateaus. They typically occur on summit positions. These soils formed mainly in residuum derived from volcanic rocks. Slopes are 0 to 15 percent. Elevations range from 1,5700 to 1,950 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, the mean annual temperature is 7 to 8 degrees C, and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buffaran soil and the competing Fulstone soil. Buffaran soils do not have bedrock within 150 cm of the soil surface.

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

USE AND VEGETATION: Grassycan soils are used for rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, Sandberg's bluegrass, Thurber's needlegrass, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Northwestern Nevada. 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:
Ochric epipedon - The zone from the soil surface to 10 cm (A1 and A2 horizons).
Argillic horizon - The zone from 10 to 30 cm (Bt1 and Bt2 horizons).
Abruptic subgroup feature - The abrupt clay increase of more than 15 percent at 10 cm (between A2 and Bt1 horizons).
Duripan - The zone from 30 to 33 cm (Bqm horizon).
Lithic contact - The boundary at 33 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from the soil surface to 30 cm (A1, A2, Bt1, and Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.