LOCATION SCHURZ NV

Established Series
Rev. JBF-JVC
05/2016

SCHURZ SERIES

The Schurz series consists of very deep, well drained soils that formed in volcanic ash and alluvium derived from mixed igneous rocks. Schurz soils are on stream terraces and flood plains. Slopes are 0 to 2 percent. The mean annual precipitation is about 125 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Ashy, glassy, nonacid, mesic Vitrandic Torrifluvents

TYPICAL PEDON: Schurz ashy fine sandy loam--irrigated cropland. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 5 cm; brown (10YR 5/3) ashy fine sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine interstitial and tubular pores; neutral (pH 7.2); abrupt smooth boundary. (3 to 10 cm thick)

A--5 to 23 cm; brown (10YR 5/3) ashy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine tubular pores; slightly alkaline (pH 7.8); clear smooth boundary. (10 to 28 cm thick)

AC--23 to 71 cm; pale brown (10YR 6/3) ashy very fine sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine tubular pores; 5 percent medium distinct brownish yellow (10YR 6/6) moist relict masses of iron accumulation; slightly alkaline (pH 7.8); clear smooth boundary. (25 to 50 cm thick)

C1--71 to 114 cm; pale brown (10YR 6/3) ashy very fine sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, slightly sticky and nonplastic; few very fine to medium roots; few fine tubular pores; 15 percent medium distinct brownish yellow (10YR 6/6) moist relict masses of iron accumulation; slightly alkaline (pH 7.8); clear smooth boundary. (25 to 64 cm thick)

2C2--114 to 152 cm; pale brown (10YR 6/3) stratified coarse sand to ashy sandy loam, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; few fine tubular pores; neutral (pH 7.2).

TYPE LOCATION: Mineral County, Nevada; on the Walker River Indian Reservation about 0.4 miles northeast of Schurz; approximately 960 feet north and 440 feet east of the southwest corner of section 25, T. 13 N., R. 28 E.; USGS Schurz 7.5 minute topographic quadrangle; 38 degrees 57 minutes 23.1 seconds north latitude and 118 degrees 48 minutes 32.4 seconds west longitude,WGS84 Decimal Degrees 38.9561111 latitude, -118.809167 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in some part of the moisture control section for short periods during winter and early spring, dry from later spring through fall unless irrigated; Typic aridic soil moisture regime.
Mean annual soil temperature: 12 to 14 degrees C.
Depth to seasonal high water table: Greater than 152 cm.
Reaction: Neutral through moderately alkaline.
Other features: Organic carbon decreases irregularly with depth due to alluvial stratification of textures; 15 to 45 percent biotite mica in the fine sand fraction by grain count.

Particle-size control section - Clay content: Averages 8 to 18 percent.

A horizons
Value: 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Volcanic glass content: 15 to 50 percent in the coarse silt through fine sand fractions.
Oxalate aluminum plus one-half oxalate iron: 0.1 to 0.4 percent.
Other features: Munsell colors are dark enough to fit mollic epipedon criteria when thickness is 25 cm or more. The epipedon fails the moisture criterion of the mollic epipedon required characteristics due to lack of adequate moisture during the growing season.

AC and C horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Ashy fine sandy loam, ashy very fine sandy loam, or ashy loam.
Clay content: 8 to 18 percent.
Structure: Subangular blocky, platy, or is massive.
Consistence: Soft to hard dry, very friable to friable, nonsticky to sticky, nonplastic to moderately plastic.
Volcanic glass content: 30 to 75 percent in the coarse silt through fine sand fractions.
Other features: Relict redox concentrations of iron or manganese may occur in any subhorizon; Some pedons have thin horizons of ashy silt loam.

2C horizon
Texture: Gravelly coarse sand to ashy silty clay loam.
Other features: Relict redox concentrations of iron or manganese may occur in any subhorizon.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Schurz soils are on stream terraces and flood plains. They formed in volcanic ash and alluvium derived from mixed igneous rocks such as granodiorite and andesite. Slopes are 0 to 2 percent. Elevations range from 1,220 to 1,280 meters. The climate is arid with cool, moist winters and hot, dry summers. The mean annual precipitation is 100 to 150 mm, the mean annual temperature is 11 to 13 degrees C, and the frost-free period is 130 to 150 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carwalker, Slawmaster, and Walkeriver soils. Carwalker and Walkeriver soils are sandy. Slawmaster soils are fine-silty and have lower content of volcanic glass.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low surface runoff; moderately high over high saturated hydraulic conductivity. These soils are susceptible to rare flooding year-round or occasional flooding for very brief periods between March and July.

USE AND VEGETATION: Schurz soils are used for irrigated cropland, rangeland, wildlife habitat, and some urban development. Alfalfa hay is the main crop. The vegetation in rangeland on stream terraces is mainly Torrey quailbush, black greasewood, and scattered mature Fremont cottonwoods. A phase on active flood plains may have a plant community that is riparian cottonwood forest.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 27.

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

SERIES ESTABLISHED: Mineral County Area, Nevada, 2005.

REMARKS: This series was on the inactive series list and was not classified using Soil Taxonomy. The name was originally used in the Report of the Physical Survey of the Walker River Indian Reservation, Schurz, Nevada published by the Soil Conservation Service in May 1940. The series is being reestablished by mapping it in the same area under a similar concept to the original series. The reestablished series is now classified to the standard of Soil Taxonomy, 12th edition, 2014.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (Ap and part of the A horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 25 to 100 cm (Part of the AC horizon and C1 horizons).

ADDITIONAL DATA: Volcanic glass and mica contents determined locally by optical grain count with a polarizing petrographic microscope.

National Cooperative Soil Survey
U.S.A.