LOCATION CROPPER NV

Established Series
Rev. PWB-JVC-MJD-JBF
02/2017

CROPPER SERIES

The Cropper series consists of shallow, well drained soils that formed in residuum and colluvium derived from andesite, welded tuff, and rhyolite. Cropper soils are on mountains and hills. Slopes are 8 to 75 percent. The mean annual precipitation is about 350 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Lithic Argixerolls

TYPICAL PEDON: Cropper very cobbly loam,--forestland. The soil surface is partially covered with 20 percent gravel, 15 percent cobbles, and 5 percent stones.

A--0 to 10 cm; dark grayish brown (10YR 4/2) very cobbly loam, very dark brown (10YR 2/2) moist; moderate very fine and fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine through medium roots; common very fine tubular and interstitial pores; 20 percent gravel, 15 percent cobbles, and 5 percent stones; neutral (pH 7.2); abrupt smooth boundary. (5 to 13 cm thick)

Bt1--10 to 18 cm; dark grayish brown (10YR 4/2) extremely gravelly sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine and fine tubular pores; few faint clay films on faces of peds; 50 percent gravel and 10 percent cobbles; neutral (pH 7.2); clear smooth boundary. (0 to 12 cm thick)

Bt2--18 to 41 cm; dark yellowish brown (10YR 4/4) extremely gravelly sandy clay loam, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine and fine tubular pores; many distinct clay films on faces of peds; 60 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); abrupt wavy boundary. (18 to 25 cm thick)

R--41 cm; hard andesite.

TYPE LOCATION: White Pine County, Nevada; about 0.75 miles east of Quaky Spring; about 200 feet south and 1,000 feet west of the northeast corner of section 36, T. 13 N. R. 63 E.; USGS White Rock Creek 7.5 minute topographic quadrangle; latitude 38 degrees 57 minutes 6 seconds N and longitude 114 degrees 50 minutes 25 seconds W; WGS84 Decimal Degrees 38.9511111 latitude, -114.8472222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 25 cm, includes the Bt1 horizon.
Depth to bedrock: 36 to 50 cm to a lithic contact.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: Averages 27 to 35 percent.
Rock fragments: Averages 60 to 75 percent, mainly gravel.

A horizon
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Organic matter content: 1 to 4 percent.

Bt horizons
Hue: 10YR or 7.5YR.
Value: 3 through 5 dry, 2 through 4 moist.
Chroma: 2 through 4 moist, chroma of 4 is typically in the Bt2 horizon.
Structure: Moderate or strong, very fine to medium subangular blocky or angular blocky.
Texture: Sandy clay loam or clay loam.
Organic matter content: 1 or 2 percent.
Consistence: Soft to hard, dry; very friable to firm, moist; slightly sticky or moderately sticky, slightly plastic or moderately plastic, wet.
Other features: In some pedons thin subhorizons overlying the bedrock have textures of sandy clay with 35 to 50 percent clay.
Clay films: Few through many, faint or distinct.

COMPETING SERIES: These are the Anaud, Cleavage, Cleavmor, Gaciba, Granquin, Grosschat, Horsetrack, Mascamp, Pernty, Shalper, Slatter, and Tractuff series.

Anaud soils have 15 to 30 percent volcanic glass in the 0.02 mm to 2.0 mm fraction. Cleavage soils upper part of argillic is not mollic. Cleavmor and Mascamp soils have mollic epipedons deeper than 36 cm. Gaciba, Grosschat, Slatter and Tractuff soils have less than 27 percent clay in the particle-size control section. Granquin soils have mollic epipedons that are 25 to 36 cm thick. Horsetrack and Shalper soils are less than 36 cm deep. Pernty soils have less than 50 percent rock fragments.

GEOGRAPHIC SETTING: Cropper soils are on mountains and hills. These soils formed in residuum and colluvium derived from andesite, welded tuff, and rhyolite. Slopes are 8 to 75 percent. Elevations range from 1,890 to 2,810 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 360 mm. The mean annual temperature is 5 to 7 degrees C. The frost-free period is 80 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pioche and Segura soils. Pioche and Segura soils are clayey-skeletal and loamy respectively, very shallow and shallow to lithic contacts, and have mollic epipedons and argillic horizons.

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

USE AND VEGETATION: Cropper soils are used for wood production and wildlife habitat. The present vegetation is mainly a forest canopy of singleleaf pinyon and curlleaf mountain mahogany with an understory of mountain big sagebrush, Indian ricegrass, and pine bluegrass.

DISTRIBUTION AND EXTENT: Central Nevada. These soils are extensive with about 103,000 acres of the series mapped to date. MLRAs 28A, 28B and 29.

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

SERIES ESTABLISHED: White Pine County (Western Part), Nevada, 1990.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 18 cm (A and Bt1 horizons).
Argillic horizon - The zone from 10 to 41 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 41 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from 10 to 41 cm (Bt1 and Bt2 horizons).

Classification was updated to 11th edition on 07/2011 changed Lithic Argixerolls to Aridic Lithic Argixerolls.

National Cooperative Soil Survey
U.S.A.