LOCATION VALCREST NV

Established Series
Rev. RAF-GJS-JVC-JBF
01/2023

VALCREST SERIES

The Valcrest series consists of very deep, well drained soils that formed in alluvium derived from mixed igneous rocks with a component of loess. Valcrest soils are on fan remnants. Slopes are 2 to 8 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey over loamy, smectitic over mixed, superactive, mesic Xeric Natrargids

TYPICAL PEDON: Valcrest loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 8 cm; light brownish gray (10YR 6/2) loam, dark brown (10YR 3/3) moist; strong very thin platy structure; soft, very friable, slightly sticky and slightly plastic; common fine and very fine roots; common very fine vesicular pores; slightly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 10 cm thick)

A2--8 to 18 cm; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate very thin platy structure; slightly hard, very friable, moderately sticky and slightly plastic; many fine and very fine roots; common very fine tubular pores; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (8 to 13 cm thick)

A3--18 to 25 cm; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; weak thin and medium platy structure; slightly hard, very friable, moderately sticky and moderately plastic; few medium, many very fine and fine roots; few fine and many very fine tubular pores; 5 percent gravel; slightly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (5 to 10 cm thick)

Btnk1--25 to 46 cm; light yellowish brown (10YR 6/4) clay, brown (7.5YR 4/4) moist; strong medium prismatic structure parting to strong medium angular blocky; hard, friable, very sticky and very plastic; common fine and very fine roots; many very fine tubular pores; common faint and distinct clay films on faces of peds and lining pores; strongly effervescent; secondary carbonates segregated in common fine filaments; strongly alkaline (pH 8.8); clear wavy boundary. (18 to 23 cm thick)

Btnk2--46 to 56 cm; light yellowish brown (10YR 6/4) clay, brown (7.5YR 4/4) moist; moderate medium prismatic structure parting to moderate fine angular blocky; hard, friable, very sticky and very plastic; few fine and very fine roots; common very fine tubular pores; many distinct clay films on faces of peds and lining pores; violently effervescent; secondary carbonates segregated in many fine filaments; 5 percent gravel; strongly alkaline (pH 9.0); clear wavy boundary. (10 to 15 cm thick)

Btnk3--56 to 74 cm; very pale brown (10YR 7/3) clay loam, yellowish brown (10YR 5/4) moist; weak coarse and medium prismatic structure; hard, very friable, moderately sticky and moderately plastic; few fine and very fine roots; common very fine tubular pores; common faint clay films on faces of peds and lining pores; 10 percent gravel; violently effervescent; secondary carbonates segregated in many fine filaments; very strongly alkaline (pH 9.2); abrupt wavy boundary. (15 to 20 cm thick)

2Bk--74 to 152 cm; light gray (10YR 7/2) sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few medium, common fine and very fine roots; common very fine tubular pores; 10 percent gravel; violently effervescent; secondary carbonates segregated in few fine filaments; very strongly alkaline (pH 9.2).

TYPE LOCATION: Eureka County, Nevada; in Pine Valley about 14 miles south and 14 miles east of the community of Crescent Valley; approximately 1,600 feet north and 530 feet east of the southwest corner of section l5, T. 27 N., R. 50 E.; USGS Curlow Flat 7.5 minute topographic quadrangle; latitude 40 degrees 13 minutes 09 seconds N and longitude 116 degrees 19 minutes 44 seconds W; WGS84 Decimal Degrees 40.2191667 latitude, -116.3288889 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 11 degrees C.
Depth to base of natric horizon: 60 to 90 cm.
Depth to strongly contrasting materials: 60 to 90 cm.

Particle-size control section - Clay content: 35 to 50 percent in the upper part and 12 to 20 percent in the contrasting lower part.
Rock fragments: 0 to 15 percent in the upper part and 5 to 15 percent in the contrasting lower part. Lithology of fragments is mixed igneous rocks such as andesite, rhyolite, and granite.

A horizons
Value: 3 or 4 moist.
Chroma: 2 or 3, dry or moist.

Btnk horizons
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay loam or clay.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 15 percent gravel.
Salinity (EC): 2 to 4 mmhos/cm.
Sodicity (SAR): 13 to 45.
Reaction: Strongly alkaline or very strongly alkaline (up to pH 9.6).
Calcium carbonate equivalent: 3 to 5 percent.

2Bk horizon
Texture: Sandy loam or gravelly sandy loam.
Clay content: 12 to 20 percent.
Rock fragments: 5 to 15 percent gravel; some pedons may have subhorizons with up to 30 percent gravel.
Salinity (EC): 2 to 16 mmhos/cm.
Sodicity (SAR): 13 to 45.
Reaction: Very strongly alkaline (up to pH 11.0).
Calcium carbonate equivalent: 3 to 5 percent.

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

GEOGRAPHIC SETTING: Valcrest soils are on fan remnants. They typically occur on summit positions. These soils formed in alluvium derived from mixed igneous rocks with a component of loess. Slopes are 2 to 8 percent. Elevations range from 1,590 to 1,830 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, the mean annual temperature is 8 to 9 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fortank, Pineval, Tomera, and Tulase soils. Fortank soils are fine, moderately deep to paralithic contacts, and have argillic horizons. Pineval soils are loamy-skeletal, have argillic horizons, and have horizons with firm consistence and a brittle manner of failure. Tomera soils are fine and have horizons in the substratum with more than 35 percent rock fragments. Tulase soils are coarse-silty and have horizons with durinodes.

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

USE AND VEGETATION: Valcrest soils are used for rangeland and wildlife habitat. The vegetation is mainly Wyoming big sagebrush, bottlebrush squirreltail, Sandberg's bluegrass, and rabbitbrush.

DISTRIBUTION AND EXTENT: Central Nevada. These soils are not extensive with about 7,400 acres of the series mapped to date. MLRA 24.

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

SERIES ESTABLISHED: Eureka County Area, Nevada, 1983.

REMARKS: This revision of February 2004 updates the taxonomic class from Fine, smectitic, mesic Xeric Natrargids.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 25 cm (A1, A2, and A3 horizons).
Natric horizon - The zone from 25 to 74 cm (Btnk1, Btnk2, Btnk3 horizons).
Major lithologic discontinuity - The abrupt change to loamy material at 74 cm (2Bk horizon).
Identifiable secondary carbonates - The zone from 25 to 152 cm (Btnk1, Btnk2, Btnk3, and 2Bk horizons).
Particle-size control section - The zone from 25 to 74 cm (Btnk1, Btnk2, and Btnk3 horizons).

National Cooperative Soil Survey
U.S.A.