LOCATION AMBUSH                  NV

Established Series
Rev. CWL/TM/JVC/JBF
05/2016

AMBUSH SERIES

The Ambush series consists of very deep, well drained soils that formed in eolian deposits over lacustrine deposits derived from limestone and welded tuff. Ambush soils are on alluvial flats. Slopes are 0 to 2 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 13 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Petronodic Haplocalcids

TYPICAL PEDON: Ambush fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 40 percent cyanobacteria and 5 percent lichens which are evident when the surface is wet.

A--0 to 13 cm; very pale brown (10YR 7/3) fine sandy loam, yellowish brown (10YR 5/4) moist; moderate very thick platy structure; soft, very friable, nonsticky and slightly plastic; few very fine and fine roots; many very fine, common fine, and few medium vesicular pores; secondary calcium carbonate is finely disseminated; 22 percent calcium carbonate equivalent; violently effervescent; strongly alkaline (pH 8.8); abrupt smooth boundary. (8 to 13 cm thick)

Bk1--13 to 36 cm; very pale brown (10YR 7/3) very gravelly sandy loam, brownish yellow (10YR 6/6) moist; strong medium and coarse subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine, and few medium interstitial and tubular pores; secondary calcium carbonate is finely disseminated; 40 percent extremely hard, strongly cemented, medium spherical secondary calcium carbonate nodules; 30 percent calcium carbonate equivalent; violently effervescent; strongly alkaline (pH 8.8); gradual smooth boundary.

Bk2--36 to 79 cm; white (10YR 8/1) fine sandy loam, light brownish gray (10YR 6/2) moist; moderate medium prismatic structure parting to strong medium and coarse subangular blocky; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine, fine and medium irregular and tubular pores; secondary calcium carbonate is finely disseminated; 8 percent extremely hard, strongly cemented, medium spherical secondary calcium carbonate nodules; 33 percent calcium carbonate equivalent; violently effervescent; very strongly alkaline (pH 9.1); gradual smooth boundary. (Combined thickness of the Bk1 and Bk2 horizons is 25 to 76 cm).

Bk3--79 to 155 cm; white (10YR 8/1) fine sandy loam, pale brown (10YR 6/3) moist; strong coarse prismatic structure parting to strong medium and coarse subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine, fine and medium irregular pores; secondary calcium carbonate is finely disseminated, with few (2 percent) fine threads; 18 percent calcium carbonate equivalent; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Lincoln County, Nevada; about 14.5 miles north of highway 93 in Dry Lake Valley, about 0.25 miles west of Bristol Reservoir and about 20 feet south of jeep trail; approximately 800 feet north and 400 feet east of the southwest corner of section 9, T. 2 S., R. 64 E.; USGS Deadman Spring SE 7.5 minute topographic quadrangle; latitude 37 degrees 47 minutes 7 seconds N and longitude 114 degrees 49 minutes 23 seconds W; WGS84 Decimal Degrees 37.7852778 latitude, -114.8230556 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist for short periods in winter and early spring and intermittently moist in some part for 10 to 20 days cumulative from July through September due to convection storms; typic aridic soil moisture regime.
Mean annual soil temperature: 13 to 15 degrees C.
Depth to calcic horizon: 8 to 13 cm.
Calcic horizon thickness: 25 to 76 cm.

Particle-size control section - Clay content: 10 to 18 percent.
Rock fragments: Averages 2 to 10 percent medium sized, extremely hard, strongly cemented spherical secondary calcium carbonate nodules.

A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3 dry, 3 or 4 moist.
Calcium carbonate equivalent: 20 to 25 percent.
Reaction: Moderately alkaline or strongly alkaline.

Bk1 horizon
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 1 through 4 dry, 2 through 6 moist.
Texture: Fine sandy loam, loam, or sandy loam.
Clay content: 10 to 18 percent.
Rock fragments: 20 to 40 percent calcium carbonate-cemented nodules.
Structure: Moderate or strong, medium or coarse prismatic structure.
Calcium carbonate equivalent: 25 to 35 percent.
Reaction: Strongly alkaline or very strongly alkaline.

Bk2 horizon
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 1 through 4 dry, 2 through 6 moist.
Texture: Fine sandy loam, loam, or sandy loam.
Clay content: 10 to 18 percent.
Rock fragments: 5 to 20 percent calcium carbonate-cemented nodules.
Structure: Medium or coarse prismatic structure parting to moderate or strong subangular blocky.
Calcium carbonate equivalent: 25 to 35 percent.
Reaction: Strongly alkaline or very strongly alkaline.

Bk3 horizon
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 1 through 3 dry, 2 or 3 moist.
Texture: Very fine sandy loam, fine sandy loam, or sandy loam.
Clay content: 12 to 16 percent.
Rock fragments: 0 to 5 percent calcium carbonate-cemented nodules.
Structure: Medium or coarse subangular blocky, massive, or prismatic parting to subangular blocky.
Calcium carbonate equivalent: 15 to 20 percent.
Effervescence: Strongly effervescent or violently effervescent.
Reaction: Moderately alkaline or strongly alkaline.

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

GEOGRAPHIC SETTING: Ambush soils are on alluvial flats. These soils formed in eolian deposits over lacustrine deposits derived from limestone and welded tuff. Slopes are 0 to 2 percent. Elevations range from 1,387 to 1,478 meters. The mean annual precipitation is 125 to 175 mm, the mean annual temperature is 12 to 14 degrees C, and the frost-free period is 120 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Geer, Panacker, and Saltydog soils. Geer soils occur on alluvial plains and do not have calcic horizons. Panacker soils occur on alluvial flats and have 18 to 27 percent clay in the particle-size control section. Saltydog soils occur on alluvial flats and do not contain calcium carbonate-cemented nodules.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high saturated hydraulic conductivity.

USE AND VEGETATION: Ambush soils are used for livestock grazing and wildlife habitat. The potential native vegetation includes Indian ricegrass, bottlebrush squirreltail, and shadscale. This component is correlated to ecological site R029XY059NV, Shallow Silty 5-8 P.Z.

DISTRIBUTION AND EXTENT: South-central Nevada. These soils are not extensive with about 8,500 acres of the series mapped to date. MLRA 29.

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

SERIES ESTABLISHED: Lincoln County, Nevada, North Part, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of Bk1 horizons).
Calcic horizon - The zone from 13 to 79 cm (Bk1 and Bk2 horizons).
Petronodic subgroup feature - The zone from 13 to 36 cm (Bk1 horizon).
Particle-size control section - The zone from 25 to 100 cm (Bk2 horizon and parts of the Bk1 and Bk3 horizons).

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National Cooperative Soil Survey
U.S.A.