LOCATION LABOU                   NV

Established Series
Rev. WED/ELS/JVC
05/2016

LABOU SERIES

The Labou series consists of very shallow and shallow, well drained soils that formed in lacustrine deposits derived from mixed rocks. Labou soils are on hills. Slopes are 2 to 15 percent. The mean annual precipitation is about 127 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Natrargids

TYPICAL PEDON: Labou gravelly loamy fine sand--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 3 cm; light brownish gray (10YR 6/2) gravelly loamy fine sand, dark brown (10YR 3/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine interstitial and few very fine tubular pores; about 30 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (3 to 8 cm thick)

E--3 to 8 cm; light gray (10YR 7/2) fine sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine and few fine and medium roots; many very fine and fine vesicular pores; about 10 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (3 to 8 cm thick)

Btnk1--8 to 18 cm; brown (10YR 5/3) very gravelly clay, brown (10YR 5/3) moist; moderate medium and coarse columnar structure; very hard, friable, very sticky and very plastic; common very fine and few medium roots; common very fine and few fine tubular pores; common faint and distinct yellowish brown (10YR 5/4) clay films on faces of peds and lining pores; common distinct light gray (10YR 7/2) silt cutans on horizontal faces of peds; about 45 percent gravel; many medium and coarse masses of secondary carbonate; strongly effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (8 to 15 cm thick)

Btnk2--18 to 28 cm; pale brown (10YR 6/3) very gravelly sandy clay loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine interstitial and few very fine tubular pores; common faint clay films lining pores and very few faint clay films on faces of peds; about 50 percent gravel; common medium masses of secondary carbonate; strongly effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (8 to 15 cm thick)

R--28 cm; extremely hard lithoid tufa.

TYPE LOCATION: Churchill County, Nevada; about 12 miles north of Fallon on Upsal Hogback; approximately 2,000 feet east and 1,200 feet south of the northwest corner of section 35, T. 21 N., R. 28 E.; USGS Upsal Hogback 7.5 minute topographic quadrangle; latitude 39 degrees 38 minutes 52.05 seconds N. and longitude 118 degrees 48 minutes 25.69 seconds W.; WGS84 Decimal Degrees 39.6480556 latitude, -118.802500 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and early spring; dry in late spring through fall; Typic aridic moisture regime.
Mean annual soil temperature: 12 to 14 degrees C.
Depth to bedrock: 20 to 36 cm to a lithic contact. The underlying bedrock is lithoid tufa, a conglomerate formed along Pleistocene lakes and cemented mainly by calcium carbonate.
Salinity (EC): 8 to 32 mmhos/cm.
Sodicity (SAR) - 13 to 45.

Particle-size control section - Clay content: 25 to 35 percent;
Rock fragments: 35 to 60 percent, dominantly gravel of mixed lithology.

A horizon
Value: 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Moderately alkaline or strongly alkaline.

E horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Fine sandy loam or loamy fine sand.
Rock fragments: Less than 15 percent gravel.
Structure: Platy or massive.
Consistence: Soft or slightly hard, dry.
Reaction: Moderately alkaline or strongly alkaline.
Other features: When moist color is 4/3 or 5/3, dry color is 7/2 or 7/3; This horizon meets a criterion for albic materials and qualifies as an albic horizon.

Btn or Btnk horizons
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Very gravelly clay loam or very gravelly clay.
Clay content: 35 to 45 percent.
Rock fragments: 35 to 60 percent, mostly gravel.
Structure: Columnar or prismatic in the upper part and prismatic or subangular blocky in the lower part.
Consistence: Slightly hard to very hard, dry.
Calcium carbonate equivalent: 5 to 10 percent.
Effervescence: Strongly effervescent or violently effervescent.
Other features: Some pedons have texture of very gravelly sandy clay loam; identifiable secondary carbonates are present in some pedons as masses.

COMPETING SERIES: This is the Thompsoncabin series. Thompsoncabin soils do not have albic horizons, are dominated by cobbles, and average 60 to 80 percent rock fragments in the particle-size control section.

GEOGRAPHIC SETTING: Labou soils are on hills. They formed in lacustrine deposits derived from mixed rocks. Slopes are 2 to 15 percent. Elevations range from 1250 to 1341 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 120 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hooten and Biddleman soils. Hooten soils are very shallow to duripans and do not have natric horizons. Biddleman soils are very deep, fine-loamy over sandy or sandy-skeletal, and occur on adjacent beach terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high saturated hydraulic conductivity in the upper part of the profile and low saturated hydraulic conductivity in the lower part.

USE AND VEGETATION: Labou soils are used for livestock grazing and wildlife habitat. The present vegetation is mainly shadscale, Bailey's greasewood, bud sagebrush, and Indian ricegrass.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive with about 1,700 acres of the series mapped to date. MLRA 27.

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

SERIES ESTABLISHED: Churchill County, Nevada (Fallon-Fernley Area), 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 8 cm (A and E horizons).
Albic horizon - The zone from 3 to 8 cm (E horizon).
Natric horizon - The zone from 8 to 28 cm (Btnk1 and Btnk2 horizons).
Identifiable secondary carbonates - The zone from 8 to 28 cm (Btnk1 and Btnk2 horizons).
Lithic contact - The boundary at 28 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 28 cm (A, E, Btnk1, and Btnk2 horizons).

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National Cooperative Soil Survey
U.S.A.