LOCATION BOSO                    NV

Established Series
Rev. DWW-RLB-JBF
10/2018

BOSO SERIES

The Boso series consists of shallow, well drained soils that formed in alluvium derived mainly from limestone, dolostone and quartzite. The Boso soils are on summits and side slopes of fan piedmont remnants. Slopes are 4 to 15 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid, shallow Petrocalcidic Palexerolls

TYPICAL PEDON: Boso loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 15 percent gravel.

A1--0 to 10 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium and coarse subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and few fine roots; many very fine interstitial pores; 10 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (8 to 13 cm thick)

A2--10 to 23 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; common medium thick carbonate pendants on lower sides of gravel; 10 percent fragments consisting of gravel and gravel size pan fragments; slightly alkaline (pH 7.8); clear smooth boundary. (10 to 15 cm thick)

Bk--23 to 48 cm; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common fine, few medium and coarse roots; common very fine and fine tubular pores; many thick carbonate pendants on lower sides of gravel; 40 percent coarse fragments consisting of gravel and gravel-size pan fragments; 6 percent calcium carbonate equivalent on the less than 2 mm fraction; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (8 to 28 cm thick)

Bkm--48 to 86 cm; very pale brown (10YR 8/2) indurated petrocalcic, with 1 to 8 mm laminar carbonate cap, and a few discontinuous 8 to 25 cm thick pockets of brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; massive; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (30 to 69 cm thick)

2Bky--86 to 100 cm; very pale brown (10YR 7/3) gravelly loam, yellowish brown (10YR 5/4) moist; massive; hard, friable, slightly sticky and slightly plastic; many thick carbonate coatings on gravel; weakly carbonate cemented; 15 percent gravel; many very fine and fine gypsum filaments; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (13 to 25 cm thick)

3Bky--100 to 150 cm; light gray (10YR 7/2) extremely gravelly loam, grayish brown (10YR 5/2) moist; massive; hard, friable, slightly sticky and plastic; many thick carbonate coats on gravel; common very fine and fine gypsum filaments; weakly carbonate cemented; 65 percent gravel; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Elko County, Nevada; approximately 30 miles north of Wells, about 3,200 feet west of the northeast corner, sec. 31, T. 42 N., R. 61 E.; USGS Black Butte NE 7.5 minute topographic quadrangle; latitude 41 degrees 29 minutes 45 seconds N and 115 degrees 07 minutes 07 seconds longitude; WGS84 Decimal Degrees 41.4958333 latitude, -115.1186111 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist, moist in winter and spring, dry from mid-June through early October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 25 to 50 cm.
Depth to petrocalcic horizon: 25 to 50 cm.

Particle-size control section - Clay content: 18 to 27 percent.
Rock fragments: 35 to 50 percent mainly gravel and gravel size pan fragments.

A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.

Bk horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.
Texture: Very gravelly loam or very gravelly silt loam.
Clay content: 18 to 27 percent.
Rock fragments: 35 to 50 percent gravel and gravel size pan fragments.
Carbonates: 5 to 15 percent.
Reaction: Slightly alkaline or moderately alkaline.

Bkm horizon
Value: 7 or 8 dry.

Bky horizon
Texture: Loam or extremely gravelly loam.
Clay content: 10 to 18 percent.
Rock fragments: 5 to 75 percent, mainly gravel.
Reaction: Moderately alkaline or strongly alkaline.
Gypsum filaments: Few to many in any one subhorizon.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Boso soils are on summits and side slopes of fan piedmont remnants. These soils formed in alluvium derived mainly from dolostone, limestone and quartzite. Slopes are 4 to 15 percent. Elevations are 1,680 to 2,015 meters. The climate is cool, semiarid with warm, dry summers and cool, moist winters. The mean annual precipitation is 250 to 360 mm; mean annual temperature is 5 to 8 degrees C, and the frost-free season is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dewar, Donna, Hunnton and Stampede soils. All of these soils lack petrocalcic horizons and have less than 35 percent rock fragments. In addition Donna, Hunnton and Stampede soils have more than 35 percent clay in the particle-size control section.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly mountain big sagebrush, antelope bitterbrush, Idaho fescue and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Northeast Nevada. These soils are not extensive. MLRA 25.

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

SERIES ESTABLISHED: Elko County, Nevada, northeast part, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 48 cm (A1, A2 and Bk horizons)
Petrocalcic horizon - The zone from 48 to 86 cm (Bkm horizon)
Particle-size control section - The zone from 25 to 48 cm (part of the Bk horizon).

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National Cooperative Soil Survey
U.S.A.