LOCATION TURBA                   NV

Established Series
Rev. DJM/RLB/JVC
07/2016

TURBA SERIES

The Turba series consist of shallow, well drained soils that formed in residuum and colluvium derived from welded tuff. Turba soils are on mountains. Slopes are 8 to 30 percent. The mean annual precipitation is 350 mm and the mean annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Vitritorrandic Argiustolls

TYPICAL PEDON: Turba very gravelly ashy sandy loam--forest land. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 10 percent cobbles and 40 percent gravel.

Oi--0 to 1 cm; slightly decomposed plant material of pinyon needles and oak leaf litter.

A1--1 to 5 cm; brown (10YR 5/3) very gravelly ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine and fine interstitial pores; 5 percent cobbles and 40 percent gravel; neutral (pH 6.8); clear smooth boundary.

A2--5 to 18 cm; dark grayish brown (10YR 4/2) gravelly ashy sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, moderately sticky and slightly plastic; common very fine and fine and few medium roots; common very fine interstitial and few very fine tubular pores; 2 percent cobbles and 20 percent gravel; neutral (pH 6.8); clear smooth boundary. (Combined thickness of A horizons is 5 to 25 cm thick)

Bt1--18 to 28 cm; brown (7.5YR 5/2) very gravelly ashy sandy clay loam, brown (7.5YR 4/2) moist; strong fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; common very fine and fine and few medium and coarse roots; common very fine tubular pores; many distinct clay films lining pores; few pressure cutans on faces of peds; 5 percent cobbles and 35 percent gravel; neutral (pH 7.0); clear wavy boundary. (10 to 23 cm thick)

Bt2--28 to 41 cm; brown (7.5YR 5/4) very gravelly ashy sandy clay loam, brown (7.5YR 4/4) moist; strong fine and medium angular blocky structure; hard, firm, very sticky and very plastic; common very fine and fine and few medium and coarse roots; common very fine tubular pores; many distinct clay films lining pores; many pressure cutans on faces of peds; 5 percent cobbles and 45 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (Combined thickness of Bt horizons is 18 to 48 cm thick)

Cr--41 cm; weathered welded tuff.

TYPE LOCATION: Lincoln County, Nevada; in the Clover Mountains about 1 mile northwest of Samscamp Spring; approximately 2,225 feet east and 625 feet south of the northwest corner of section 24, T. 7 S., R. 69 E.; USGS Jacks Mountain 7.5 minute topographic quadrangle; latitude 37 degrees 19 minutes 52 seconds N and longitude 114 degrees 13 minutes 23 seconds W; WGS84 Decimal Degrees 37.3311111 latitude, -114.2230556 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section during winter and early spring months; intermittently moist in some part from early July through early October; aridic soil moisture regime that borders ustic.
Mean annual soil temperature: 8 to 11 degrees C.
Mollic epipedon thickness: 16 to 25 cm, some pedons meet mollic criteria when mixed.
Depth to bedrock: 36 to 50 cm to a paralithic contact.
Reaction: Slightly acid or neutral.

Particle-size control section - Clay content: 27 to 35 percent.
Rock fragments: 35 to 60 percent.
Mineralogy: 15 to 25 percent volcanic glass in the 0.2 to 2 mm fraction and averages 0.1 to 0.25 percent Al plus 1/2Fe, extracted by ammonium oxalate.

A horizons
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 4 or 5 percent.
Mineralogy: 15 to 24 percent volcanic glass in the 0.2 to 2 mm fraction and averages 0.01 to 0.09 percent Al plus 1/2Fe, extracted by ammonium oxalate.

Bt horizons
Hue: 7.5YR or 10YR.
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Rock fragments: average 35 to 60 percent and are dominantly 2 to 5 mm size gravel.
Texture: Very gravelly ashy sandy clay loam or very cobbly ashy sandy clay loam.
Structure: Strong or moderate fine and medium subangular, angular blocky or prismatic structure.
Consistence: Slightly hard or hard.
Organic matter content: 1 to 3 percent.

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

GEOGRAPHIC SETTING: Turba soils are on mountains. These soils formed in residuum and colluvium derived from welded tuff. Slopes are 8 to 30 percent. Elevations range from 1,850 to 2,150 meters. The climate is sub-humid with cool, moist winters and warm, intermittently moist summers. The mean annual precipitation is 350 to 400 mm, the mean annual air temperature is 7 to 11 degrees C, and the frost-free period is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acti, Cederan, and Motoqua soils. Acti and Cederan soils average greater than 35 percent clay in the particle-size control section. Motoqua soils have a moderate permeability and are commonly located on convex mountain backslopes.

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

USE AND VEGETATION: Turba soils are used for livestock grazing and wildlife habitat. Potential native vegetation is a forest canopy of singleleaf pinyon and Utah juniper with a minor understory of turbinella oak, Gambels oak, mountain big sagebrush, Utah serviceberry, greenleaf manzanita, Mojave ceanothus, muttongrass, and prairie junegrass. This pedon is correlated to ecological site PIMO-JUOS WSG, F029XY078NV.

DISTRIBUTION AND EXTENT: Southeastern Nevada. These soils are moderately extensive. MLRA 29.

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

SERIES ESTABLISHED: Lincoln County, Nevada, South Part, 1992.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 1 to 18 cm (A1 and A2 horizons).
Vitritorrandic feature - 20 to 25 percent volcanic glass in the 0.2 to 2 mm fraction and ranges from 0.1 to 0.2 percent Al plus 1/2Fe, extracted by ammonium oxalate between 18 to 41 cm (Bt1, and Bt2 horizons).
Argillic horizon - The zone from 18 to 41 cm (Bt1 and Bt2 horizons).
Paralithic contact - The boundary at 41 cm (Cr layer).
Particle-size control section - The zone from 18 to 41 cm (Bt1 and Bt2 horizons).

ADDITIONAL DATA: Characterization data (S86NV-017-009) collected on a similar pedon was used to develop this series concept.

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National Cooperative Soil Survey
U.S.A.