LOCATION BOOST                   OR

Tentative Series
Rev. ARR/TM
10/2018

BOOST SERIES

The Boost series consists of moderately deep, moderately well drained soils that formed in mixed volcanic ash and loess over residuum weathered from tuff and basalt. Boost soils are on lava plateaus and hillslopes. Slopes are 2 to 35 percent. The mean annual precipitation is about 350 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Vitrandic Argixerolls

TYPICAL PEDON: Boost ashy silt loam at an elevation of 1,435 meters, rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partly covered by 1 percent gravel.

A--0 to 15 cm; grayish brown (10YR 5/2) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak fine, medium and coarse granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine roots; common very fine tubular pores; neutral (pH 7.2); clear smooth boundary. (5 to 20 cm thick)

Bt1--15 to 26 cm; brown (10YR 5/3) ashy silty clay loam, dark brown (10YR 3/3) moist; strong fine subangular blocky structure; hard, firm, slightly sticky, slightly plastic; common fine and very fine roots; common very fine tubular pores; 20 percent clay bridges; slightly alkaline (pH 7.4); clear smooth boundary. (7 to 20 cm thick)

Bt2--26 to 40 cm; brown (10YR 4/3) clay, brown (10YR 4/3) moist; strong fine angular blocky structure; very hard, very firm, moderately sticky, moderately plastic; common fine and very fine roots; common fine and very fine tubular pores; 10 percent clay films on all faces of peds and 40 percent clay bridges; slightly alkaline (pH 7.4); clear smooth boundary. (10 to 20 cm thick)

BCt--40 to 56 cm; brown (10YR 4/3) paragravelly clay, brown (10YR 4/3) moist; strong fine angular blocky structure; very hard, very firm, moderately sticky, moderately plastic; common fine and very fine roots; common very fine tubular pores; 30 percent clay films on all faces of peds; 15 percent moderately cemented tuff paragravel; slightly alkaline (pH 7.4); clear smooth boundary. (0 to 20 cm thick)

Cr--56 cm; moderately cemented tuff.

TYPE LOCATION: Malheur County, Oregon; 10 miles south of Jordan Valley, Oregon; ; about 1,800 feet south and 340 feet west of the northeast corner of section 12, T. 32 S., R 45 E.; USGS Juniper Ridge 7.5 minute quadrangle, latitude 42 degrees 47 minutes 4.44 seconds north and longitude 117 degrees, 7 minutes, 50.77 seconds west, WGS84 Decimal Degrees 42.7845667 latitude, -117.1307694 longitude.

RANGE IN CHARACTERISTICS:

Soil moisture - The soil moisture control section is dry throughout in late summer and fall and moist in winter, spring, and early summer; the soil surface is wet in April due to snowmelt; xeric soil moisture regime.
Soil temperature - The mean annual soil temperature is 7 to 8 degrees C.
Mollic epipedon thickness - 25 to 50 cm, includes the upper part of the Bt horizon in some pedons.
Depth to paralithic contact - 50 to 80 cm.

Control section - Clay content: 40 to 45 percent.
Rock fragments: 2 to 20 percent, mainly gravel with tuff lithology.

A horizon -
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3 dry or moist.
Volcanic glass: Volcanic glass is estimated to range from 30 to 50 percent of the 0.02 to 2 mm fraction.

Bt1 horizon -
Value: 4 or 5 dry and 2 or 4 moist.
Chroma: 2 to 4 dry or moist.
Texture: Ashy silty clay loam, ashy clay loam, ashy silt loam.
Clay content: 25 to 35 percent.
Rock fragments: Averages 5 to 30 percent, mainly cobbles.
Volcanic glass: Volcanic glass is estimated to range from 5 to 30 percent of the 0.02 to 2 mm fraction.

Bt2 horizon -
Value: 4 to 6 dry and 2 to 4 moist.
Chroma: 2 to 4 dry or moist.
Texture: Clay, silty clay loam
Clay content: 35 to 50 percent.
Rock fragments: Averages 5 to 30 percent, mainly cobbles.
Reaction: Neutral through slightly alkaline.

BCt horizon (when present)
Value: 3 or 4, moist or dry.
Chroma: 3 or 4, moist or dry.
Clay content: 40 to 50 percent.
Rock fragments: Averages 15 to 30 percent, mainly paragravel of tuff lithology.

COMPETING SERIES: These are the Volstead soils. The Volstead soils are greater than 100 cm to lithic contacts.

GEOGRAPHIC SETTING: Boost soils are on lava plateaus and hillslopes. These soils formed in mixed volcanic ash and loess over residuum weathered from tuff and basalt. Slopes are 2 to 35 percent. Elevations are 1,430 to 1,585 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 mm; mean annual temperature is 5 to 7 degrees C, and the frost free season is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fastjet soils. Fastjet soils have less than 35 percent clay in the argillic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained, very slow permeability, and low saturated hydraulic conductivity.

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

DISTRIBUTION AND EXTENT: Southeast Oregon; the soil is of small extent. MLRA 25.

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

SERIES PROPOSED: Malheur County, Oregon, Southern Part 2008.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - The zone from the soil surface to about 26 cm (A and Bt1 horizons).

Argillic horizon - The zone from about 15 to 40 cm (Bt1 and Bt2 horizons).

Vitrandic feature - Volcanic glass is 30 to 50 percent of the 0.02 to 2 mm fraction in the zone from 0 to 15 cm (A horizons). Volcanic glass is 5 to 30 percent of the 0.02 to 2 mm fraction in the zone from 15 to 26 cm (Bt1 horizon).

Particle-size control section - the zone from 15 to 40 cm (Bt1 and Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.