LOCATION HECKISON                ID+NV

Established Series
Rev. JVC/JBF
01/2019

HECKISON SERIES

The Heckison series consists of moderately deep to a duripan, well drained soils that formed in loess and alluvium derived from basalt and volcanic ash. Heckison soils are on calderas, plug domes, plateaus, and hills. Slopes are 1 to 15 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Argiduridic Durixerolls

TYPICAL PEDON: Heckison silt loam--on a nearly level area of a caldera at 1,631 meters elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described on June 4, 1981, the soil was dry from 0 to 8 cm, slightly moist from 8 to 43 cm, and dry below.)

A--0 to 10 cm; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine tubular and interstitial pores; neutral (pH 6.9); clear smooth boundary. (8 to 25 cm thick)

Bt1--10 to 18 cm; yellowish brown (10YR 5/4) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine, few medium roots; many very fine and many fine tubular pores; few faint clay films on faces of peds; neutral (pH 7.0); clear smooth boundary. (8 to 25 cm thick)

Bt2--18 to 48 cm; yellowish brown (10YR 5/4) silty clay loam, dark brown (10YR 3/3) moist; strong fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine, fine and medium, few coarse roots; many very fine, common fine, and few medium tubular pores; many distinct clay films on faces of peds and lining pores; 10 percent cobbles; neutral (pH 7.1); clear wavy boundary. (0 to 30 cm thick)

Bk--48 to 74 cm; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; massive; hard, firm, slightly sticky and nonplastic; few very fine and fine roots; few very fine tubular pores; 10 percent gravel; strongly effervescent; secondary carbonates segregated as coats on rock fragments; moderately alkaline (pH 8.0); abrupt wavy boundary. (13 to 50 cm thick)

Bkqm--74 to 89 cm; yellowish brown (10YR 5/4) and very pale brown (10YR 8/2) cemented material, very pale brown (10YR 7/3) and very pale brown (10YR 8/2) moist; continuous, indurated prominent laminae of opaline silica 2 mm thick over 15 percent cobbles; violently effervescent; abrupt wavy boundary. (3 to 40 cm thick)

2R--89 cm; basalt.

TYPE LOCATION: Owyhee County, Idaho; about 13 miles north of Murphy Hot Springs; about 2,000 feet north and 700 feet west of the southeast corner of section 15, T. 14 S., R. 9 E.; USGS Poison Butte 7.5 minute topographic quadrangle; latitude 42 degrees 12 minutes 27 seconds N and longitude 115 degrees 23 minutes 12 seconds W; WGS84 Decimal Degrees 42.2075000 latitude, -115.3866667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry from summer to early fall; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mean summer soil temperature: 18 to 19 degrees C.
Mollic epipedon thickness: 18 to 48 cm; includes the Bt horizons.
Depth to calcic horizon: 30 to 50 cm.
Depth to duripan: 53 to 90 cm.
Depth to bedrock: 56 to 100 cm to a lithic contact.

Particle-size control section - Clay content: 24 to 35 percent.

A horizon
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 or 3 percent.
Reaction: Neutral or slightly alkaline.

Bt horizons
Value: 4 through 6 dry, 2 through 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Silt loam or silty clay loam.
Clay content: 24 to 35 percent.
Rock fragments: 0 to 15 percent.
Organic matter content: 1 or 2 percent.
Reaction: Neutral through moderately alkaline.
Other features: Some pedons have identifiable secondary carbonates or texture of loam; pedons with higher value and chroma are in lower subhorizons below the mollic epipedon.

Bk horizon
Value: 6 through 8 dry, 4 through 7 moist.
Chroma: 1 through 4, dry or moist.
Texture: Silt loam, very fine sandy loam, or gravelly silt loam.
Clay content: 10 to 20 percent.
Rock fragments: 5 to 35 percent.
Calcium carbonate equivalent: 15 to 25 percent.
Reaction: Slightly alkaline through strongly alkaline.
Other features: Some pedons have up to 80 percent detached duripan fragments that are gravel and cobble-size.

COMPETING SERIES: This is the Gradon series. Gradon soils do not have calcic horizons above the duripan and do not have lithic contacts within 150 cm of the soil surface.

GEOGRAPHIC SETTING: Heckison soils are on calderas, plug domes, plateaus, and hills. These soils formed in loess and alluvium derived from basalt and volcanic ash. Slopes are 1 to 15 percent. Elevations range from 1,525 to 2,045 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 360 mm, the mean annual temperature is 6 to 8 degrees C, and the frost-free period is 75 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bigflat, Dishpan, and Insidert soils. Bigflat and Dishpan soils do not have duripans. Insidert soils have more than 35 percent clay in the particle-size control section. These soils are on similar landscapes.

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

USE AND VEGETATION: Heckison soils are used mainly for rangeland and wildlife habitat. The dominant vegetation is Wyoming big sagebrush, bluebunch wheatgrass, Sandberg's bluegrass, and western wheatgrass.

DISTRIBUTION AND EXTENT: Southwestern Idaho and northeastern Nevada. These soils are moderately extensive. MLRA 25.

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

SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 48 cm (A, Bt1 and Bt2 horizons).
Argillic horizon - The zone from 10 to 48 cm (Bt1 and Bt2 horizons).
Calcic horizon - The zone from 48 to 74 cm (Bk horizon).
Duripan - The zone from 74 to 89 cm (Bkqm horizon).
Lithic contact - The boundary at 89 cm to underlying hard, unweathered bedrock (2R layer).
Particle-size control section - The zone from 10 to 48 cm (Bt1 and Bt2 horizons).

ADDITIONAL DATA: Previous authors and editors include: DBJ-ALH-CLM.

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National Cooperative Soil Survey
U.S.A.