LOCATION ARNESS ID+OR

Established Series
Rev. JVC-JBF
02/2018

ARNESS SERIES

The Arness series consists of shallow to a duripan, well drained soils that formed in alluvium, colluvium and residuum derived from ignimbrite, tuff, and volcanic ash. Arness soils are on structural benches and hills. Slopes are 1 to 20 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Argiduridic Durixerolls

TYPICAL PEDON: Arness sandy loam--on a 2 percent slope at 1,620 meters elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described on June 6, l982, the soil was slightly moist throughout.)

A--0 to 5 cm; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; many very fine irregular pores; neutral (pH 6.7); clear smooth boundary. (3 to 10 cm thick)

AB--5 to 15 cm; brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; many very fine irregular pores; neutral (pH 6.7); gradual wavy boundary. (0 to 20 cm thick)

Bt1--15 to 30 cm; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common fine roots; many very fine irregular pores; few faint clay films on faces of peds and lining pores; neutral (pH 7.0); clear smooth boundary. (8 to 20 cm thick)

Bt2--30 to 48 cm; pale brown (10YR 6/3) sandy clay loam, brown (10YR 4/3) moist; strong medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; common very fine to medium roots; common very fine irregular pores; common distinct clay films on faces of peds and lining pores; slightly alkaline (pH 7.7); abrupt smooth boundary. (0 to 20 cm thick)

Bqkm--48 to 81 cm; white (10YR 8/1) cemented material, very pale brown (10YR 7/3) moist; strong medium and thick platy structure; extremely hard, extremely firm; indurated by opal in laminar cap less than 1.3 cm thick; many 0.2 to 0.6 cm thick carbonate and opal-cemented lenses mixed with ignimbrite sand and gravel; few very fine and few fine roots in fractures; fractures are 0.6 cm wide and 20 cm apart; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (3 to 50 cm thick)

2R--81 cm; black (10YR 2/1) ignimbrite (densely welded, vitric ash-flow tuff).

TYPE LOCATION: Twin Falls County, Idaho; about 16 miles west of Rogerson; about 830 feet south and 1,870 feet west of the northeast corner of section 23, T. 14 S., R. 13 E.; USGS Cedar Creek Reservoir 7.5 minute topographic quadrangle; latitude 42 degrees 11 minutes 56 seconds N and longitude 114 degrees 53 minutes 53 seconds W; WGS84 Decimal Degrees 42.1988889 latitude, -114.8980556 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry in summer and early fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 30 cm; includes the Bt1 horizon in most pedons.
Depth to base of argillic horizon: 30 to 50 cm.
Depth to duripan: 30 to 50 cm.
Depth to bedrock: 50 to 100 cm to a lithic contact.

Particle-size control section - Clay content: 22 to 35 percent.
Rock fragments: 0 to 20 percent gravel and 0 to 10 percent cobbles. Lithology of fragments are ignimbrite or tuff.

A horizon
Value: 4 through 6 dry, 2 or 3 moist; dry value is 4 or 5 when the upper 18 cm of the soil is mixed.
Chroma: 2 or 3, dry or moist.
Rock fragments: 0 to 15 percent gravel, 0 to 5 percent cobbles, 0 to 15 percent stones.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 to 3 percent.

AB horizon (when present)
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loam, gravelly loam, or cobbly loam
Clay content: 16 to 26 percent.
Rock fragments: 0 to 30 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 to 3 percent.

Bt1 horizon
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Sandy clay loam, gravelly sandy clay loam, gravelly clay loam, cobbly clay loam, or clay loam.
Rock fragments: 0 to 20 percent gravel and 0 to 10 percent cobbles.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 or 1.5 percent.

Bt2 horizon (when present)
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Sandy clay loam, gravelly sandy clay loam, or clay loam.
Rock fragments: 0 to 20 percent gravel.
Reaction: Neutral or slightly alkaline.

Bqkm horizon - Thickness of laminar cap: less than 1.3 cm.
Cementation class: Indurated or very strongly cemented in laminar cap; weakly to strongly cemented below laminar cap.
Fractures: 0.6 to 2.5 cm wide, 15 to 50 cm apart.

COMPETING SERIES: These are the Blayden and Vil series.

Blayden and Vil soils are greater than 150 cm deep to bedrock. In addition, Vil soils have duripans that are 50 to 100 cm thick.

GEOGRAPHIC SETTING: Arness soils are on structural benches and hills. These soils formed in alluvium residuum or colluvium derived from ignimbrite, tuff, and volcanic ash. Slopes are 1 to 20 percent. Elevations range from 1,400 to 1,800 meters. The mean annual precipitation is 280 to 330 mm, the mean annual temperature is 6 to 8 degrees C., and the frost-free period is 50 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chuska, Lud, Mug, and Tock soils. Chuska soils occur on lower surfaces and have mesic temperature regime. Lud soils are fine. Mug soils are clayey-skeletal and are moderately deep to tuff. Tock soils are fine and are moderately deep to duripans.

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

USE AND VEGETATION: Arness soils are used for rangeland and wildlife habitat. The native vegetation is basin big sagebrush, bluebunch wheatgrass, and Sandberg's bluegrass.

DISTRIBUTION AND EXTENT: Southern Idaho and south-central Oregon. These soils are not extensive with about 6,900 acres of the series mapped to date. The series concept and main acreage is in MLRA 25 in Idaho, while other acreage occurs in MLRA 23 in Oregon.

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

SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 30 cm (A, AB, and Bt1 horizons).
Argillic horizon - The zone from 15 to 48 cm (Bt1 and Bt2 horizons).
Duripan - The zone from 48 to 81 cm (Bqkm horizon).
Lithic contact - The boundary at 81 cm to underlying hard bedrock (2R layer).
Particle-size control section - The zone from 15 to 48 cm (Bt1 and Bt2 horizons).

ADDITIONAL DATA: Base saturation: 0-5 cm - 65 percent; 5-15 cm - 75 percent; 15-30 cm - 66 percent; 30-48 cm 83 percent. Clay percent by hydrometer: 0-5 cm - 14 percent; 5-15 cm - 18 percent; 15-30 cm - 22 percent; 30-48 cm - 24 percent.

National Cooperative Soil Survey
U.S.A.