LOCATION ACKETT                  ID+NV

Established Series
Rev. GHL/DA/CLM/JBF
02/2018

ACKETT SERIES

The Ackett series consists of soils that are well drained and shallow to a duripan, that formed in alluvium and colluvium derived from welded tuff. They are on stream terraces, fan piedmont remnants, partial ballenas, and lower hillsides. Slopes range from 2 to 30 percent. The average annual precipitation is about 280 mm and the average annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic, shallow Xeric Argidurids

TYPICAL PEDON: Ackett extremely gravelly clay loam - on a 2 percent, convex, east-facing slope under native rangeland vegetation at 1,710 meters elevation. (Colors are for dry soil unless otherwise noted.) When described on September 5, 1978, the soil profile was slightly moist throughout.

A1--0 to 3 cm; pale brown (10YR 6/3) extremely gravelly clay loam, brown (10YR 5/3) moist; weak medium platy structure; soft, very friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and fine vesicular pores; 60 percent gravel and 5 percent cobbles; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 10 cm thick)

A2--3 to 8 cm; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; moderate medium platy structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and fine vesicular pores; 5 percent gravel; strongly alkaline (pH 8.6); abrupt smooth boundary. (0 to 15 cm thick)

Bt--8 to 15 cm; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; weak fine prismatic structure parting to moderate medium subangular blocky; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; many distinct clay films on faces of peds and in pores; moderately alkaline (pH 8.4); abrupt wavy boundary. (8 to 10 cm thick)

2Btkq--15 to 20 cm; light gray (10YR 7/2) extremely cobbly clay, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm, moderately sticky and moderately plastic; common distinct clay films on faces of peds and in pores; many continuous silica cemented laminations throughout; fractures are 0.6 cm wide and are 20 cm apart; few very fine roots in fractures; few very fine tubular pores; 70 percent cobbles, 10 percent gravel; violent effervescence; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 8 cm thick)

2Btk--20 to 36 cm; very pale brown (10YR 7/3) very gravelly clay loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; few very fine tubular pores; common distinct clay films on faces of peds and in pores; 40 percent gravel size duripan fragments; violent effervescence (25 percent calcium carbonate); moderately alkaline (pH 8.4); abrupt smooth boundary. (8 to 18 cm thick)

2Bkqm--36 to 71 cm; white (10YR 8/1) fractured indurated duripan; very pale brown (10YR 7/3) moist; massive; many continuous silica cemented laminations throughout the duripan; fractures are 0.6 cm wide and are 50 cm apart; few very fine roots in fractures of the duripan; violent effervescence; abrupt smooth boundary. (20 to 38 cm thick)

3Bkq--71 to 127 cm; multi-colored extremely gravelly sand; single grain; loose in places; 80 percent gravel; weak carbonate-silica cementation with carbonate pendants on undersides of gravel; violent effervescence; moderately alkaline (pH 8.2); abrupt smooth boundary. (25 to 60 cm)

3R--127 cm; dark gray (7.5YR 4/1) welded tuff, very dark gray (7.5YR 3/1) moist; extremely hard; carbonate coated on upper boundary.

TYPE LOCATION: Twin Falls County, Idaho; about 17 miles southwest of Rogerson, Idaho; about 1,600 feet south and 2,300 feet east of the northwest corner section 26, T.16S., R.14E.; USGS Browns Bench South 7.5 minute topographic quadrangle; latitude 42 degrees 00 minutes 29 seconds N and longitude 114 degrees 46 minutes 59 seconds W; WGS84 Decimal Degrees 42.0080556 latitude, 42.0080556 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and early spring; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 10 degrees C.
Depth to duripan: 25 to 50 cm.
Depth to bedrock: 100 to more than 150 cm.
Fragments above duripan: Dominantly fractured indurated pan fragments Depth to carbonates: 13 to 36 cm.

Particle-size control section - Clay content: Averages 35 to 50 percent.
Rock fragments: 0 to 30 percent gravel.

A1 horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3 dry or moist.
Reaction: Slightly alkaline through strongly alkaline.

A2 horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 or 3 dry or moist.
Gravel: 30 to 60 percent.
Cobbles: 5 to 15 percent.
Reaction: Slightly alkaline through strongly alkaline.

Bt horizon
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4 dry or moist>
Texture Clay loam, clay or gravelly clay.
Clay Films: Few to many thin or moderately thick on faces of peds and in pores.
Reaction: Slightly alkaline through strongly alkaline

2Btkq and 2Btk horizons
Value: 5 to 7 dry, 4 to 7 moist.
Chroma: 2 through 4 dry or moist.
Texture: Clay loam or clay.
Modifiers: Very cobbly, extremely cobbly, very gravelly or extremely gravelly.
Clay content: 35 to 55 percent.
Coarse fragments: 40 to 80 percent with up to 45 percent cobbles. Structure grade: Weak or moderate.
Calcium carbonate: 20 to 30 percent.
Clay films: Few or common thin or moderately thick on faces of peds and in pores.
Reaction: Moderately alkaline or strongly alkaline.

2Bkqm horizon
Value: 7 or 8 dry.
Chroma: 1 through 3 dry or moist.
Distance between fractures: 38 to 76 cm.
Width of fractures: 0.6 cm or less.
Thickness of duripan: Dominantly 20 to 38 cm with some pedons up to 97 cm.

3Bkq horizon
Texture: Sand, coarse sandy loam, or sandy loam.
Modifiers: Extremely gravelly or gravelly.
Reaction: Moderately alkaline or strongly alkaline

COMPETING SERIES: These are Reina and Trosi series.

Reina and Trosi soils lack a calcic horizon above the pan.

GEOGRAPHIC SETTING: Ackett soils are on stream terraces, fan piedmont remnants, partial ballenas, and lower hillsides. Slopes are 2 to 30 percent. The soils formed in alluvium and colluvium derived from welded tuff and rhyolite with a component of volcanic ash. Elevations are 1,495 to 2,045 meters. The average annual precipitation ranges from 200 to 300 mm. The average annual temperature is 8 to 9 degrees C. The frost free season is 90 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chuska, Elhina, Isknat, and Udaho soils. Chuska soils are moderately fine textured. Chuska and Elhina soils are on higher terraces. Isknat soils are very deep and are on alluvial fans. Udaho soils occur on sideslopes and dipslopes, have a loamy-skeletal particle-size control section, and are moderately deep to welded ash.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium or rapid runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Ackett soils are used for rangeland. The native vegetation is black sagebrush, longleaf phlox, bluebunch wheatgrass, Thurber needlegrass, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Ackett soils are of moderate extent in south central Idaho and northeastern Nevada. 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 soil are:
Ochric epipedon - The zone from the soil surface to 8 cm (A1 and A2 horizons).
Argillic horizon - The zone from 8 to 36 cm (Bt, 2Btkq, and 2Btk horizons).
Calcic horizon - The zone from 15 to 36 cm (2Btkq and 2Btk horizons).
Duripan - The zone from 36 to 71 cm (2Bkqm horizon).
Particle-size control section - The zone from 8 to 36 cm (Bt, 2Btkq, and 2Btk horizons).

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National Cooperative Soil Survey
U.S.A.