LOCATION ACKETT ID+NVEstablished Series
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 5,600 feet 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 1 inches; pale brown (10YR 6/3) extremely gravelly clay loam, brown (10YR 5/3) moist; weak medium platy structure; soft, friable, sticky and 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. (1 to 4 inches thick)
A2--1 to 3 inches; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; moderate medium platy structure; slightly hard, friable, sticky and 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 6 inches thick)
Bt--3 to 6 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; weak fine prismatic structure parting to moderate medium subangular blocky; hard, firm, sticky and 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. (3 to 4 inches thick)
2Btkq--6 to 8 inches; light gray (10YR 7/2) extremely cobbly clay, very pale brown (10YR 7/3) moist; massive; extremely hard, extremely firm; common distinct clay films on faces of peds and in pores; many continuous silica cemented laminations throughout; fractures are 1/4 inch wide and are 8 inches apart; few very fine roots in fractures; 70 percent cobbles, 10 percent gravel; violent effervescence; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 3 inches thick)
2Btk--8 to 14 inches; very pale brown (10YR 7/3) very gravelly clay loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; hard, firm, sticky and 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. (3 to 7 inches thick)
2Bkqm--14 to 28 inches; 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 1/4 inch wide and are 20 inches apart; few very fine roots in fractures of the duripan; violent effervescence; abrupt smooth boundary. (8 to 15 inches thick)
3Bkq--28 to 50 inches; multi-colored extremely gravelly sand; single grain; loose in places; weak lime-silica cementation with lime pendants on undersides of gravel; violent effervescence; abrupt smooth boundary. (10 to 24 inches thick)
R--50 inches; dark gray (7.5YR N 4/0) welded tuff, very dark gray (7.5YR N 3/0) moist; extremely hard; lime coated on upper boundary.
TYPE LOCATION: Twin Falls County, Idaho; about 17 miles southwest of Rogerson, Idaho; SE1/4, SE1/4, NW1/4 section 26,T.16S., R.14E.
RANGE IN CHARACTERISTICS:
Depth to duripan - 10 to 20 inches
Depth to bedrock - 40 to more than 60 inches
Average annual soil temperature - 47 degrees to 50 degrees F. Fragments above duripan - dominantly fractured indurated pan fragments Depth to carbonates - 5 to 14 inches
A 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 - CL, C, or GR-CL
Clay content - 35 to 50 percent
Gravel - 0 to 30 percent
Clay Films
Frequency - few to many
Thickness - thin or moderately thick
Morphology - on faces of peds and in pores
Reaction - mildly alkaline through strongly alkaline
2Btkq and 2Btk horizons
Value - 5 to 7 dry, 4 to 7 moist
Chroma - 2 to 4 dry or moist
Texture - CBV-C, CBX-C, CBV-CL, CBX-CL, GRX-C, GRX-CL, GRV-CL
Clay content - 35 to 55 percent
Structure Grade - weak or moderate
Calcium carbonate - 20 to 30 percent
Clay films
Frequency - few or common
Thickness - thin or moderately thick
Morphology - faces of peds and in pores
Coarse fragments - 40 to 80 percent with up to 45 percent cobbles Reaction - moderately alkaline to strongly alkaline
2Bkqm horizon
Value - 7 or 8 dry
Chroma - 1 through 3 dry or moist
Distance between fractures - 15 to 30 inches
Width of fractures - 1/4 inch or less
Thickness of duripan - dominantly 8 to 15 inches with some pedons up to 38 inches
3Bkq horizon
Texture - GRX-S, COSL, GR-COSL, and GR-SL
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. Reina soils have bedrock above 40 inches. Trosi soils are slightly acid.
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 old alluvium and colluvium from welded tuff and rhyolite with a component of volcanic ash. Elevations are 4,900 to 6,700 feet. The average annual precipitation ranges from 8 to 12 inches. The average annual temperature is 46 to 49 degrees F. 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 PERMEABILITY: Well drained; medium or rapid runoff; very slow permeability.
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 OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Elko County, Nevada, Northeast Part, 1986.
REMARKS: Diagnostic horizons and features recognized in this soil are:
Ochric epipedon - 0 to 3 inches (A1 and A2 horizons)
Argillic horizon - 3 to 14 inches including an old degrading duripan at 6 to 8 inches depth (Bt, 2Btkq, and 2Btk horizons)
Calcic horizon - 6 to 14 inches (2Btkq and 2Btk horizons)
Duripan - at 14 inches (2Bkqm horizon)