LOCATION CHUSKA ID+NV UTEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Xeric Argidurids
TYPICAL PEDON: Chuska gravelly loam - on a 2 percent, convex, south facing slope, under native rangeland, at 5,320 feet elevation. (Colors are for air-dry soil unless otherwise stated. When described on September 7, 1978, the soil profile was slightly moist throughout.)
A--0 to 3 inches; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 4/3) moist; weak medium platy structure; soft, friable, slightly sticky and slightly plastic; common roots; many very fine and fine vesicular pores; 25 percent gravel; moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 6 inches thick)
Bt1--3 to 7 inches; pale brown (10YR 6/3) clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine through medium roots; many very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 10 percent gravel; moderately alkaline (pH 8.2); abrupt smooth boundary. (3 to 10 inches thick)
Bt2--7 to 10 inches; pale brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 10 percent gravel size pan fragments; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 5 inches thick)
Btk--10 to 14 inches; very pale brown (10YR 7/4) gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; common very fine tubular pores; common faint clay films on faces of peds and in pores; 25 percent gravel size duripan fragments; violently effervescent (20 percent calcium carbonate equivalent); strongly alkaline (pH 8.6); abrupt smooth boundary. (0 to 7 inches thick)
Bkqm--14 to 18 inches; white (10YR 8/2) fractured indurated duripan, light yellowish brown (10YR 6/4) moist; massive; extremely hard, extremely firm; many continuous silica cemented laminations throughout the duripan; few very fine roots in fractures of the duripan; fractures are 1/4 inch wide and are 10 inches apart; violently effervescent; abrupt smooth boundary. (4 to 12 inches thick)
2Bkq--18 to 29 inches; very pale brown (10YR 7/3) extremely gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; very hard, very firm, nonsticky and nonplastic; few very fine and fine roots; few very fine and fine tubular pores; 50 percent gravel and 20 percent gravel size pan fragments; gravel lime coated with lime pendanting on undersides; weakly cemented matrix; violently effervescent (25 percent calcium carbonate equivalent); strongly alkaline (pH 8.6); abrupt wavy boundary. (6 to 15 inches thick)
2Bk--29 to 51 inches; very pale brown (10YR 7/4) extremely gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; few very fine tubular pores; 60 percent gravel, 15 percent cobbles; gravel and cobbles lime coated with lime pendanting on undersides; violently effervescent (25 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); abrupt smooth boundary. (15 to 25 inches thick)
3R--51 inches; light yellowish brown (10YR 6/4) welded tuff, yellowish brown (10YR 5/4) moist; extremely hard; lime coated on upper boundary.
TYPE LOCATION: Twin Falls County, Idaho; about 8 miles south of Rogerson, Idaho, about 1600 feet east and 50 feet north from the southwest corner of section 10, T. 15S., R. 15E. Latitude - 42 degrees, 07 minutes, 13 seconds North; Longitude - 114 degrees, 41 minutes, 11 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 52 degrees F. Depth to calcium carbonate - 7 to 14 inches Depth to duripan - 12 to 20 inches Depth to bedrock - 40 to more than 60 inches Control section Clay content - 26 to 35 percent
A horizon Value - 5 or 6 dry, 3 or 4 moist Chroma - 2 or 3 dry or moist Structure Type - granular or platy
Bt horizons Hue - 10YR or 7.5YR Value - 5 or 6 dry, 3 or 4 moist Chroma - 2 through 4 dry or moist Texture - CL, GR-CL, GR-L, SCL Gravel - 5 to 35 percent (includes duripan fragments) Reaction - moderately or strongly alkaline Effervescence - none through violent
Bkqm Thickness of first silica lamination - 1 to 3 inches Thickness of subsequent laminations - 1/2 to 2 inches
Bkq and Bk horizons Hue - 10YR or 7.5YR Value - 6 or 7 dry, 5 or 6 moist Chroma - 3 to 6 dry or moist Texture - GRX-SL, GRV-CL Rock fragments - 35 to 75 percent Reaction - moderately alkaline to strongly alkaline
COMPETING SERIES: These are the Acana, Argalt, Ayres, Bartome (T), Bruncan (T), Chuckridge, Colthorp, Dewar (T), Grassval (T), Handpah (T), Packwood, Pipeline, Roseworth, Thoms and Wellington soils. Acana, Bartome and Chuckridge soils have less than 26 percent clay for the average of the control section. Agalt, Bruncan, Colthorp, and Packwood soils have bedrock above 40 inches. Ayres, Thoms and Wellington are neutral or slightly acid in the control section. Dewar and Grassval soils are effervescent in the entire argillic horizon. Handpah soils have soil temperatures warmer than 53 degrees F. Pipeline and Roseworth soils have silty clay loam or silt loam textures in the Bt horizons.
GEOGRAPHIC SETTING: Chuska soils are on terraces, dipslopes, hills, ridges and fan remnants. Slopes range from 1 to 25 percent. The soil formed in old alluvium from welded tuff and flow rock. Elevation ranges from 3,500 to 6,200 feet. The average annual precipitation is about 9 to 12 inches. The average annual air temperature is about 45 to 51 degrees F. The frost-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ackett, Lud, Udaho and Weash soils. Ackett soils are fine textured. Lud soils have fine textured argillic horizons. Udaho soils are loamy-skeletal. Weash soils have ashy mineralogy. Ackett and Weash soils occur on lower terraces. Lud soils occur on higher terraces. Udaho soils occur on sideslopes.
DRAINAGE AND PERMEABILITY: Well drained; slow through medium runoff; moderately slow permeability.
USE AND VEGETATION: Chuska soils are used for rangeland and irrigated cropland. The native vegetation is Wyoming big sagebrush, basin big sagebrush, bluebunch wheatgrass, Thurber needlegrass and Indian ricegrass. The principal crops grown are wheat, barley and alfalfa hay.
DISTRIBUTION AND EXTENT: Southcentral Idaho and northeastern Nevada. This series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.
REMARKS: This revision (8/95) changes the classification from Xerollic Durargids to Xeric Argidurids according to the 1994 edition of Keys to Soil Taxonomy. The competing series section has not been updated.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to 3 inches (A horizon)
Argillic horizon - the zone from 3 to 14 inches (Bt horizon)
Calcic horizon - the zone from 10 to 18 inches (Btk and Bkqm horizons)
The duripan - the zone from 14 to 18 inches (Bkqm horizon)