LOCATION DEHANA IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Pachic Argicryolls
TYPICAL PEDON: Dehana gravelly loam - on a southeast facing slope of 16 percent under rangeland vegetation at 7,400 feet elevation. (Colors are for air-dry soil unless otherwise stated. When described on August 17, 1981, the soil was dry throughout.)
A--0 to 6 inches; very dark grayish brown (10YR 3/2) gravelly loam, very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many fine and very fine tubular pores; 25 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (4 to 20 inches thick)
Bt1--6 to 15 inches; dark grayish brown (10YR 4/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many fine and very fine tubular pores; common faint clay films on faces of peds and in pores; 25 percent gravel; slightly acid (pH 6.2); gradual wavy boundary. (6 to 22 inches thick)
Bt2--15 to 30 inches; brown (10YR 4/3) gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common roots; many fine and very fine tubular pores; common faint clay films on faces of peds and in pores; 25 percent gravel; moderately acid (pH 5.6); clear smooth boundary. (0 to 20 inches thick)
Bt3--30 to 65 inches; brown (10YR 5/3) gravelly clay loam, dark brown (10YR 3/3) moist; moderate medium angular blocky structure; hard, firm, sticky and plastic; common very fine and fine roots; common very fine and fine tubular pores; many distinct clay films on faces of peds and in pores; 20 percent gravel; moderately acid (pH 5.6); abrupt smooth boundary. (10 to 40 inches thick)
2C--65 to 70 inches; yellowish brown (10YR 5/4) silty clay loam, dark yellowish brown (10YR 4/6) moist; massive; hard, firm, sticky and plastic; few very fine roots; few very fine tubular pores; moderately acid (pH 5.6).
TYPE LOCATION: Twin Falls County, Idaho; about 22 miles southwest of Rogerson, Idaho; in the southwest 1/4, northeast 1/4, northeast 1/4 of section 16, T.16 S., R.13 E.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 35 to 65 inches
Base saturation in upper 40 inches - 60 to 75 percent
Clay in control section (average) - 20 to 26 percent
Coarse fragments in control section - 20 to 35 percent
Clay in the argillic horizon - 18 to 30 percent
Depth to welded tuff or ash - 60 inches or more
Average annual soil temperature - 37 to 43 degrees F.
Average summer soil temperature - 45 to 55 degrees F.
A horizon
Value - 3 or 4 dry, 2 or 3 dry
Chroma - 1 through 3 dry or moist
Reaction (pH) - slightly or moderately acid
Bt1 and Bt2 horizons
Value - 3 through 6 dry, 2 through 4 moist
Chroma - 1 through 4 dry or moist
Texture - GR-L, CB-L, or GR-CL
Rock fragments - 20 to 35 percent gravel, 0 to 10 percent cobbles Reaction (pH) - slightly or moderately acid
Bt3 horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Texture - GR-CL or CB-L
Rock fragments - 15 to 35 percent gravel, 0 to 15 percent cobbles
COMPETING SERIES: These are the Bachus, Benteen, Cambern, Clayburn, Crystalbutte, Davtone, DeCross, Demast, Dranyon, Echemoor, Gordo, Hagenbarth, Harmehl, Millerlake, Senchert, Southmount (T), Squawval, Stubbs, Thulepah, Vadnais and Winu series. Bachus, Benteen, Cambern, Harmehl, Senchert, Squawval, Vadnais, and Winu soils are 20 to 40 inches deep to bedrock. Crystalbutte and Dranyon soils have mollic epipedons that are less than 35 inches thick. Clayburn, Hagenbarth, and Southmount soils have less than 20 percent coarse fragments in the control section. Davtone and Gordo soils have hues of 5YR, or redder, in the Bt2 horizon. DeCross and Millerlake soils have Bk horizons. Demast soils are greater than 20 inches to the Bt horizon. Echemoor and Stubbs soils are 20 to 40 inches deep to a paralithic contact. Thulepah soils have a mollic epipedon that is 16 to 22 inches thick and have an average annual summer soil temperature that is 56 to 59 degrees F.
GEOGRAPHIC SETTING: Dehana soils are on mountain sideslopes and breaks. The slope ranges from 2 to 75 percent. The soils formed in slope alluvium and colluvium from welded rhyolitic tuff, latite, and volcanic ash. Elevations are 5,200 to 7,700 feet. The average annual precipitation ranges from 18 to 25 inches. The average annual temperature is 36 to 42 degrees F. The frost-free season is 20 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amboat, Brose, Eep, Hogmalat, Keman, Mug, Rutherford, and Kavon soils. Amboat, Keman, and Kavon soils are skeletal. Brose and Hogmalat soils are shallow to bedrock and occur on ridgetops and summit shoulders. Eep soils occur on the same landscape, but on drier exposures and are loamy-skeletal. Mug and Rutherford soils are moderately deep to bedrock and occur on terraces and summit shoulders.
DRAINAGE AND PERMEABILITY: Well drained, slow through rapid runoff; moderately slow permeability.
USE AND VEGETATION: Dehana soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is quaking aspen, common chokecherry, mountain big sagebrush, big bluegrass, Columbia needlegrass, mountain brome, and Idaho fescue.
DISTRIBUTION AND EXTENT: Dehana soils are of small extent in south central and southwestern Idaho.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Twin Falls County, Idaho, 1992.
REMARKS: Clay percent by hydrometer: 0-6 inches-20 percent; 6-15 inches-24 percent; 15-30 inches-26 percent; Base saturation: 0-6 inches-73 percent; 6-15 inches-63 percent; 15-30 inches-65 percent; 30-65 inches-61 percent; 65-70 inches-60 percent.
Diagnostic horizons and features recognized in this pedon:
Mollic epipedon (pachic) - from the surface to a depth of 65 inches (A, Bt1, Bt2, and Bt3 horizons).
Argillic horizon - from a depth of 6 to 65 inches (Bt1, Bt2, and Bt3 horizons).