LOCATION DIAWELL IDEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Haploxeralfic Argidurids
TYPICAL PEDON: Diawell gravelly sandy clay loam -- on a west-facing slope of 16 percent, in seeded rangeland at 3,500 feet elevation. (When described on June 4, 1986, the soil was dry throughout. Colors are for air-dry soil unless otherwise stated.)
A--0 to 3 inches; pale brown (10YR 6/3) gravelly sandy clay loam, brown (10YR 4/3) moist; moderate fine granular structure; slightly hard, very friable, sticky and plastic; common very fine and fine, few medium roots; common very fine and fine vesicular pores; 25 percent gravel; neutral (pH 7.0); clear smooth boundary. (3 to 4 inches thick)
AB--3 to 6 inches; pale brown (10YR 6/3) gravelly sandy clay loam, brown (10YR 4/3) moist; moderate medium granular structure; slightly hard, friable, sticky and plastic; common very fine and fine, few medium roots; common very fine and fine vesicular pores; 30 percent gravel; neutral (pH 7.1); clear smooth boundary. (0 to 5 inches thick)
Bt--6 to 11 inches; light yellowish brown (10YR 6/4) gravelly sandy clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; common very fine and fine, few medium roots; common very fine and fine tubular pores; many faint clay films on faces of peds and in pores; 30 percent gravel; neutral (pH 7.3); clear smooth boundary. (4 to 8 inches thick)
Bkq--11 to 20 inches; very pale brown (10YR 7/3) gravelly fine sandy loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; soft, very friable; few very fine, fine and medium roots; few very fine tubular pores; 20 percent durinodes; 20 percent gravel; violent effervescence; slightly alkaline (pH 7.7); abrupt smooth boundary. (4 to 10 inches thick)
Bkqm--20 to 22 inches; very pale brown (10YR 7/4) strongly cemented continuous duripan, yellowish brown (10YR 5/4) moist; massive; very hard, very firm; 35 percent gravel; violent effervescence; clear smooth boundary. (2 to 5 inches thick)
2Bk1--22 to 30 inches; light yellowish brown (10YR 6/4) gravelly sandy loam, yellowish brown (10YR 5/4) moist; massive; soft, very friable; 15 percent gravel; strong effervescence; moderately alkaline (pH 8.0); gradual smooth boundary. (8 to 40 inches thick)
2Bk2--30 to 50 inches; light yellowish brown (10YR 6/4) gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable; 15 percent gravel; strong effervescence; moderately alkaline (pH 8.1); gradual smooth boundary. (0 to 20 inches thick)
3Ck--50 to 60 inches; light yellowish brown (10YR 6/4) very gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable; 50 percent gravel; slight effervescence; slightly alkaline (pH 7.7).
TYPE LOCATION: Owyhee County, Idaho; about 5 miles south of Murphy; 800 feet west and 150 feet north of the southeast corner of section 21, T.3 S., R.2 W.; 43 degrees, 08 minutes, 26 seconds North Latitude and 116 degrees, 34 minutes, 24 seconds West Longitude.
RANGE IN CHARACTERISTICS:
Depth to base of argillic and top of calcic - 10 to 14 inches
Depth to duripan - 14 to 20 inches
Particle-size control section - 18 to 30 percent clay; 15 to 35 percent coarse fragments
Average annual soil temperature - 51 to 53 degrees F.
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Coarse fragments - 15 to 25 percent
Bt horizon
Value - 5 or 6 dry
Chroma - 3 or 4 dry or moist
Texture - GR-SCL, GR-CL, or CL
Clay content - 27 to 35 percent
Coarse fragments - 5 to 35 percent
Reaction (pH) - neutral or slightly alkaline
Bkq horizon
Value - 6 or 7 dry, 5 or 6 moist
Chroma - 3 or 4 dry or moist
Texture - GR-FSL or GR-SL
Clay content - 10 to 18 percent
Coarse fragments - 15 to 35 percent
Reaction (pH) - neutral or slightly alkaline
Calcium carbonate equivalent - 15 to 25 percent
Bkqm horizon
Value - 6 or 7 dry, 5 or 6 moist
Chroma - 3 or 4 dry or moist
Coarse fragments - 15 to 60 percent
Bk horizon
Value - 6 or 7 dry, 4 through 6 moist
Chroma - 3 or 4 dry or moist
Texture - stratified; GRV-LS and GR-SL
Clay content - 4 to 10 percent
Coarse fragments - 15 to 50 percent
Reaction (pH) - slightly or moderately alkaline
Calcium carbonate equivalent - 10 to 25 percent
COMPETING SERIES: These are the Mickey, Minu, Muni, and Zadvar series. Mickey soils have duripans 15 to 25 inches thick and lack carbonates above the duripan. Minu soils are intermittently moist in summer due to summer convection storms and are calcareous in the lower part of the argillic horizon. Muni soils have a 10 to 36 inch thick duripan and average less than 15 percent rock fragments in the control section. Zadvar soils are 10 to 14 inches deep to a duripan. In addition, Mickey and Zadvar soils are moist for 10 to 20 days during the summer.
GEOGRAPHIC SETTING: Diawell soils are nearly level to rolling fan on dissected fan piedmonts at elevations of 3,200 to 4,200 feet. Slopes range from 2 to 20 percent. These soils formed in mixed alluvium from intermediate intrusive rocks and vitric tuff. The climate is cool and moist in the winter and hot and dry in the summer. Average annual precipitation ranges from 8 to 11 inches. Average annual temperature ranges from 48 to 51 degrees F. Frost-free period is 110 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hardtrigger and McKeeth series. Hardtrigger soils lack duripans and are on similar landscape positions. McKeeth soils lack a continuously cemented duripan and are on nearly level fan summits.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Diawell soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is Wyoming big sagebrush, Thurber needlegrass, Sandberg bluegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Southwestern Idaho. Diawell soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Owyhee County Area, Idaho, 1992.
REMARKS: This revision (6/95) changes the classification from Haploxerollic Durargids to Haploxeralfic Argidurids according to the 1994 edition of Keys to Soil Taxonomy. The remainder of the OSD has not been updated since 6/93.
Diagnostic horizons and other features recognized in this pedon:
Ochric epipedon - zone 0 to 6 inches (A and AB horizons)
Argillic horizon - zone 6 to 11 inches (Bt horizon)
Calcic horizon - zone 11 to 20 inches (Bkq horizon)
Duripan (strongly cemented) - zone 20 to 22 inches (Bkqm horizon)
Particle-size control section - zone 6 to 20 inches (Bt and Bkq horizons)