LOCATION BUNCELVOIR IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Haplargids
TYPICAL PEDON: Buncelvoir loam -- on a slightly concave slope of 2 percent, in seeded rangeland at 4,890 feet elevation. (When described on June 17, 1980, the soil was dry throughout. Colors are for air-dry soils unless otherwise stated.)
A1--0 to 4 inches; light gray (10YR 7/2) loam, brown (10YR 4/3) moist; weak fine platy structure parting to moderate fine granular; soft, very friable; common very fine and fine, few medium roots; common very fine and fine vesicular pores; 10 percent gravel; slightly alkaline (pH 7.5); clear smooth boundary. (2 to 5 inches thick)
AB--4 to 7 inches; light gray (10YR 7/2) loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine and fine tubular pores; 10 percent gravel; slightly alkaline (pH 7.7); clear smooth boundary. (0 to 4 inches thick)
Bt--7 to 15 inches; light yellowish brown (10YR 6/4) silty clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure parting to strong fine angular blocky; hard, firm, sticky and very plastic; common very fine and fine, few medium roots; common very fine tubular pores; continuous distinct clay films on faces of peds; 10 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (7 to 14 inches thick)
Btk--15 to 19 inches; very pale brown (10YR 7/4) clay loam, yellowish brown (10YR 5/6) moist; moderate fine and medium angular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; few very fine tubular pores; common distinct clay films on faces of peds; 10 percent gravel; strongly effervescent; moderately alkaline (pH 8.3); clear smooth boundary. (3 to 7 inches thick)
Bkq1--19 to 26 inches; very pale brown (10YR 7/3) gravelly sandy loam, light yellowish brown (10YR 6/4) moist; weak medium subangular blocky structure; slightly hard, friable; few very fine and fine roots; few very fine tubular, few fine vesicular pores; 15 percent gravel; 10 percent durinodes; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (7 to 20 inches thick)
Bkq2--26 to 60 inches; very pale brown (10YR 7/3) gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; few very fine roots; 30 percent gravel; 10 percent durinodes; violently effervescent; strongly alkaline (pH 8.5).
TYPE LOCATION: Owyhee County, Idaho; about 5 1/2 miles west and 9 1/2 miles north of Grasmere; 2700 feet west and 500 feet south of the northeast corner of section 33, T.10 S., R.4 E.; 43 degrees, 01 minutes, 20 seconds North Latitude and 115 degrees, 54 minutes, 57 seconds West Longitude.
RANGE IN CHARACTERISTICS:
Depth to calcium carbonates - 10 to 18 inches
Depth to base of argillic - 13 to 24 inches
Average annual soil temperature - 47 to 49 degrees F.
A horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 2 through 4 dry or moist
Rock fragments - 0 to 10 percent
Reaction (pH) - neutral or slightly alkaline
Bt horizon
Value - 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - SICL, C, or CL
Clay content - 35 to 45 percent
Rock fragments - 0 to 10 percent
Btk horizon
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 4 through 6 dry or moist
Texture - SICL or CL
Clay content - 30 to 40 percent
Rock fragments - 0 to 10 percent
Calcium carbonate equivalent - 1 to 10 percent
Bkq horizon
Value - 6 or 7 dry, 4 through 7 moist
Chroma - 3 through 6 dry or moist
Texture - FSL, GR-FSL, or GR-SL
Rock fragments - 5 to 30 percent
Durinodes - 0 to 20 percent
Calcium carbonate equivalent - 3 to 15 percent
Reaction (pH) - moderately or strongly alkaline
COMPETING SERIES: These are the Diaz, Farmell, Glasgow, Lanktree, Linkletter, Oppio, Risley, Schamp, and Trunk series. The Diaz, Glasgow, Oppio, Risley, and Trunk soils are less than 40 inches deep to lithic or paralithic contact. Farmell soils are greater than 24 inches to secondary carbonates. Lanktree soils have "E" horizons. Linkletter soils have a duripan 40 to 60 inches deep. Schamp soils have argillic horizons 24 to 32 inches thick and solum depth of 27 to 36 inches.
GEOGRAPHIC SETTING: Buncelvoir soils are nearly level to gently sloping on tablelands and calderas at elevations of 4800 to 5400 feet. Slopes range from 1 to 6 percent. These soils formed in alluvium and loess from basalt and volcanic ash. The climate is cool and moist in winter and hot and dry in summer. Average annual precipitation ranges from 8 to 13 inches. Average annual temperature ranges from 45 to 47 degrees F. Frost-free period is 90 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arbidge, Bruncan, Chilcott, and Hardtrigger series. Arbidge, Bruncan, and Chilcott have duripans. Arbidge, Bruncan, and Hardtrigger soils have fine-loamy argillic horizons. These soils are on similar landscape positions.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: Buncelvoir soils are used mainly for rangeland and wildlife habitat. The dominant natural vegetation is Wyoming big sagebrush, bluebunch wheatgrass, Thurber needlegrass, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Southwestern Idaho. Buncelvoir soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Owyhee County Area, Idaho, 1992.
REMARKS: This revision (6/95) changes the classification from Xerollic Haplargids to Xeric Haplargids according to the 1994 edition of Keys to Soil Taxonomy. The remainder of the OSD has not been updated since 8/93.
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - 0 to 7 inches (A and AB horizons)
Argillic horizon and particle-size control section - 7 to 19 inches (Bt and Btk horizons)