LOCATION BUKO IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Durinodic Xeric Haplocalcids
TYPICAL PEDON: Buko silt loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 7 inches; brown (10YR 5/3) silt loam, pale brown (10YR 6/3) rubbed, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; few fine pores; moderately alkaline (pH 8.0); gradual wavy boundary. (3 to 7 inches thick)
B2--7 to 12 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; common fine pores; moderately alkaline (pH 8.1); clear wavy boundary. (5 to 13 inches thick)
C1ca--12 to 20 inches; very pale brown (10YR 7/3) loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine pores; pockets of root mats; 50 percent hard firm cicada nodules; moderately calcareous; moderately alkaline (pH 8.4); clear smooth boundary. (6 to 11 inches thick)
C2casi--20 to 28 inches; very pale brown (10YR 8/3) loam, yellowish brown (10YR 5/4) moist; massive; hard, very firm, slightly sticky and slightly plastic; few very fine and fine roots; few very fine pores; weakly cemented (brittle); strongly calcareous; moderately alkaline (pH 8.4); clear irregular boundary. (6 to 8 inches thick)
IIC3ca--28 to 44 inches; very pale brown (10YR 7/3) very gravelly loamy sand, yellowish brown (10YR 5/4) moist; single grained; loose; few very fine roots; 55 percent gravel; moderately calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Cassia County, Idaho; about 13 miles south of Burley, 0.75 mile east of pole line road; 100 feet north and 1,700 feet east of SW corner of sec. 29, T.12S., R.23E.
RANGE IN CHARACTERISTICS: Depth to loose sand and gravel is 20 to 36 inches. The sad and gravel consists of stratified layers of sands and loamy sands, with gravel content ranging from 20 to 70 percent but averaging 35 to 60 percent. Depth to secondary carbonates is 11 to 17 inches. Mean annual soil temperature is about 49 degrees to 53 degrees F.
The A horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3. Organic matter is estimated to be 1.5 to 3 percent in the A horizon, and decreases regularly with increasing depth.
The B2 horizon has chroma of 3 or 4. It is usually clay loam or silty clay loam but includes loam or silt loam with 18 to 35 percent clay and 40 to 60 percent silt.
The Cca horizon contains 20 to 50 percent nodules and/or durinodes. A part of the Cca horizon at least 6 inches thick, is weakly cemented and contains 15 to 25 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Connel (T), Ephrata, Neppel, and Paniogue series. Connel soils contain less than 18 percent clay in the control section, and have less than 5 percent calcium carbonate equivalent in the Cca horizon. Ephrata and Paniogue soils lack weakly cemented horizons.
GEOGRAPHIC SETTING: Buko soils are on alluvial terraces and have slope gradients of 0 to 7 percent. They formed in material weathered from calcareous mixed alluvium. Elevations are 4,100 to 4,600 feet. The climate is semiarid with dry summers and moist winters. Mean annual precipitation is 8 to 11 inches. Mean annual temperature is 47 degrees to 51 degrees F. Frost-free season is about 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Drax and Declo soils. Drax soils have mollic epipedons, and are deeper than 40 inches to sand and gravel. Declo soils have calcic horizons, have lime extending to the surface and are over 40 inches deep to sand and gravel.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: Used mainly for irrigated cropland. Crops are potatoes, sugar beets and alfalfa hay. Vegetation is big sagebrush, bluebunch wheatgrass, Sandberg bluegrass, and bottlebrush squirrel tail.
DISTRIBUTION AND EXTENT: South-central Idaho. These soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cassia County, Idaho, 1975.