LOCATION BOCKSTON ID+UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Calcixerolls
TYPICAL PEDON: Bockston loam, grass and annual weeds. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 9 inches, brown (10YR 5/3) loam, very dark grayish brown (10YR 3/2) moist; strong medium granular structure; moderate thin platy structure in upper 4 inches; slightly hard, friable, sticky and slightly plastic; few very fine, fine and medium roots; many very fine, fine, medium and coarse tubular pores; slightly effervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (7 to 14 inches thick)
Bw1--9 to 15 inches, pale brown (10YR 6/3) silt loam, grayish brown (10YR 5/2) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few very fine fine and medium roots; many very fine and fine, common medium and coarse tubular pores; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (5 to 10 inches thick)
Bw2--15 to 21 inches, pale brown (10YR 6/3) silt loam, light brownish gray (10YR 6/2) moist; moderate medium platy structure parting to strong fine angular blocky; slightly hard, friable, moderately sticky and slightly plastic; few very fine and fine roots; many very fine and fine, few medium and coarse tubular pores; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 10 inches thick)
Bk1--21 to 28 inches, light gray (10YR 7/2) silt loam, light brownish gray (10YR 6/2) moist; moderate medium platy structure parting to moderate medium subangular blocky; slightly hard, friable, moderately sticky and slightly plastic; few very fine and fine roots; many very fine and fine, few medium and coarse tubular pores; many light gray (10YR 7/2) moist, lime veins and splotches; violently effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (6 to 12 inches thick)
2Bk2--28 to 38 inches, light brownish gray (10YR 6/2) fine sandy loam, brown (10YR 5/3) moist; massive; soft, very friable; nonsticky and nonplastic; few very fine and fine roots; many very fine and fine tubular pores; strongly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 15 inches thick)
3Bk3--38 to 43 inches, light brownish gray (10YR 6/2) extremely gravelly fine sandy loam, grayish brown (10YR 5/2) moist; massive; soft, very friable; nonsticky and nonplastic; few very fine and fine roots; many very fine and fine tubular pores; about 45 percent gravel and 15 percent cobbles; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 10 inches thick)
4Bk4--43 to 60 inches, light brownish gray (10YR 6/2) extremely gravelly loamy sand, grayish brown (10YR 5/2) moist; single grained; loose; nonsticky and nonplastic; few very fine and fine roots; 50 percent gravel and 20 percent cobbles; lime coats on underside of rock fragments; strongly effervescent; slightly alkaline (ph 7.8).
TYPE LOCATION: Jefferson County, Idaho; about 3 miles west, 2.5 miles south of Rigby; 530 feet south, 80 feet east from NW corner of sec. 34, T.4N., R.38E.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon - 7 to 14 inches
Depth to the calcic horizon - 14 to 22 inches
Depth to the extremely gravelly material - 30 to more than 60 inches
Average annual soil temperature - 42 to 46 degrees F.
Particle-size control section:
Clay content (weighted average, total) - 20 to 27 percent
Sand content - more than 15 percent coarser than very fine sand
Carbonate fre clay - 18 to 22 percent
A horizon:
Value - 2 or 3 moist, 4 or 5 dry
Chroma - 2 or 3 dry or moist
Organic matter content - 1.5 to 2.5 percent
Reaction - slightly or moderately alkaline
Bw horizon:
Value - 5 to 7 dry, 3 to 6 moist
Chroma - 2 or 3 dry or moist
Texture - SIL, L, GR-FSL
Rock fragment content - 0 to 25 percent
COMPETING SERIES: This is the Sanpitch series. Sanpitch soils lack B horizons and have 15 to 35 percent gravel in the control section.
GEOGRAPHIC SETTING: The soils are on stream terraces and fan terraces. Elevations range from 4,800 to 5600 feet. Slopes are 0 to 6 percent. These soils formed in mixed alluvium. The climate has an average frost-free season of 55 to 115 days. Precipitation is 8 to 13 inches including 1 to 3 feet of snowfall. The mean annual temperature is 41 to 43 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bannock, Hayeston, Heiseton, and Wardboro soils. Hayeston and Heiseton soils have a coarse-loamy control section, and Hayeston soils are 20 to 40 inches deep. Wardboro soils are 10 to 20 inches deep. Bannock soils contain less than 18 percent clay in the particle-size control section and are 20 to 40 inches deep to sand and gravel.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate in the upper part and moderately rapid to rapid in the lower part.
USE AND VEGETATION: Cultivated. Used mostly for irrigated hay, small grains, pasture and potatoes. The principal native plants are big sagebrush, bluebunch wheatgrass, Sandberg bluegrass and squirreltail.
DISTRIBUTION AND EXTENT: Jefferson County, Idaho; the series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County, Idaho, 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 9 inches (Ap horizon)
Cambic horizon - the zone from 9 to 21 inches (Bw1 and Bw2 horizons)
Calcic horizon - the zone from 21 to 28 inches (Bk1 horizon)
Particle-size control section - the zone from 10 to 40 inches (part of the Bw1, Bw2, Bk1, 2Bk2, and part of the 3Bk3 horizons)