LOCATION POCATELLO          ID
Established Series
Rev. RWW/CLM/GHL
03/1999

POCATELLO SERIES


The Pocatello series consists of very deep, well drained soils that formed in loess and silty alluvium derived from loess. Permeability is moderate. These soils are on foothills and terraces and have slopes of 0 to 60 percent. The average annual precipitation is about 10 inches and the average annual temperature is about 49 degrees F.

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Xeric Torriorthents

TYPICAL PEDON: Pocatello silt loam, crested wheatgrass. (Colors are for dry soil unless otherwise noted.)

A--0 to 4 inches; light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thin and very thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine vesicular pores; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 5 inches thick)

Bk1--4 to 8 inches; light brownish gray (10YR 6/1) silt loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots and few medium roots; many very fine tubular pores; effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (2 to 6 inches thick)

Bk2--8 to 13 inches; light brownish gray (10YR 6/2) pale brown (10YR 6/3) crushed silt loam, dark grayish brown (10YR 4/2) moist; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular pores; very few 1/2 inch hard cicada casts krotovinas; strongly effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (4 to 8 inches thick)

Bk3--13 to 18 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few medium roots; many very fine tubular pores; strongly effervescent; very few 1/2 inch hard cicada casts; strongly alkaline (pH 8.5); clear wavy boundary. (3 to 8 inches thick)

Bk4--18 to 38 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine tubular pores; hard or very hard 1/2 to 1 inch cicada casts that slake in water occupy 15 percent in upper part to 8 percent in lower part; strongly effervescent, common fine veins and small splotches of lime; strongly alkaline (pH 9.0); gradual wavy boundary. (12 to 25 inches thick)

Ck1--38 to 58 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine tubular pores; few hard cicada casts; strongly effervescent, very few fine lime veins; very strongly alkaline (pH 9.1); gradual wavy boundary. (5 to 25 inches thick)

Ck2--58 to 70 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine tubular pores; strongly effervescent, very few lime veins; strongly alkaline (pH 9.0).

TYPE LOCATION: Power County, Idaho; about 1/2 mile northwest of the compressor station, northeast 1/4, southwest 1/4 corner of sec. 10, T. 7 S., R. 32 E.

RANGE IN CHARACTERISTICS:

The mean annual soil temperature: 47 to 53 degrees F. Particle-size control section: 5 to 15 percent clay and
less than 5 percent particles coarser than very fine sand.

A horizon: color value: dry - 5 through 7; moist - 3 through 5; chroma, dry or moist 2 or 3; reaction - neutral through moderately alkaline; effervescence none or strong. Calcium carbonate is 0 to 10 percent.

Bk1 horizon: color chroma: dry or moist 1 through 3; reaction - neutral through moderately alkaline; effervescence - slight or strong. Calcium carbonate is 5 to 10 percent.

Bk2, Bk3 or Bk4 horizon: color value: dry - 6 or 7, moist - 4 or 5; chroma - dry or moist 2 or 3 Krotovinas (cicada) 5 to 15 percent hard or very hard; reaction - moderately alkaline through strongly alkaline; salinity - nonsaline or slightly saline. Calcium carbonate is 5 to 15 percent.

Ck horizon: color value: dry - 6 or 7, moist - 4 or 5; chroma - dry or moist 2 through 4; texture - silt loam or silt; reaction - slightly alkaline through very strongly alkaline; salinity - moderately saline or strongly saline in some pedons. Calcium carbonate is 5 to 15 percent.

COMPETING SERIES: These are the Kennewick, Linoyer, Ritzcal, and Wheeler series. Kennewick soils have hard firm laminated silt loam layers above a depth of 40 inches. Wheeler soils have over 15 percent calcium carbonate. Ritzcal soils have very hard and very firm consistance in the subsoil and are strongly effervescent at the surface.
Linoyer soils lack segregated carbonates.

GEOGRAPHIC SETTING: Pocatello soils are on foothills and terraces at elevations of 3,000 to 5,200 feet. Slopes range from 0 to 60 percent. These soils formed in loess and silty alluvium derived from loess. The semi-arid climate has an mean annual precipitation range of 8 to 12 inches. The mean annual temperature is 45 to 51 degrees F. Frost-free season is 100 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bahem, Kucera, McDole, Neeley, Portneuf, and the competing Wheeler series. Bahem and Portneuf soils have calcic horizons. Kucera, McDole, and Neeley soils have mollic epipedons. Bahem and Portneuf soils are on older land forms. Kucera and Neeley soils are on north and east-facing slopes. McDole soils are in drainageways. Wheeler soils are on eroded south and west-facing slopes.

DRAINAGE AND PERMEABILITY: Well drained; runoff is slow to very rapid; permeability is moderate.

USE AND VEGETATION: This Pocatello soil is used mainly for rangeland. Some areas are used for irrigated and nonirrigated crops. The potential natural vegetation is Wyoming big sagebrush and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Southeastern, Idaho. This series is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Power County, Idaho, 1973.

REMARKS: Diagnostic horizons and other features:

Ochric epipedon


National Cooperative Soil Survey
U.S.A.