LOCATION DECLO ID+UTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Haplocalcids
TYPICAL PEDON: Declo loam - cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine and fine tubular pores; moderately calcareous; moderately alkaline (pH 8.1); abrupt smooth boundary. (0 to 10 inches thick)
Bw--7 to 10 inches; pale brown (10YR 6/3) loam, grayish brown (10YR 5/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine and fine tubular pores; moderately calcareous; mildly alkaline (pH 7.8); clear wavy boundary. (0 to 6 inches thick)
Bk1--10 to 14 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; moderate medium platy structure parting to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine and fine tubular pores; strongly calcareous; violently effervescent lime segregated into common fine irregularly shaped filaments and soft masses; moderately alkaline (pH 7.9); gradual wavy boundary. (0 to 6 inches thick)
Bk2--14 to 25 inches; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine and fine tubular pores; common hard nodules of soil or cicada krotovinas; strongly calcareous; violently effervescent lime segregated into common fine irregularly shaped filaments and soft masses; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 20 inches thick)
Bk3--25 to 44 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine and fine tubular pores; few sand pockets or lenses; strongly calcareous; violently effervescent lime segregated into common fine irregularly shaped filaments and soft masses; moderately alkaline (pH 8.0); gradual smooth boundary. (0 to 20 inches thick)
Bk4--44 to 64 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; lenses 1/2 to 1 inch thick that have brownish yellow (10YR 6/6) staining and mottles that are dark yellowish brown (10YR 4/4) moist (mottles increase with depth); weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine and fine tubular pores; moderately calcareous; violently effervescent lime segregated into common fine irregularly shaped filaments and soft masses; moderately alkaline (pH 8.0).
TYPE LOCATION: Bingham County, Idaho; southeast corner of Aberdeen; 100 feet north and 1,620 feet east of the southwest corner of the SE1/4 sec. 33, T.6S., R.31E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 55 degrees F.
Depth to calcic horizon - 3 to 18 inches
Laminated sediments are present in some pedons below depths of 25 to 40 inches
Particle size control section
Texture - SIL, L, or VFSL
Percent clay - 8 to 18
A horizon
Value - 5 through 7 dry, 3 through 5 moist
Chroma - 2 or 3
Effervescence - none through moderate
Reaction - neutral through moderately alkaline
Bk horizons
Hue - 10YR or 2.5Y
Value - 6 through 8 dry, 2 through 6 moist
Chroma - 1 through 3
Texture - L, SIL, VFSL, SL, GR-L (the coarser textures occur in the lower part of the profile)
Coarse fragments - 0 to 15 percent in the control section
Nodules or krotovina - 3 to 15 percent
Calcium carbonate equivalent - 15 to 30 percent (some pedons have layers that contain up to 50 percent)
Exchangeable sodium - in some pedons - 15 to 30 percent
Reaction - moderately alkaline or strongly alkaline
COMPETING SERIES: These are the Bertelson, Eccles, Escalante, Fione, Palisade, Somsen, and Strevell series. Bertleson, Eccles, and Escalante soils have dominantly moderately coarse textured control sections. Eccles and Fione soils are moderately rapidly permeable and have cambic horizons. Palisade soils lack coarse fragments and/or laminations in the substratum. Somsen soils have bedrock at depths of 20 to 40 inches. Strevell soils have a skeletal discontinuity at depths of 25 to 40 inches.
GEOGRAPHIC SETTING: Declo soils are on terraces, terrace sideslopes, and valley floors. Slopes range from 0 to 20 percent, and are dominantly less than 4 percent. They formed in alluvium or lacustrine material that has been reworked by wind and water. Elevation ranges from 2,500 to 5,600 feet. Some areas are locally influenced by loess or silty alluvium from loess. The average annual precipitation ranges from 8 to 12 inches, including about 2 feet of snow. The average annual air temperature ranges from 45 to 53 degrees F. The frost free season is about 95 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Escalante and Strevell (T) soils and the Bahem, Banbury, Darkbull, Fingal, Owsel, Paniogue, Portino, Portneuf, and Trevino soils. Bahem and Portneuf soils have a coarse silty control section. Darkbull and Paniogue soils have discontinuities to sand and gravel above 40 inches. Fingal soils have a mollic epipedon and mottles due to wetness above a depth of 40 inches. Owsel soils have an argillic horizon. Portino, Banbury, and Trevino soils have bedrock at 20 to 40 inches and 10 to 20 inches respectively. Portneuf soils have a layer that contains greater than 20 percent durinodes or have a layer that is firm and brittle within the control section. Bahem, Darkbull, Escalante, Fingal, Paniogue, Portneuf, and Strevell soils are on terraces. Portino and Trevino soils are on basalt plains.
DRAINAGE AND PERMEABILITY: Well drained, slow or medium runoff; moderate permeability.
USE AND VEGETATION: Used primarily for irrigated cropland. The potential natural vegetation is mainly Wyoming big sagebrush, bluebunch wheatgrass, Sandberg bluegrass, Thurber needlegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Southern Idaho and northern Utah. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Minidoka County, Idaho, 1923.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 7 inches (Ap horizon).
Calcic horizon - the zone from 10 to 44 inches (Bk1, Bk2, and Bk3 horizons).
Particle-size control section - the zone from 10 to 40 inches.