LOCATION CHEDEHAP ID+NV WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Haplocambids
TYPICAL PEDON: Chedehap sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; weak very thin platy structure parting to very weak very fine granular; soft, very friable; many very fine and fine roots; many very fine interstitial pores; about 5 percent dark grains; about 2 percent fine gravel; slightly alkaline (pH 7.4); clear smooth boundary. (3 to 6 inches thick)
Bw1--4 to 14 inches; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable; common very fine and fine roots; many very fine tubular pores; about 5 percent dark grains; about 3 percent fine gravel; slightly alkaline (pH 7.5); gradual wavy boundary. (7 to 15 inches thick)
Bw2--14 to 17 inches; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable; few very fine and fine roots; common very fine tubular pores; about 2 percent fine gravel; common hard nodules and cicada krotovinas; slightly effervescent; moderately alkaline (pH 7.9); clear smooth boundary. (Combined thickness of the Bw horizon is 7 to 25 inches)
Bk1--17 to 22 inches; light gray (10YR 7/2) sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable; many fine roots; common very fine tubular pores; about 3 percent fine gravel; common hard nodules and cicada krotovinas; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (4 to 15 inches thick)
Bk2--22 to 29 inches; light gray (10YR 7/2) coarse sandy loam, grayish brown (10YR 5/2) moist; massive; slightly hard, very friable; many fine roots; common very fine tubular pores; about 5 percent fine gravel; strongly effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (0 to 15 inches thick)
2Bk3--29 to 35 inches; light gray (10YR 7/2) loamy coarse sand, grayish brown (10YR 5/2) moist; massive; slightly hard, very friable; common very fine tubular pores; about 8 percent gravel; strongly effervescent; strongly alkaline (pH 9.0); clear wavy boundary. (0 to 20 inches thick)
2Bk4--35 to 54 inches; light brownish gray (10YR 6/2) coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose; many very fine interstitial pores; about 6 percent fine gravel; strongly effervescent; very strongly alkaline (pH 9.1).
TYPE LOCATION: Power County, Idaho; 1,500 feet east of north-south El Paso Gas Co. compressor road, 5,400 feet south-southeast of intersection of this road with Highway 30W; SE1/4 NW1/4 section. 35, T.6S., R.33E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 53 degrees F. in Idaho and 50 to 56 degrees F. in Washington. Depth to loose sand and gravel - 25 to 40 inches. Average clay content in the control section - less than 18 percent. Average coarse fragments in the control section - 0 to 15 percent
A horizon Hue - 2.5Y or 10YR. Value - 5 through 7 dry, 3 through 5 moist. Chroma - 2 or 3 dry or moist. Reaction - neutral or mildly alkaline
Bw horizon Hue - 2.5Y or 10YR. Value of 5 or 6 dry, 3 or 4 dry or moist. Chroma - 2 through 4 dry or moist. Texture - FSL, SL, COSL. Reaction - neutral through moderately alkaline
Bk horizon Hue - 2.5Y or 10YR. Value - 5, 6 or 7 dry, 4 or 5 moist. Chroma - 2 or 3 dry or moist. Texture - SL, COSL, FSL, LFS. Calcium carbonate equivalent - 5 to 15 percent. Reaction - mildly alkaline or moderately alkaline.
2Bk horizon Hue - 2.5Y or 10YR. Value - 6 or 7 dry, 3 through 5 moist. Chroma - 2 or 3 dry or moist. Texture - LS, LCOS or COS. Rock fragment content - 0 to 35 percent. Reaction - moderately alkaline to very strongly alkaline
Some pedons have more than 15 percent exchangeable sodium below 40 inches.
COMPETING SERIES: These are the Adkins, Bijorja, Briabbit, Clems, Crestline, Deschutes, Haybourne, Irrigon, Kecko, McClenden, Prosser, Rebel, Royal, Sagehill, Scooteney, Sohappy, Vining, and Wiehl series. Adkins, Clems, Crestline, Kecko, McClenden, Prosser, Rebel, Royal, Sagehill, Scooteney, Sohappy and Wiehl soils do not have loose sand and gravel within 40 inches. Bijorja, Briabbit, and Irrigon soils are 20 to 40 inches to a paralithic contact. Deschutes and Vining are moderately deep to bedrock. Haybourne soils do not have a zone of calcium carbonate accumulation.
GEOGRAPHIC SETTING: Chedehap soils are on terraces and terrace escarpments at elevations of 2,200 to 5,000 feet in Idaho and 400 to 1,100 feet in Washington. Slopes range from 0 to about 20 percent. The soils formed in eolian material overlying alluvium and glacial outwash. The semiarid to arid climate has an average annual precipitation of 6 to 11 inches including that 1 to 3 feet of snowfall and an average freeze-free period of 100 to 160 days in Idaho and 150 to 210 days in Washington.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Declo, Feltham, Escalante, Paniogue, Timmerman, Tindahay and the competing Royal soils. Declo, Escalante, and Paniogue soils have calcic horizons. Feltham and Timmerman soils have loamy fine sand or loamy sand in the upper part of the 10- to 40-inch section. Tindahay soils lack a cambic horizon and have a sandy control section. These soils are on landscape positions similar to the Chedehap soil.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately rapid permeability in the upper part and very rapid permeability in the lower part.
USE AND VEGETATION: Most is irrigated for potatoes, small grains, hay, and pasture. Some is used for range. The natural vegetation is big sagebrush, cheatgrass, Sandberg bluegrass, wild mustard, bluebunch wheatgrass, needleandthread grass, phlox, western wheatgrass, Indian ricegrass, and rabbitbrush or bitterbrush.
DISTRIBUTION AND EXTENT: Southern Idaho, northern Nevada, and south central Washington. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Fort Hall Area, Idaho, 1973.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to 4 inches (A horizon)
Cambic horizon - the zone from 4 to 17 inches (Bw1 and Bw2 horizons)
Particle size control section - the zone from 10 to 40 inches (Part of the Bw1, Bw2, Bk1, Bk2, 2Bk3, and part of the 2Bk4 horizon. This soil is reclassified based on amendment 17 of Soil Taxonomy.