LOCATION SULOAF ID+WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ultic Argixerolls
TYPICAL PEDON: Suloaf silt loam, woodland. (Colors are for dry soil unless otherwise noted.)
0i--0 to 1 inch; fresh and partially decomposed needles and twigs.
A1--1 to 4 inches; brown (7.5YR 4/3) silt loam, dark brown (7.5YR 3/2) moist; weak very very fine and fine subangular blocky and weak fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine and many medium to coarse roots; common very fine and fine interstitial pores; neutral (pH 6.6); gradual wavy boundary. (10 to 20 inches thick)
A2--4 to 18 inches; brown (7.5YR 4/3) silt loam, dark brown (7.5YR 3/2) moist; weak very fine and fine subangular blocky and weak fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine and many medium to coarse roots; common very fine and fine interstitial pores; neutral (pH 6.6); gradual wavy boundary. (10 to 20 inches thick)
Bt1--18 to 29 inches; light yellowish brown (10YR 6/4) gravelly silt loam, brown (7.5YR 4/4) moist; moderate very fine and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine and fine and many medium roots; common very fine and fine tubular pores; common distinct clay films on peds and in pores; slightly acid (pH 6.4); gradual smooth boundary. (5 to 20 inches thick)
Bt2--29 to 42 inches; light brown (7.5YR 6/4) gravelly silt loam, brown (7.5YR 4/4) moist; moderate very fine and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine and medium roots; common fine tubular pores; common faint clay films on peds and in pores; slightly acid (pH 6.4); gradual smooth boundary. (5 to 20 inches thick)
BC--42 to 55 inches; reddish yellow (7.5YR 6/6) gravelly sandy loam, strong brown (7.5YR 5/6) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; slightly acid (pH 6.4); clear smooth boundary. (5 to 15 inches thick)
R--55 inches; basalt.
TYPE LOCATION: Idaho County, Idaho; about 7 miles southwest of White Bird; about 2,640 feet east and 230 feet north of the southwest corner of section 18, T.27N., R.1E.
RANGE IN CHARACTERISTICS: Depth to bedrock and thickness of the solum are more than 40 inches. The soil is usually moist but is dry between depths of 4 and 12 inches for 45 to 70 consecutive days in late summer and early fall. The mean annual soil temperature ranges from 43 to 47 degrees F. The mean summer soil temperature ranges from 59 to 63 degrees F. Rock fragments are present in the Bt and where present, BC horizons of some pedons and range from 0 to 35 percent by volume in the B horizons. The solum has hue of 10YR or 7.5YR. The mollic epipedon is 12 to 20 inches thick. Depth to an argillic horizon is 8 to 20 inches. Base saturation in parts of the upper 30 inches is less than 75 percent and is 50 to 75 percent in the mollic epipedon.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3.
The Bt horizon has value of 4 through 6 dry, 4 through 5 moist, and chroma of 3 or 4. It has 25 to 35 percent clay and 15 to 30 percent sand coarser than very fine sand.
Some pedons do not have a BC horizon above the bedrock. The BC horizon is usually clay loam, cobbly clay loam, or gravelly sandy loam and its structure is blocky or the soil is massive.
COMPETING SERIES: These are the Carmack, Elkcreek, Johnson, Middlefork, Mojo, Molyneux, Muldoon, Simonton, Skelter and Trojan series. Carmack, Middlefork, Molyneux, Simonton, and Skelter soils are very deep. Elkcreek and Mojo soils are moderately deep to a lithic contact. Johnson soils have 30 to 60 percent fine sand or coarser and have more quartz grains and mica flakes. Muldoon soils are deep to a duripan. Trojan soils are usually dry between depths of 10 and 20 inches for more than 100 days.
GEOGRAPHIC SETTING: Suloaf soils are on high plateaus, mountains and northerly aspects of canyons and have gradients of 3 to 90 percent. They formed in loess and residuum weathered from Columbia River basalt or andesite or greenstone of the Seven Devil volcanics. Elevation ranges from 2,500 to 5,000 feet. The mean annual precipitation is 24 to 28 inches. The mean annual temperature is 41 to 45 degrees F. The frost free season period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bluesprin, De Masters, Klickson, Riggens, Telcher and Umptmor soils. Bluesprin, Riggins and Klickson soils have more than 35 percent rock fragments in the control section. Telcher soils have an ochric epipedon and Uptmor soils are clayey.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: The soils are used for hay, pasture, woodland and recreation. The natural vegetation is mainly Douglas fir, ponderosa pine, ninebark, oceanspray and snowberry.
DISTRIBUTION AND EXTENT: Northern Idaho and possibly eastern Oregon and south central and southeastern Washington. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Idaho County, Idaho, 1976.