LOCATION EDDS WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy, glassy over isotic Humic Xeric Vitricryands
TYPICAL PEDON: Edds ashy loam - grass, shrub. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; dark gray (10YR 4/1) ashy loam, black (10YR 2/1) moist; weak fine and medium granular and medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many fine roots; 15 percent fine gravel; slightly acid (pH 6.1); abrupt smooth boundary. (4 to 6 inches thick)
AB--6 to 12 inches; grayish brown (10YR 5/2) ashy loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many fine roots; 15 percent fine gravel; slightly acid (pH 6.1); clear wavy boundary. (6 to 9 inches thick)
Bw1--12 to 17 inches; very pale brown (10YR 7/3) ashy loam, brown (10YR 4/3) moist; moderate medium and fine subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; many fine roots; 15 percent fine gravel; moderately acid (pH 5.8); clear wavy boundary. (5 to 7 inches thick)
Bw2--17 to 24 inches; light yellowish brown (10YR 6/4) ashy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse angular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; many fine roots; many tubular pores; thin patchy clay films in pores, and clay bridges of sand grains; 5 percent gravel; slightly acid (pH 6.3); clear wavy boundary. (6 to 9 inches thick)
2C1--24 to 28 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; single grained; loose, friable, slightly sticky, nonplastic; many fine roots; slightly acid (pH 6.2); clear wavy boundary. (3 to 6 inches thick)
3C2--28 to 40 inches; light gray (10YR 7/2) gravelly loamy coarse sand, grayish brown (10YR 5/2) moist; massive; hard, firm, nonsticky, nonplastic; many tubular pores; many clean sand grains; 25 percent pebbles; slightly acid (pH 6.2); gradual irregular boundary. (10 to 15 inches thick)
4C3--40 inches; grayish brown (10YR 5/2) loam, dark grayish brown (10YR 4/2) moist; strong medium platy structure; hard, very firm, moderately sticky and moderately plastic; sand grains bridged with clay; slightly acid (pH 6.5).
TYPE LOCATION: Ferry County, Washington; Block Floor Cabin area; 20 yards north of road, 300 yards east of spring, Colville National Forest; NE1/4, SW1/4 of section 7, T. 35 N., R. 34 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 40 degrees to 44 degrees F. and the mean summer temperature is about 47 degrees F. The upper part of the 10- to 40-inch control section contains more than 30 percent glassy pyroclastic materials and 0 to 20 percent coarse fragments. The lower part of the control section contains 5 to 18 percent clay and more than 15 percent coarser than very fine sand by weighted average; and contains 5 to 35 percent coarse fragments by volume. The soils are moderately acid to slightly acid. The mollic or umbric epipedon ranges from 10 to 15 inches thick.
The A and AB horizons have value of 4 or 5 dry and chroma of 1 or 2 dry or moist. They have weak to moderate granular or subangular blocky structure.
The Bw horizon has value of 6 or 7 dry and chroma of 3 or 4 dry. It is heavy ashy loam or ashy clay loam.
The C horizons are layered silt loam, loam, sandy loam, and loamy coarse sand that is gravelly in most pedons. The lower C horizon has some clay films or clay bridging sand grains in some pedons.
COMPETING SERIES: These are no competing series.
GEOGRAPHIC SETTING: Edds soils occur on plains and mountain slopes at elevations of 3,500 to 7,000 feet. Slopes are 15 to 65 percent. They formed in volcanic ash over glacial till. These soils are in a cold subhumid climate with a mean annual temperature of 38 degrees to 42 degrees F., a mean annual precipitation of 20 to 30 inches, and a frost-free period of 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Growden, Leonardo, and Manley soils and the competing Tenas soils. Growden soils are loamy-skeletal. Leonardo and Manley soils are loamy-skeletal in the lower part of the particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Woodland, grazing, and wildlife browse and cover. Native vegetation is Douglas-fir, western larch, lodgepole pine, subalpine fir, and at the lower elevations, ponderosa pine. The understory is serviceberry, common snowberry, common chokeberry, rose, wild strawberry, yarrow, and mullen.
DISTRIBUTION AND EXTENT: Northeastern Washington. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ferry County (North Ferry Area), Washington, 1971.
REMARKS: This draft reflects a change in classification from Medial over loamy, mixed Typic Cryandepts to ashy over loamy, glassy over isotic Humic Xeric Vitricryands. Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the mineral surface to 12 inches and a cambic horizon from 12 to 24 inches. The lower elevations mapped as Edds appear to be frigid and the higher elevations cryic. The series needs further study.