LOCATION SCLOME WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Fluvaquentic Hapludolls
TYPICAL PEDON: Sclome silty clay loam - on a nearly level pasture at 2,520 feet elevation. (Colors are dry soil unless otherwise stated.)
A--0 to 13 inches; very dark gray (10YR 3/1) silty clay loam, black (N 2/0) moist; strong fine and medium subangular blocky structure parting to strong fine granular; hard, firm, moderately sticky and moderately plastic; many very fine, common fine, and few medium roots; slightly acid (pH 6.4); abrupt wavy boundary. (10 to 24 inches thick)
2Bw--13 to 18 inches; grayish brown (10YR 5/2) and pale brown (10YR 6/3) heavy silt loam, very dark grayish brown (10YR 3/2) and brown (10YR 4/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; pressure faces on face of peds and root channels; neutral (pH 6.6); clear wavy boundary. (5 to 12 inches thick)
3BAgb--18 to 28 inches; grayish brown (2.5Y 5/2) and light brownish gray (2.5Y 6/2) clay loam, very dark grayish brown (2.5Y 3/2) moist and dark grayish brown (2.5Y 4/2) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; pressure faces on faces of peds and root channels; neutral (pH 6.8); clear wavy boundary. (0 to 14 inches thick)
3Bgb--28 to 50 inches; light brownish gray (2.5Y 6/2) and light gray (2.5Y 7/2) heavy sandy loam, grayish brown (2.5Y 5/2) moist; common medium distinct light olive brown (2.5Y 5/4) moist redox concentrations and common medium prominent dark yellowish brown (10YR 4/4) moist redox concentrations; weak medium angular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; few very fine roots; neutral (pH 6.8); clear wavy boundary. (4 to 28 inches thick)
3Cg--50 to 60 inches; light gray (2.5Y 7/2) and 5Y 7/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist and olive (5Y 5/3) moist; many medium distinct yellowish brown (10YR 5/4) moist redox concentrations, dark yellowish brown (10YR 4/4) moist redox concentrations, and common fine distinct dark brown (7.5YR 3/4) moist redox concentrations; massive; hard, firm, moderately sticky and moderately plastic; neutral (pH 6.8).
TYPE LOCATION: Colville Indian Reservation; Ferry County, Washington; about 6-1/2 miles east of the town of Keller; 700 feet south and 1,400 feet west of the northeast corner of sec. 29, T. 30 N., R. 34 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 44 to 46 degrees F. These soils are usually saturated from December through June but are dry between depths of 4 and 12 inches for 30 to 45 consecutive days following the summer solstice. Depth to the seasonal high water table in winter and early spring is 1 to 2 feet below the surface. Thickness of the mollic epipedon is 10 to 16 inches. The particle-size control section averages 22 to 35 percent clay and less than 15 percent mostly fine pebbles. Reaction is slightly acid or neutral.
The A horizon has hue of 10YR or is neutral, value of 4 or 5 dry, 2 or 3 moist, and chroma of 0 through 3 dry or moist. In some pedons, the A horizon is overlain by a thin C horizon 1 to 3 inches thick of recent alluvium, or an Oa horizon 1 to 4 inches thick. Some pedons have an AB, AC or BA horizon below the A horizon.
The 2Bw horizon has hue of 10YR or 2.5Y, value of 5 through 7 dry, 3 or 4 moist, and chroma of 2 through 4 dry or moist. It has weak or moderate, fine or medium blocky structure.
The 3BAgb horizon has value of 5 or 6 dry, 3 or 4 moist. It is clay loam or silty clay loam. Some pedons lack a 3BAgb horizon. Some pedons have a 3Ab horizon. The 3Bgb horizon has value of 4 or 5 moist. It is stratified sandy loam, loam, clay loam, or silty clay loam.
The 3Cg horizon has hue of 2.5Y or 5Y, value of 5 through 7 dry, 3 or 4 moist, and chroma of 1 through 3 dry or moist. It is stratified loamy sand to silty clay loam.
COMPETING SERIES: This is Homelake series. Homelake soils do not have a cambic horizon.
GEOGRAPHIC SETTING: Sclome soils are in valleys and formed in fine alluvium overlying volcanic ash and valley fill. Slopes are 0 to 3 percent. Elevations range from 2,400 to 2,700 feet. The climate is characterized by warm, dry summers and cold, moist winters. The average annual precipitation is 18 to 20 inches. The mean January temperature is about 23 degrees F, the mean July temperature is about 64 degrees F, and the mean annual air temperature is about 43 degrees F. The frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brushercreek, Centralpeak, Dinkelman, Friedlander, Georgecreek, and Spokane soils. All of these soils are well drained. Brushercreek soils lack a mollic epipedon. Dinkelman soils are coarse-loamy. Friedlander soils are fine textured. Georgecreek soils are deep to a paralithic contact. Centralpeak and Spokane soils are moderately deep to a paralithic contact.
DRAINAGE AND PERMEABILITY: Poorly drained, very slow to slow runoff; permeability is moderately slow.
USE AND VEGETATION: Grazing, timber production, non-irrigated hay and pasture, wildlife habitat, and watershed are the principal uses. The native vegetation is Douglas-fir, ponderosa pine, western larch, quaking aspen, thinleaf alder, black hawthorn, and paper birch, with an understory of blue wildrye, northwest cinquefoil, common snowberry, sweetscented bedstraw, and Virginia strawberry.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colville Indian Reservation; Ferry County, Washington, 1987.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from the surface to 13 inches. Beneath the mollic epipedon is a cambic horizon from 13 to 50 inches. The cambic horizon is gleyed from 18 to 50 inches. The soil fails to be buried because the mantle at the surface is altered to be the mollic epipedon and part of the cambic horizon.
This draft reflects a change in classification from Fluvaquentic Haplaquolls to Fluvaquentic Hapludolls based on the lack of redox features in the 3BAgb horizon. The type location for this series may need revisiting to determine if redox features exist in this zone.