LOCATION SULTAN WAEstablished Series
TAXONOMIC CLASS: Fine-silty, isotic, mesic Aquandic Dystroxerepts
TYPICAL PEDON: Sultan silt loam - pasture. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 9 inches; very dark grayish brown (10YR 3/2) silt loam, light brownish gray (10YR 6/2) dry; moderate medium granular structure; hard, firm, moderately sticky, moderately plastic; many roots; slightly acid (pH 6.4); abrupt smooth boundary. (6 to 10 inches thick)
Bw1--9 to 21 inches; yellowish brown (10YR 5/4) silty clay loam, pale brown (10YR 6/3) dry; moderate fine subangular blocky structure; hard, friable, moderately sticky, moderately plastic; many roots; slightly acid (pH 6.4); clear wavy boundary. (10 to 14 inches thick)
Bw2--21 to 24 inches; light olive brown (2.5Y 5/4) silt loam, pale yellow (2.5Y 7/4) dry; many medium prominent yellowish brown (10YR 5/8) mottles; moderate medium subangular blocky structure; hard, very friable, slightly moderately sticky, slightly plastic; common roots; neutral (pH 6.6); clear wavy boundary. (2 to 5 inches thick)
Bg--24 to 48 inches; grayish brown (2.5Y 5/2) silty clay loam, pale yellow (2.5Y 8/2) dry; many medium prominent yellowish brown (10YR 5/8) mottles; moderate medium prismatic structure; slightly hard, very friable, moderately sticky, moderately plastic; few roots; neutral (pH 6.6); clear wavy boundary. (20 to 30 inches thick)
Cg--48 to 66 inches; olive gray (5Y 5/2) very fine sandy loam stratified with medium sand, light gray (2.5Y 7/2) dry; common fine prominent yellowish red (5YR 4/6) mottles; massive; slightly hard, very friable; few roots; very strongly acid (pH 4.8).
TYPE LOCATION: King County, Washington; 2,140 feet west, 250 feet north of southeast corner of sec. 9, T. 25 N., R. 7 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is estimated to range from 47 to 52 degrees F. These soils are usually moist, but are dry in all parts between depths of 3 and 12 inches for 45 to 60 consecutive days during the summer. The particle-size control section averages less than 5 percent coarse fragments, less than 15 percent coarser than very fine sand, and has 20 to 35 percent clay.
The Ap horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 or 3 moist and dry. It has moderate to weak structure. Reaction is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 or 5 moist, 6 or 7 dry, and chroma of 3 or 4 moist or dry. Texture is silt loam or silty clay loam. It has moderate or weak structure. Reaction is slightly acid or neutral.
The Bg horizon has hue of 5Y or 2.5Y, value of 4 to 7 moist, 5 to 8 dry, and chroma of 1 or 2 moist or dry. Textures is silt loam, very fine sandy loam, or silty clay loam. Reaction is slightly acid or neutral.
The Cg horizon has hue of 5Y or 2.5Y, value of 4 to 7 moist, 5 to 8 dry, and chroma of 0 to 2 moist or dry. Texture is stratified and ranges from silt loam to sand. Reaction ranges from very strongly acid to neutral.
COMPETING SERIES: These are Belle and Queets series in other families. Belle soils have 10YR hue throughout and are very strongly acid and strongly acid. Belle and Queets soils have a cambic horizon and a udic moisture regime.
GEOGRAPHIC SETTING: The Sultan series are in the parts of river valleys that have slightly undulating microrelief at elevations ranging from near sea level to 120 feet. They formed in stratified loamy alluvium. The climate is marine. Average January temperature is 38 degrees F, average July temperature is 64 degrees F, and mean annual temperature is 50 degrees F. The average annual precipitation ranges from 35 to 55 inches and most of it falls as rain during winter. Snow is infrequent. The frost-free season ranges from 150 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nooksack, Pilchuck, Puget, Puyallup, and Woodinville soils. Nooksack soils are coarse-silty and have a mollic epipedon. Pilchuck soils are sandy. Puyallup soils have a mollic epipedon and are coarse-loamy over sandy or sandy-skeletal. Woodinville soils have an aquic moisture regime and thin lenses of organic material within the series control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: Most of the Sultan soils have been cleared and are used for growing seeded grass pasture or row crops. Native vegetation consists of Douglas-fir, red alder, and western redcedar with an understory of Douglas spirea, trailing blackberry, salmonberry, thimbleberry. Oregon-grape, willow, western swordfern, vine maple, and tree seedlings.
DISTRIBUTION AND EXTENT: The series is of moderate extent in the Puget Sound Basin of Western Washington.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snohomish County, Washington, 1937.
REMARKS: Classification updated 3/94 and 1/00 because of amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 9 inches, a cambic horizon from 9 to 24 inches, a particle-size control section that is assumed to have an irregular decrease in organic carbon and the soil is assumed to have more than 0.2 percent organic carbon from 50 to 60 inches. Base saturation is less than 60 percent (NH4Oac) from 10 to 30 inches and is based on lab data from the associated Puget series.