LOCATION BELFAST WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, isotic, nonacid, mesic Aquandic Xerofluvents
TYPICAL PEDON: Belfast silt loam, cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 5 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; slightly hard, friable, and slightly plastic; many roots; moderately acid (pH 6.0); abrupt wavy boundary. (4 to 8 inches thick)
C1--5 to 12 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; moderate medium and coarse granular structure; slightly hard, friable, and slightly plastic; many roots; slightly acid (pH 6.4); clear smooth boundary. (4 to 12 inches thick)
C2--12 to 15 inches; dark grayish brown (2.5Y 4/2) heavy silt loam, light brownish gray (2.5Y 6/2) dry; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common roots; many fine and medium pores; slightly acid (pH 6.4); clear wavy boundary. (2 to 8 inches thick)
C3--15 to 20 inches; dark grayish brown (2.5Y 4/2) fine sandy loam, light brownish gray (2.5Y 6/2) dry; massive; soft, friable; common roots; slightly acid (pH 6.4); clear smooth boundary. (4 to 8 inches thick)
C4--20 to 28 inches; dark grayish brown (2.5Y 4/2) loam, light brownish gray (2.5Y 6/2) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium pores; few roots; slightly acid (pH 6.4); clear smooth boundary. (6 to 10 inches thick)
C5--28 to 31 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; massive; slightly hard, friable and slightly plastic; few roots; few medium pores; slightly acid (pH 6.4); clear wavy boundary. (2 to 5 inches thick)
C6--31 to 48 inches; dark grayish brown (2.5Y 4/2) fine sandy loam, light brownish gray (2.5Y 6/2) dry; massive; slightly hard, friable and slightly plastic; few roots; slightly acid (pH 6.5); clear smooth boundary. (10 to 20 inches thick)
C7--48 to 60 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; massive; hard, firm, sticky and plastic; few roots; slightly acid (pH 6.5).
TYPE LOCATION: Jefferson County, Washington; lower Duckabush River Valley, 0.3 mile west of U. S. Highway 101 and 200 feet south of Duckabush Road in the northeast corner of the SE1/4 SW1/4 sec. 16, T. 25 N., R. 2 W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 49 degrees to 52 degrees F. These soils are usually moist but are dry for a period of 45 to 60 consecutive days in the summer. The series control section has 0 to 15 percent rock fragments by volume. These soils are free of mottles above have a water table as high as 3.5 to 5 feet at times in fall and winter. Reaction is slightly to moderately acid throughout.
The A or Ap horizon has hue of 10YR or 2.5Y and value of 2 through 4 moist and 4 through 6 dry, and chroma of 2 through 4 moist and dry.
The upper part of the C horizon has hue of 10YR through 5Y, value of 4 or 5 moist, 6 or 7 dry, and chroma of 2 or 3 moist and dry. It is silt loam, loam, fine sandy loam, or very fine sandy loam. It is massive or has weak or moderate subangular blocky structure. Some pedons have dark brown stains in root channels.
The lower part of the C horizon has hue of 10YR through 5Y, value of 3 through 6 moist, 6 or 7 dry, and chroma of 2 through 4 moist. Some pedons have dark brown mottles below a depth of 30 inches. This horizon is stratified silt loam, loam, fine sandy loam, sandy loam, gravelly loamy sand and loamy sand. Thin gravel strata are present in some pedons.
COMPETING SERIES: These are the Fallon and Greenhorn series. Fallon soil are mildly alkaline or moderately alkaline throughout and have mottles at a depth of 15 to 24 inches. Greenhorn soils are mottled below 0 to 11 inches and have iron segregations throughout the particle- size control section.
GEOGRAPHIC SETTING: Belfast soils are on nearly level flood plains at elevations of 20 to 600 feet. They formed in stratified alluvium. The climate is cool and dry in summer and mild and wet in winter. Annual precipitation ranges from 50 to 70 inches. Average January temperature is about 40 degrees F.; average July temperature is about 60 degrees F. The frost-free season is about 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Indianola, Juno, Lummi, Nooksack, Norma, Oridia, and Puget soils. Indianola soils have a sandy control section. Juno soils are sandy-skeletal. Lummi and Puget soils are fine-silty and poorly drained. Nooksack soils have a mollic epipedon and are coarse-silty. Norma soils are poorly drained and have prominent mottles within 20 inches of the surface. Oridia soils are coarse-silty and poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability. This soil is subject to occasional very brief periods of flooding from November through March. A high water table is present as high as 3.5 to 5.0 feet at times from November through March.
USE AND VEGETATION: Used mostly for hay and pasture. Native vegetation is western redcedar, western hemlock, Douglas-fir, willow, red alder, bigleaf maple, with an understory of vine maple, salmonberry, salal, western swordfern and western brackenfern.
DISTRIBUTION AND EXTENT: Northwestern Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, 1953.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 5 inches, a particle-size control section from 10 to 40 inches that has an assumed irregular decrease in organic carbon and these soils are assumed to have more than 0.2 percent organic carbon at 60 inches of depth.