LOCATION EDGEWICK WA
Established Series
Rev. AG/RJE/TLA
06/2011
EDGEWICK SERIES
The Edgewick series consists of very deep, well drained soils formed in alluvium on river terraces and flood plains. Mean annual precipitation is about 60 inches and average annual temperature is about 50 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Fluventic Humudepts
TYPICAL PEDON: Edgewick silt loam - in pasture at 400 feet elevation. (Colors are for moist soils unless otherwise noted.)
Ap--0 to 8 inches; very dark brown (10YR 2.5/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; strongly acid (pH 5.4); clear smooth boundary. (7 to 12 inches thick)
Bwl--8 to 10 inches; olive brown (2.5Y 4/4) silt loam, light gray (2.5Y 7/2) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; moderately acid (pH 5.6); clear wavy boundary.
Bw2--10 to 20 inches; olive brown (2.5Y 4/4) fine sandy loam, light gray (2.5Y 7/2) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; moderately acid (pH 5.6); clear wavy boundary. (Combined thickness of the Bw horizon is 10 to 25 inches)
C1--20 to 33 inches; olive brown (2.5Y 4/4) sandy loam, pale yellow (2.5Y 7/4) dry; massive; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 10 percent gravel; moderately acid (pH 5.8); gradual wavy boundary.
C2--33 to 46 inches; olive brown (2.5Y 4/4) loamy sand, light gray (2.5Y 7/2) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 10 percent gravel; moderately acid (pH 5.8); clear wavy boundary. (Combined thickness of the C horizon is 20 to 38 inches)
2C3--46 to 60 inches; dark grayish brown (2.5Y 4/2) very gravelly sand, light brownish gray (2.5Y 6/2) dry; single grain; loose; many very fine irregular pores; 50 percent gravel; neutral (pH 6.6).
TYPE LOCATION: King County, Washington; 2,500 feet north and 1,000 feet east of the southwest corner, sec. 10, T. 23 N., R. 8 E.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry for a short period of less than 45 consecutive days following summer solstice. The mean annual soil temperature is 47 to 49 degrees F. Depth to the 2C horizon is 40 to more than 60 inches. The umbric epipedon is 7 to 12 inches thick.
The Ap horizon has hue of 7.5YR, 10YR or 2.5Y, and value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist, 2 through 4 dry. Reaction is very strongly acid to moderately acid.
The Bw horizon has hue of 7.5YR, 10YR or 2.5Y, value of 3 through 5 moist, 4 through 7 dry, and chroma of 2 through 4 moist and dry. It is silt loam, loam, or fine sandy loam. It is moderately acid or slightly acid.
The C horizon has hue of 10YR or 2.5Y, value of 5 through 7 dry, and chroma of 2 through 4 moist and dry. It is sandy loam in the upper part grading to sand or loamy sand in the lower part. In some pedons it is gravelly or very gravelly. It is slightly acid or neutral.
The 2C horizon has hue of 10YR, 2.5Y or 5Y, value of 2 through 5 moist, 4 through 6 dry, and chroma of 1 to 4 moist and dry. It is sandy loam, coarse sand or loamy sand. Rock fragments range from 35 to 60 inches. Reaction is slightly acid or neutral. Depth to the 2C horizon is more than 60 inches in some pedons.
COMPETING SERIES: These are the
Nekoma and
Rosman series. Nekoma soils have an umbric epipedon 10 to 20 inches thick. Rosman soils have a mean annual soil temperature of 55 to 59 degrees F.
GEOGRAPHIC SETTING: Edgewick soils are on alluvial terraces at elevations of 50 to 500 feet. Slopes are 0 to 3 percent. They formed in alluvium. Edgewick soils are in a marine climate with cool, wet winters and warm, dry summers. The mean annual precipitation is 50 to 70 inches. Mean January temperature is 38 F, mean July temperature is 63 degrees F, and the mean annual air temperature is about 50 degrees F. The frost-free season is 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Nooksack,
Oridia,
Salal,
Seattle, and
Si soils. Nooksack soils have a mollic epipedon and are coarse-silty. Oridia and Si soils have an ochric epipedon and are coarse-silty. In addition, Oridia soils have an aquic moisture regime. Salal soils have an umbric epipedon more than 20 inches thick and are coarse-silty. Seattle soils are Histosols. Si soils have an ochric epipedon and are coarse-silty.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability. A perched water table is as high as 3 to 4 feet at times from February through April. Edgewick soils are subject to occasional, brief periods of flooding from November through March unless protected.
USE AND VEGETATION: Used for hay and pasture, woodland, and homesites. The native vegetation is Douglas-fir, red alder, and western redcedar with an understory of vine maple, trailing blackberry, salmonberry, Oregon oxalis, western swordfern, red elderberry, and Oregongrape.
DISTRIBUTION AND EXTENT: Puget Lowlands, in western Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: King County, Washington, 1943.
REMARKS: Diagnostic horizons and features recognized in this pedon are;
umbric epipedon--from the surface to 8 inches
cambic horizon from 8 to 20 inches.
National Cooperative Soil Survey
U.S.A.