LOCATION PUYALLUP WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, isotic over mixed, mesic Vitrandic Haploxerolls
TYPICAL PEDON: Puyallup fine sandy loam - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 4 inches; very dark brown (l0YR 2/2) fine sandy loam, dark grayish brown (l0YR 4/2) dry; moderate medium and coarse granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; slightly acid (pH 6.2); abrupt smooth boundary. (3 to 8 inches thick)
A2--4 to 8 inches; very dark grayish brown (l0YR 3/2) loam, dark grayish brown (l0YR 4/2) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; moderately acid (pH 6.0); clear smooth boundary. (3 to 5 inches thick)
A3--8 to l8 inches; dark brown (l0YR 3/3) fine sandy loam, grayish brown (l0YR 5/2) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine roots; many fine and medium and few large pores; slightly acid (pH 6.3); abrupt wavy boundary. (8 to 20 inches thick)
2Cl--l8 to 27 inches; dark brown (l0YR 3/3) loamy sand, grayish brown (l0YR 5/2) dry; single grained; loose; few fine roots; slightly acid (pH 6.4); abrupt wavy boundary. (8 to l5 inches thick)
2C2--27 to 60 inches; very dark grayish brown (2.5Y 3/2) gravelly sand, grayish brown (2.5Y 5/2) dry; single grained; loose; 20 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Clark County, Washington; along Lower East Fork Lewis River Road about 2,240 feet north and 600 feet west of the southeast corner of sec. l9, T. 4 N., R. 2 E.
RANGE IN CHARACTERISTICS: Depth to the 2C horizon is l5 to 30 inches. The mollic epipedon is 10 to 20 inches thick. Estimated mean annual soil temperature at a depth of 20 inches ranges from 47 to 53 degrees F. These soils are usually moist, but they are dry in all parts between depths of 7 and 20 inches for 60 to 75 consecutive days. The upper part of the particle-size control section has 5 to l5 percent clay and includes fine sandy loam or loam. The lower part has 0 to 5 percent clay. The soil ranges from neutral to moderately acid. The A horizon has hue of l0YR or 2.5Y, value of 2 or 3 moist, 3 to 5 dry, and chroma of l through 3 moist and dry. Below 10 inches it is loam or fine sandy loam. Some pedons have a B or C horizon.
The 2C horizon has hue of l0YR or 2.5Y, value of 32through 5 moist, 4 through 7 dry, and chroma of 1 through 4 moist and dry. It is sand, loamy sand, or gravelly sand and has 0 to 20 percent pebbles.
COMPETING SERIES: These are the Boesel, Chamokane, Newberg, and Snakelum series in other families. Boesel soils are frigid. Chamokane soils have a mollic epipedon more than 20 inches thick. Newberg soils lack contrasting textures within the l0- to 40-inch control section. Snakelum soils lack a mollic epipedon and have a regular decrease in organic matter content as depth increases.
GEOGRAPHIC SETTING: These soils are on floodplains and low stream terraces at elevations of 20 to 650 feet. The soils formed in mixed recent alluvium. The climate is humid; summers are cool and dry, and winters are mild and moist. Average annual precipitation is 35 to 60 inches. Mean January temperature is 37 degrees F, mean July temperature is 62 degrees F, mean annual temperature is about 50 degrees F, and frost-free season is l70 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Briscot, Mt. Vernon, Oridia, Pilchuck, Puget, and Sultan soils. Briscot, Oridia, and Puget soils have an aquic moisture regime. Pilchuck soils are sandy throughout. Mt. Vernon soils are medial over loamy. Sultan soils are fine-silty and have an ochric epipedon.
DRAINAGE AND PERMEABILITY: Well drained; very slow runoff; moderately rapid permeability in the upper part of the control section and rapid below. These soils are subject to occasional brief periods of flooding from November to April unless protected.
USE AND VEGETATION: Used for cropland. Principal crops are hay, pasture, and row crops. Native vegetation is Douglas-fir, western redcedar, bigleaf maple, black Cottonwood, western hemlock, and red alder, with an understory of trailing blackberry, salmonberry, Oregon-grape, western swordfern, vine maple, and western brackenfern.
DISTRIBUTION AND EXTENT: Western Washington and possibly western Oregon. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snohomish County, Washington, l936.
REMARKS: Classification only updated 3/94 because of recent amendments to Soil Taxonomy. Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 18 inches and a textural change to sandy material at 18 inches. Organic carbon content is assumed to decrease irregularly with depth.