LOCATION SARA WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Aquic Palexeralfs
TYPICAL PEDON: Sara silt loam, cultivated. (Colors are for moist soil unless otherwise stated.)
Ap1--0 to 5 inches; dark brown (7.5YR 3/2) silt loam, brown (7.5YR 5/4) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; moderately acid; abrupt smooth boundary.
Ap2--5 to 10 inches; dark brown (7.5YR 3/2) silt loam, brown (7.5YR 5/4) dry; moderate medium platy structure; hard, firm, slightly sticky and slightly plastic; many fine roots; many fine and medium pores; moderately acid; abrupt smooth boundary. (Combined thickness of the Ap horizon is 8 to 14 inches)
B/E1--10 to 17 inches; dark brown (10YR 4/3) silty clay loam, (B part) light yellowish brown (10YR 6/4) dry; common fine faint strong brown (7.5YR 5/6) mottles, reddish yellow (7.5YR 6/6) dry; patchy light gray (10YR 7/2) dry coatings (E part) are apparent on surfaces of peds; moderate fine subangular blocky structure; very hard, firm, sticky and plastic; common fine roots on surfaces of peds; many fine pores; distinct patchy clay films on surfaces of peds; few fine black manganese concretions; strongly acid; abrupt wavy boundary. (5 to 10 inches thick)
B/E2--17 to 25 inches; dark grayish brown (10YR 4/2) silty clay loam. (B part) yellowish brown (10YR 5/4) dry; strong brown (7.5YR 5/6) mottles, reddish yellow (7.5YR 6/8) dry; moderate medium prismatic structure parting to moderate fine angular blocky; extremely hard, firm, sticky, plastic; few fine roots on surfaces of peds; many fine pores; common prominent dark brown (7.5YR 4/4) clay films in pores and on surfaces of peds; few fine black manganese concretions; gray (10YR 6/1) tongues or coatings around peds, (E part) white (10YR 8/1) dry; moderately acid; clear wavy boundary. (7 to 12 inches thick)
B/E3--25 to 38 inches; dark grayish brown (10YR 4/2) silty clay, (B part) pale brown (10YR 6/3) dry; few fine distinct dark brown (7.5YR 3/2) mottles; moderate medium prismatic structure that parts to strong fine angular blocky structure; extremely hard, very firm, very sticky, very plastic; common fine pores; continuous prominent clay films; thick tongues (E part)of gray (10YR 6/1) and white (10YR 8/1) dry; moderately acid; abrupt wavy boundary. (10 to 14 inches thick)
B/E4--38 to 48 inches; dark grayish brown (10YR 4/2) silty clay loam, (B part) pale brown (10YR 6/3) dry; few medium distinct dark reddish brown (5YR 3/3) mottles, (5YR 4/4) dry; moderate medium angular blocky structure; extremely hard, extremely firm, sticky, plastic; common fine pores, continuous prominent clay films; 5 percent black manganese concretions from 3 to 5 mm; dark grayish brown (10YR 4/2) coatings (E part) on vertical faces of peds, light gray (10YR 7/1) dry; strongly acid; gradual wavy boundary. (8 to 12 inches thick)
B/E5--48 to 70 inches; dark brown (10YR 4/3) silty clay loam, (B part) light yellowish brown (10YR 6/4) dry; weak medium and fine subangular blocky structure; extremely hard, very firm, sticky, plastic; few fine pores; continuous prominent clay films; light gray (10YR 7/2) dry, 1/2 to 1 inch tongues (E part) between major ped surfaces; many medium black manganese concretions; moderately acid; clear wavy boundary. (19 to 24 inches thick)
B/E6--70 to 96 inches; strong brown (7.5YR 5/8) silty clay loam, (B part) reddish yellow (7.5YR 6/8) dry; weak coarse prismatic structure that parts to moderate medium and moderate fine angular blocky structure; extremely hard, very firm, very sticky, very plastic; few fine pores; continuous prominent clay films; common coarse black manganese concretions; white (10YR 8/1) dry, 1/2 to 1 inch thick tongues (E part) extending downward between major ped surfaces (4 to 6 inches apart); moderately acid.
TYPE LOCATION: Clark County, Washington; 1,900 feet east of County Road 19 on the William Blank Road and 300 feet north in field; SW1/4 SE1/4 NE1/4, section 4, T.3N., R.1E.
RANGE IN CHARACTERISTICS: These soils are usually moist and have a perched water table during the winter and early spring, but are dry in the moisture control section for 45 to 60 consecutive days following summer solstice. The average annual soil temperature at a depth of 20 inches ranges from 50 to 52 degrees F. The soils are moderately acid or strongly acid, however, base saturation by sum of cations is assumed to be 35 to 50 percent throughout the argillic horizon.
The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 3 to 5 dry, and chroma of 2 or 3 moist and 2 to 4 dry. It is silt loam or silty clay loam.
The B part of the B/E horizon has hue of 10YR or 7.5YR, value of 4 or 5 moist and 5 or 6 dry, and a chroma of 2 through 8. Texture ranges from heavy silty clay loam to silty clay, with 35 to 50 percent clay. It is sticky and plastic or very sticky and very plastic, firm to very firm, and very hard to extremely hard.
COMPETING SERIES: These are the Bow, Coveland, Coweeman, Hardscrabble, Prather, and Scamman series. Bow and Coveland soils have a gravelly E horizon and have a base saturation, by sum, of more than 75 percent in some part of the argillic horizon. Coweeman soils have a chroma of 2 or less in the matrix throughout the argillic horizon. Hardscrabble soils have an abrupt textural change at the top of the argillic horizon. Prather soils are mottled in the lower Bt horizon and lack a perched water table during winter and spring. Scamman soils have an ochric epipedon and base saturation (by sum) of more than 75 percent in some part of the argillic horizon.
GEOGRAPHIC SETTING: Sara soils are on terraces and terrace escarpments. Slopes are 0 to 40 percent. Elevations range from 250 to 450 feet. These soils formed in alluvium. Sara soils occur in a humid marine climate having relatively cool, dry summers and mild, wet winters. The average annual precipitation is about 45 inches. The average January temperature is about 37 degrees F.; the average July temperature is about 64 degrees F.; and average annual temperature is about 50 degrees F. The average frost free season is about 185 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gee and Odne soils. Gee and Odne soils are fine-silty. In addition, Odne soils lack albic material that tongues into the argillic horizon and Odne soils have an aquic moisture regime.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to very rapid runoff; moderately slow permeability. A perched water table is as high as 1 to 2 feet from December to April.
USE AND VEGETATION: Used mainly for hay, pasture, and small grain. Some strawberries and potatoes are grown. Native vegetation is Douglas fir, red alder, western redcedar, and bigleaf maple, with an understory of salal, Oregongrape, western swordfern, western brackenfern, salmonberry, and Douglas spirea.
DISTRIBUTION AND EXTENT: Southwestern Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clark County (Clark County Area), Washington, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the surface to 10 inches, and an argillic horizon from 10 to 96 inches that has tongues and coatings of albic material throughout. Base saturation, by sum, is assumed to be 35 to 60 percent throughout the argillic horizon.