LOCATION SNAKELUM WAEstablished Series
TAXONOMIC CLASS: Sandy, isotic, mesic Ultic Haploxerolls
TYPICAL PEDON: Snakelum coarse sandy loam, cropland, on a south facing slope of 5 percent and elevation of 60 meters. (Colors are for moist soil unless otherwise noted)
A--0 to 25 centimeters; black (10YR 2/1) coarse sandy loam, very dark brown (10YR 2/2) dry; moderate fine and medium granular structure; slightly hard, friable, nonsticky, nonplastic; common very fine to fine and few medium roots; many fine to medium tubular pores; moderately acid (pH 5.9); abrupt smooth boundary. (15 to 40 centimeters thick)
AB--25 to 46 centimeters; very dark brown (10YR 2/2) sandy loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; hard, firm, nonsticky, nonplastic; common very fine to fine roots; many fine to medium tubular pores; moderately acid (pH 5.9); clear smooth boundary. (10 to 30 centimeters thick)
Bw--46 to 61 centimeters; dark grayish brown (10YR 4/2) sandy loam, light brownish gray (10YR 6/2) dry; moderate fine subangular blocky structure; hard, very firm, nonsticky, nonplastic; few very fine roots; common fine irregular pores; moderately acid (pH 6.0); clear smooth boundary. (15 to 30 centimeters thick)
2BC--61 to 122 centimeters; dark grayish brown (10YR 4/2)loamy coarse sand, light brownish gray (10YR 6/2) dry; single grain; loose, nonsticky, nonplastic; few very fine roots; many fine to medium interstitial pores; slightly acid (pH 6.4); gradual smooth boundary. (30 to 90 centimeters thick)
2C--122 to 152 centimeters; olive brown (2.5Y 4/3) coarse sand, light yellowish brown (2.5Y 6/3) dry; single grain; loose, nonsticky, nonplastic; many fine to medium interstitial pores; 10 percent gravel; slightly acid (pH 6.4)
TYPE LOCATION: Island County, Washington; Smith Prairie, 3 miles east of Coupeville; 200 meters north, 480 meters west of the southeast corner of section 1, T. 31 N., R. 1 E. Willamette Baseline Meridian; Coupeville, Washington USGS quadrangle; Latitude 48 deg, 11 min, 51 seconds North, Longitude 122 deg, 37 min, 20 seconds West; UTM 528070 meters E, 5338320 meters N, zone 10 NAD83.
RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.
Moisture control section - dry 75 to 90 consecutive days following the summer solstice
Mean annual soil temperature - 11 to 12 degrees C
Mollic epipedon thickness - 25 to 50 centimeters
Reaction - slightly acid or strongly acid
Base saturation by ammonium acetate - greater than 50 percent within the profile
Base saturation by sum of cations less than 75 percent between 25 and 75 cm
Particle size control section:
Clay content - 2 to 18 percent
Rock fragments 0 to 35 percent gravel, 0 to 5 percent cobbles, 0 to 35 percent total
A horizon
Hue - 10YR or 7.5YR
Value 2 or 3 moist, 2 to 4 dry
Chroma - 1 or 2 moist and dry
Rock fragments - 0 to 15 percent gravel
AB horizon
Hue - 10YR or 7.5YR
Value - 2 or 3 moist, 3 to 5 dry
Chroma - 1 to 3 moist and dry
Texture - SL or FSL
Rock fragments - 0 to 15 percent gravel
Bw horizon
Hue - 10YR or 7.5YR
Value - 4 or 5 moist, 5 to 7 dry
Chroma - 2 or 3 moist and dry
Texture - SL or FSL
Rock fragments - 0 to 35 percent gravel
2BC horizon
Hue - 10YR or 7.5YR
Value - 5 to 7 dry and 4 or 5 moist
Chroma - 2 or 3 moist and dry
Texture - LCOS, LS, or COS
Rock fragments - 0 to 35 percent gravel
2C horizon
Hue - 2.5Y or 10YR
Value - 4 to 6 moist, 5 to 7 dry
Chroma - 1 to 3 moist and dry
Texture - COS or LCOS
Rock fragments - 0 to 50 percent gravel, 0 to 5 percent cobbles
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Snakelum soils formed in eolian sands and compacted glacial outwash sands and gravel on glacial outwash plains at elevations of 0 to 90 meters. These soils are in a mild marine climate with cool, dry summers and mild, moist winters. Mean annual precipitation ranges from 460 to 635 millimeters. Mean annual air temperature ranges from 10 to 11 degrees C. Frost-free season is 200 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hoypus soils and San Juan soils. Hoypus soils lack a mollic epipedon and have a sandy-skeletal particle-size control section. Hoypus soils form under forest canopy on similar landscape positions. San Juan soils are pachic and formed on dunes and hillslopes of glacial outwash plains.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained. Saturated hydraulic conductivity is high in the A, AB, and Bw horizons and very high in the 2BC and 2C horizons.
USE AND VEGETATION: Snakelum soils are used for homesites, food and forage crop production, wildlife habitat, and livestock grazing. Potential natural vegetation may include widely spaced Oregon white oak, Pacific madrone, and Douglas-fir but is primarily prairie vegetation including Roemer's fescue, western bracken fern, bald hip rose, snowberry, oceanspray, and trailing blackberry.
DISTRIBUTION AND EXTENT: Island County, western Washington; MLRA 2, North. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Island County, Washington, 1950.
REMARKS: Diagnostic horizon and features recognized in this pedon include:
Mollic epipedon - the zone from the surface to 46 cm (A and AB horizons)
Cambic horizon - the zone from 46 to 61 cm (Bw horizon)
Lithologic discontinuity 61 to 152 cm (2BC and 2C horizons)
Particle-size control section - the zone from 25 to 100 cm (AB, Bw, and upper part of 2BC horizons)
A revision in 2006 included a change in classification based on field investigations and lab data from similar soils. The previous classification was coarse-loamy, mixed, superactive, mesic Humic Dystroxerepts.