LOCATION WELLSDALE OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Aquultic Haploxeralfs
TYPICAL PEDON: Wellsdale loam, woodland, on a 2 percent slope at an elevation of 431 feet. (Colors are for moist soils unless otherwise noted.)
A1--0 to 2 inches; dark yellowish brown (10YR 3/4) loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure parting to moderate medium and coarse granular; moderately hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine irregular, common fine and few medium tubular pores; strongly acid (pH 5.3); clear wavy boundary. (2 to 6 inches thick)
A2--2 to 8 inches; dark yellowish brown (10YR 3/4) loam, yellowish brown (10YR 5/4) dry; weak fine and medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine, common fine and few medium tubular pores; strongly acid (pH 5.3); clear smooth boundary. (4 to 7 inches thick)
BA--8 to 24 inches; dark brown (7.5YR 3/4) loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; many very fine, common fine and few medium tubular pores; strongly acid (pH 5.1); clear smooth boundary. (7 to 20 inches thick)
Bt1--24 to 34 inches; brown (7.5YR 4/4) loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and few fine tubular pores; few faint clay films on faces of peds and surfaces along pores; common prominent black (10YR 2/1) manganese films; common prominent grayish brown (2.5Y 5/2) iron depletions; common distinct strong brown (7.5YR 4/6) iron concentrations; strongly acid (pH 5.2); clear smooth boundary. (10 to 25 inches thick)
Bt2--34 to57 inches; brown (7.5YR 4/4) clay loam, strong brown (7.5YR 5/6) and reddish yellow (7.5YR 6/6) dry; strong medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; common very fine and few fine roots; common very fine and few fine tubular pores; common prominent clay films on faces of peds and surfaces along pores and root channels; common prominent sand coats on faces of peds; common prominent black (10YR 2/1) manganese films; common distinct strong brown (7.5YR 4/6) iron concentrations; strongly acid (pH 5.2); clear wavy boundary. (10 to 30 inches thick)
BCt---57 to 65 inches; strong brown (7.5YR 5/6), brown (7.5YR 5/4) and light brown (7.5YR 6/4) clay loam, reddish yellow (7.5YR 6/6) and light gray (10YR 7/2) dry; weak medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; many very fine and common fine tubular pores; common prominent clay films on faces of peds, few prominent clay films on surfaces along pores and root channels; few prominent sand coats on faces of peds; common prominent black (10YR 2/1) manganese films; common prominent weak red (2.5YR 5/2) iron depletions; common distinct strong brown (7.5YR 4/6) iron concentrations; very strongly acid (pH 5.0 )
TYPE LOCATION: Yamhill County, Oregon; about 2.5 miles east of Carlton, Oregon; about 1,700 feet wet and 1,100 feet north of the SE corner of section 24, T.3S., R.4W., Willamette Meridian. (Latitude 45 degrees, 17 minutes, 29 seconds N. and Longitude 123 degrees, 07 minutes, 15 seconds W. NAD 83); Dundee, Oregon USGS 7.5 minute topographic quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 52 degrees to 55 degrees F. The soils are usually moist but are dry for 45 to 60 consecutive days between depths of 4 and 12 inches following the summer solstice. Depth to aquic conditions and redox depletions with chroma of 2 or less is 20 to 30 inches. The particle-size control section is 25 to 35 percent clay with 30 to 40 percent sand of which 15 percent or more is fine sand or coarser. It has 0 to 30 percent total pararock fragments derived from sandstone or tuffaceous materials. The solum ranges from 30 to 60 inches thick and has hue of 10YR or 7.5YR.
The A horizon has value of 2 or 3 moist, 4 to 6 dry and chroma of 3 or 4 moist and dry. Texture is loam with 15 to 27 percent clay. It has 0 to 3 percent gravel. Reaction is moderately acid or strongly acid.
The BA or AB horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 4 moist and 4 to 6 dry. Texture is loam or clay loam with 20 to 30 percent clay. It has 0 to 15 percent paragravel. Reaction is moderately acid or strongly acid.
The Bt horizon has value of 4 or 5 moist, 5 or 6 dry and chroma of 4 to 6 moist and dry. The upper part is loam or clay loam with 24 to 35 percent clay and 0 to 15 percent paragravel. The fine-earth texture of the lower part is loam or clay loam with 25 to 40 percent clay and 0 to 35 percent paragravel. It has up to 50 percent sand coats on faces of peds. Reaction is strongly acid or moderately acid in the upper part and strongly acid in the lower part.
The BCt horizon has value of 4 to 6 moist, 5 to 8 dry and chroma of 3 to 8 moist and 2 to 8 dry. The fine-earth texture is loam or clay loam with 25 to 40 percent clay. It has 0 to 50 percent paragravel. Reaction is very strongly acid or strongly acid.
COMPETING SERIES: There are no competing series. Soils with a superactive mineralogy include the Quatama and Stockel soils.
Quatama soils: do not have sand coats on faces of peds; have stratified layers of sandy loam to loamy sand below depths of 40 inches in some pedons; occur on adjacent lower alluvial terraces
Stockel soils: have redox concentrations and redox depletions with chroma of 2 or less above depths of 20 inches; occur on foot slopes in swale positions or as narrow drainageways dissecting old alluvial terraces
GEOGRAPHIC SETTING: Wellsdale soils occur in the summit (interfluve geomorphic component) and shoulder positions (head slope and side slope geomorphic components) on broad, gently sloping tops and undulating slopes of low hills. Slopes are 2 to 30 percent. Elevation is 200 to 700 feet. The soils formed in colluvium and residuum derived from marine tuffaceous sandstone and siltstone of the Spencer Formation. The climate is characterized by warm, wet winters and hot, dry summers. The mean annual precipitation is 40 to 60 inches. The mean annual temperature is 50 to 54 degrees F. The average January temperature is 39 to 40 degrees F. and the average July temperature is 65 to 67 degrees F. The frost-free season is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bellpine, Carlton, Chehulpum, Dupee, Hazelair, Jory, Panther, Sitton, Steiwer, Veneta, and Willakenzie soils. Bellpine soils are fine-textured, 20 to 40 inches deep to a paralithic contact, have less than 35 percent base saturation in the argillic horizon, and occur on adjacent higher foothills. Carlton soils have a mollic epipedon and occur on adjacent foot slopes and low terraces. Chehulpum soils are less than 20 inches deep to a paralithic contact, and occur on low hills and foothills. Dupee soils are somewhat poorly drained, fine textured, and occur in the most concave part of drainageways. Hazelair soils are very fine textured, lack an argillic horizon and occur on low hills and foothills. Jory soils have hue redder than 7.5YR, are fine textured have less than 35 percent base saturation in the argillic horizon, and occur on adjacent higher foothills. Panther soils are poorly drained, very fine textured, and occur in swales and concave drainageways on low hills and foothills. Sitton soils do not have iron depletions or concentrations within 40 inches of the soil surface. Steiwer soils are 20 to 40 inches deep to a paralithic contact, have a mollic epipedon 10 to 20 inches thick, and occur on low hills and foothills. Willakenzie soils are 20 to 40 inches deep to a paralithic contact and occur on low hills.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderately slow permeability. An apparent water table is at its uppermost limit from December through March.
USE AND VEGETATION: Most of these soils have been cleared and are used for production of small grains, hay, pasture, vineyards, Christmas trees, woodlots, homesites, and wildlife habitat. Native vegetation is Douglas fir, grand fir, ponderosa pine, Oregon white oak, Pacific madrone, western swordfern, California hazel, common snowberry, brackenfern, blackberry, Pacific poison oak and grasses.
DISTRIBUTION AND EXTENT: Low hills and foothills along the margins of the Willamette Valley, Oregon; MLRA 2. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Benton County, Oregon, 2004. The source of the name is the abandoned post office of Wellsdale, which was located immediately east of the former Camp Adair military facility along the Southern Pacific railroad tracks north of Corvallis in Benton County.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the soil surface to a depth of 24 inches (A1, A2, BA horizons)
Argillic horizon - from a depth of 24 to 65 inches (Bt1, Bt2 and BCt horizons)
Aquultic feature - redox depletions with chroma of 2 or less within 75 cm of the mineral soil surface and base saturation (sum of cations) of less than 75 percent in one or more subhorizons within the upper 75 cm of the argillic horizon (Bt1 horizon)
Particle-size control section - from depths of 24 to 44 inches (Bt1, and part of the Bt2 horizon)
This soil was previously recognized as the Veneta Series, Loamy Subsoil Variant in the Benton County Area Soil Survey report. Field observations and documentation from several counties in the MLRA 2 Willamette Valley update area indicate the Wellsdale soils occur more extensively than was previously recognized. Wellsdale soils occur on the Dolph and Brateng geomorphic surfaces.
Depths to diagnostic horizons and features start from the mineral soil surface.
Due to further field investigations, the type location for the series has been moved to Yamhill County, Oregon to reflect the current central concept.
Classification revised 01/2002 to reflect active mineralogy.
This revision is based on extensive lab data on Wellsdale and associated Willakenzie series on the same geology.
ADDITIONAL DATA: Characterization data of 5 pedons from the National Soil Survey Lab with User Pedon ID #s: 62OR071009, 62OR071010, 01OR071005, 01OR071006, 01OR071012, 01OR071013, and 01OR071014.