LOCATION CHEHALIS WA+OR
Established Series
Rev. JJR/DRU/EED
01/2019
CHEHALIS SERIES
Landscape--river valleys
Landform--flood plains, alluvial terraces
Slope--0 to 10 percent
Parent material--alluvium
Mean annual precipitation--about 1500 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Ultic Haploxerolls
TYPICAL PEDON: Chehalis silt loam in an area of hayland (When described on June 25, 2014, the soil was dry to a depth of 50 cm and moist below that depth.)
Ap1--0 to 13 cm; silt loam, very dark grayish brown (10YR 3/2) moist, brown (10YR 4/3) dry; strong very fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine, common fine, and few medium tubular pores and few medium irregular pores; strongly acid (pH 5.5); abrupt smooth boundary
Ap2--13 to 51 cm; silt loam, very dark grayish brown (10YR 3/2) moist, dark yellowish brown (10YR 4/4) dry; strong very fine subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; many very fine and few fine roots; common very fine and fine tubular pores and few medium irregular pores; faint organic stains on all faces of peds; strongly acid (pH 5.5); abrupt smooth boundary
Bw1--51 to 70 cm; silty clay loam, dark brown (10YR 3/3) moist, dark yellowish brown (10YR 4/4) dry; strong very fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine roots; common very fine and fine tubular pores; faint organic stains on all faces of peds; moderately acid (pH 6.0); clear smooth boundary
Bw2--70 to 123 cm; silty clay loam, dark brown (7.5YR 3/4) moist, brown (7.5YR 4/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few very fine roots; few very fine tubular pores; moderately acid (pH 6.0); abrupt smooth boundary
Bw3--123 to 150 cm; loam, dark yellowish brown (10YR 3/4) moist, dark yellowish brown (10YR 4/4) dry; weak very fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; few very fine tubular pores; slightly acid (pH 6.3)
TYPE LOCATION: Grays Harbor County, Washington, about 4.5 km south of Porter and about 40 m east of South Bank Road; about 355 m north and 125 m east of the southwest corner of section. 3, T. 16 N., R. 5 W., Willamette Meridian; Malone, Washington, U.S. Geological Survey quadrangle; latitude 46.8988883 degrees north, longitude 123.3073867 degrees west, WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--10 to 13 degrees C
Soil moisture control section--dry 45 to 60 days following summer solstice
Mollic epipedon thickness--50 to 150 cm or more
Depth to ultic feature (base saturation sum of 75 percent or less)--25 to 75 cm
Total rock fragment content--0 to 5 percent gravel
Particle-size control section--18 to 35 percent clay (weighted average); less than 15 percent sand
Ap horizon
Hue--2.5Y to 7.5YR
Value--2 to 3 moist, 3 to 5 dry
Chroma--2 or 3 moist, 2 to 4 dry
Fine-earth texture--silt loam, silty clay loam
Reaction (pH)--5.1 to 6.5
Combined thickness--15 to 90 cm
Bw1 and Bw2 horizons
Hue--2.5Y to 7.5YR
Value--2 to 4 moist, 3 to 6 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--silty clay loam, silt loam
Reaction (pH)--5.1 to 6.5
Combined thickness--20 to 135 cm
Bw3 horizon
Hue--2.5Y to 7.5YR
Value--3 or 4 moist, 3 to 6 dry
Chroma--2 to 4 moist, 3 to 6 dry
Fine-earth texture--silt loam, silty clay loam, loam, clay loam, fine sandy loam
Reaction (pH)--5.6 to 6.5
Thickness--20 to 30 cm
C horizon (where present)
Hue--10YR, 2.5Y
Value--3 or 4 moist, 4 to 6 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--silt loam, silty clay loam, loam, fine sandy loam, very fine sandy loam; some horizons may be stratified
Reaction (pH)--5.6 to 7.3
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--5 to 500 m
Mean annual precipitation--760 to 1800 mm
Mean annual air temperature--10 to 13 degrees C
Frost-free period--150 to 235 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Abiqua--greater than 35 percent clay in particle-size control section; on alluvial fans and terraces
Camas--greater than 35 percent rock fragments in particle-size control section; on bars
Chapman--greater than 15 percent sand in particle-size control section; on flood plains higher on the landscape
Clato--less than 18 percent clay in particle-size control section; no mollic epipedon; in similar positions and landforms
Cloquato--less than 18 percent clay in particle-size control section; in convex to linear positions of similar landforms
Eld--greater than 15 percent sand in particle-size control section; in similar positions and landforms
Elma--less than 10 percent clay in lower part of particle-size control section; on convex natural levees and alluvial terraces
Godfrey,
Reed,
Rennie,
Roundtree,
Waldo,
Wapato--aquic conditions to the soil surface; in depressions, oxbows, backswamps, and other concave positions of flood plains
Maytown, McBee--aquic conditions at a depth of 50 to 75 cm from the soil surface; on flood plains
Newberg,
Scatter--less than 18 percent clay and greater than 15 percent sand in particle-size control section; on convex natural levees, alluvial terraces, and flood plains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Depth to apparent seasonal water table--120 to 200 cm or more at times in December through March
Flooding--occasional, brief periods in November through April
Saturated hydraulic conductivity (Ksat)--moderately high or high throughout
USE AND VEGETATION:
Use--crop production, hay production, and livestock grazing in cleared areas; wildlife habitat
Native vegetation--Douglas-fir, red alder, western redcedar, bigleaf maple, black cottonwood, Oregon white oak, vine maple, beaked hazelnut, Cascade Oregon grape, Indian plum, salmonberry, common snowberry, trailing blackberry, western swordfern, western brackenfern, wild ginger, violet, western rattlesnake plantain
DISTRIBUTION AND EXTENT: Western Washington and Oregon; MLRA 2; moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Western Puget Sound Basin, Washington; 1910
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 25 to 100 cm
*Mollic epipedon--zone from the surface to a depth of 70 cm
*Cambic horizon--zone from 70 to 150 cm
11/2016--Type location moved based on field investigations in support of update work. The official series description was edited according to SSR01 Technical Note--Content and Format of Official Series Descriptions (revised 12/2015).
6/1998--Previously classified as fine-silty, mixed, mesic Cumulic Ultic Haploxerolls; classification change based on establishment of CEC activity classes in Soil Taxonomy.
ADDITIONAL DATA: Characterization data--pedon numbers S91OR-047-001 and S72WA-021-007
National Cooperative Soil Survey
U.S.A.