LOCATION WALLUSKI OR

Established Series
Rev. JAS/GLG/RWL
06/2011

WALLUSKI SERIES

The Walluski series consists of very deep, moderately well drained soils formed in moderately fine textured alluvium on terraces. Slopes are 0 to 20 percent. The mean annual precipitation is about 85 inches and the mean annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Fine-silty, isotic, isomesic Andic Oxyaquic Humudepts

TYPICAL PEDON: Walluski medial silt loam, forested. (Colors are for moist soil unless otherwise noted.)

Oi--0 to 1 inch; slightly decomposed litter of needles, twigs and leaves.

A--1 to 8 inches; very dark grayish brown (10YR 3/2) medial silt loam, dark grayish brown (10YR 4/2) dry; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine, fine and medium roots; many medium and fine irregular pores; extremely acid (pH 4.4); clear wavy boundary. (5 to 11 inches thick)

AB--8 to 15 inches; very dark grayish brown (10YR 3/2) medial silt loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and fine roots; many very fine tubular pores; extremely acid (pH 4.4); gradual wavy boundary. (0 to 11 inches thick)

Bw1--15 to 22 inches; brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; moderate fine and medium subangular blocky structure; moderately hard, friable, moderately sticky and slightly plastic; many fine and medium roots; common very fine tubular pores; extremely acid (pH 4.4); clear wavy boundary. (7 to 14 inches thick)

Bw2--22 to 32 inches; dark yellowish brown (10YR 4/4) silty clay loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine and medium roots; common fine and very fine tubular pores; common fine distinct strong brown (7.5YR 5/6) iron masses; extremely acid (pH 4.2); clear wavy boundary. (9 to 15 inches thick)

Bw3--32 to 48 inches; yellowish brown (10YR 5/4) silty clay loam, light yellowish brown (10YR 6/4) dry; moderate fine prismatic structure; moderately hard, firm, moderately sticky and moderately plastic; few fine and medium roots; common very fine tubular pores; many fine and medium, distinct gray (10YR 6/1) iron depletions, distinct strong brown (7.5YR 5/6) and prominent strong brown (7.5YR 5/8) iron masses; extremely acid (pH 4.2); clear wavy boundary. (0 to 17 inches thick)

2BC--48 to 61 inches; light brownish gray (2.5Y 6/2) clay, light gray (10YR 7/1) dry; weak medium subangular blocky structure; hard, very firm, moderately sticky and moderately plastic; few fine roots; few very fine tubular pores; many medium and coarse faint gray (10YR 5/1) iron depletions and many fine and medium prominent yellowish red (5YR 5/6) and brownish yellow (10YR 6/8) iron masses; extremely acid (pH 4.2)

TYPE LOCATION: Clatsop County, Oregon; about 500 feet west of Lewis and Clark road; SW 1/4 SW 1/4 NW 1/4 section 17, T. 7 N., R. 9 W.

RANGE IN CHARACTERISTICS: The soil is usually moist and is dry for less than 45 consecutive days between the depths of about 4 and 12 inches after the summer solstice. The soils are saturated with water at a depth of 2 to 3 feet during the winter unless artificially drained. The mean annual soil temperature is 47 to 53 degrees F. Depth to iron depletions with chroma of 2 or less is 24 to 40 inches. The difference between the mean winter and mean summer soil temperature varies from 5 to 9 degrees F under canopy cover. The particle-size control section has less than 15 percent coarser than very fine sand and averages less than 35 percent clay. The umbric epipedon is 10 to 20 inches. The upper 5 to 8 inches has an estimated Alox + Feox of 2.0 to 3.0 percent and a moist bulk density of 0.80 to 0.90 g/cc. The lower 5 to 12 inches has an estimated Alox + Feox of 1.0 to 3.0 percent and a moist bulk density of 0.90 to 1.0 g/cc. Andic soil properties, when present, do not extend beyond a depth of 14 inches. It is extremely acid through moderately acid.

The A and AB horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 2 and 3 moist and dry. Texture is medial silt loam. It has 18 to 27 percent clay by field estimate.

The Bw horizon has hue of 10YR or 7.5YR, value of 3 through 5 moist, 5 or 6 dry and chroma of 3 through 5 moist and dry. Texture is silt loam or silty clay loam with 22 to 35 percent clay.

The 2BC or 2C horizon, when present, has hue of 7.5YR through 2.5Y, value of 5 or 6 moist, 6 or 7 dry and chroma of 1 through 8 moist and dry. Texture is silty clay loam, silty clay or clay with 27 to 45 percent clay.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Walluski soils are on Coastal marine and valley terraces at elevations of 20 to 300 feet. Slopes are 0 to 20 percent. The soils formed in moderately fine textured alluvium derived dominantly from sedimentary rock. The climate is characterized by cool wet winters and cool moist summers. The mean annual precipitation is 70 to 100 inches. The mean annual temperature is 47 to 54 degrees F., mean January temperature is 40 degrees F., mean July temperature is 60 degrees F. The frost-free period is 145 to 300 days. The soil is on the Whiskey Run geomorphic surface.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chitwood, Hebo and Knappa series. Chitwood, Hebo and Knappa soils occur on terraces. Chitwood soils are fine textured, somewhat poorly drained and occur on nearly level to concave areas. Hebo soils are fine textured, poorly drained and occur in swales and concave areas. Knappa soils are well drained and have an umbric epipedon 20 to 30 inches thick and occur on nearly level to convex areas.

DRAINAGE AND PERMEABILITY: Moderately well drained; slow to moderate runoff; moderate over slow permeability. An apparent water table is at its uppermost limit from November through May.

USE AND VEGETATION: Most of these soils have been cleared and are dominantly used for forage production and building sites. Other uses include timber production, recreation and wildlife habitat. Native vegetation includes western hemlock, Sitka spruce, Douglas-fir, red alder with an understory of vine maple, salmonberry, red elderberry and western swordfern.

DISTRIBUTION AND EXTENT: Coastal marine and valley terraces of northwest Oregon. MLRA 4A. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Clatsop County, Oregon, 1984.

REMARKS: Diagnostic horizons and features in this pedon:

Umbric epipedon - from 1 to 15 inches (A and AB horizons).
Cambic horizon - from 15 to 48 inches (Bw1, Bw2 & Bw3 horizons).
Andic subgroup feature - from 1 to 15 inches (A and AB horizons) with the zone from 0 to 8 inches qualifying for andic soil properties.
Oxyaquic subgroup feature - saturation above 40 inches for over 20 consecutive days and for over 30 cumulative days.

Classification is based on NSSL data pedon sample number S02OR-007-001 and data collected on associated and similar soils.

All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.

A proposal was submitted to NSSC (2000) to revise the definition of medial to also include those soil properties qualifying for the Andic subgroup under criteria #1 for andic soil properties. If accepted, medial modifiers would be used for those horizons meeting the andic subgroup criteria although not always meeting andic soil properties.

National Cooperative Soil Survey
U.S.A.