LOCATION WAUNA OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, acid, mesic Fluvaquentic Endoaquepts
TYPICAL PEDON: Wauna silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark gray (10YR 3/1) silt loam, light brownish gray (10YR 6/2) dry; moderate very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; very strongly acid (pH 4.8); abrupt clear boundary. (6 to 10 inches thick)
Bg--8 to 26 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; many medium distinct strong brown (7.5YR 4/6) redox concentrations; weak coarse prismatic structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores with common, 3 millimeter, vertical tubular pores; strongly acid (pH 5.4); abrupt smooth boundary. (10 to 20 inches thick)
Cg--26 to 60 inches; dark grayish brown (2.5Y 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; common medium prominent strong brown (7.5YR 4/6) redox concentrations; massive; hard, friable, slightly sticky and slightly plastic; common fine roots; many fine tubular and common, 3 millimeters, vertical tubular pores; strongly acid (pH 5.2).
TYPE LOCATION: Columbia County, Oregon; 100 feet north of county road in the SW corner of sec. 21, T. 8 N., R. 4 W.
RANGE IN CHARACTERISTICS: The soil is saturated with water in some part throughout the year and is subject to fresh water overflow during spring floods and high tides unless diked and artificially drained. They have an irregular decrease in organic matter. The mean annual soil temperature ranges from 53 to 55 degrees F. The particle-size control section is 18 to 35 percent clay with less than 15 percent coarser than very fine sand.
The A horizon has value of 2 or 3 moist, 5 or 6 dry, and chroma of 1 or 2 dry and moist. A thin overwash of sand or fine sand less than 4 inches thick overlies this horizon in some areas.
The Bg horizon has value of 4 or 5 moist and chroma of 1 or 2 moist. It has distinct to prominent mottles. It is a silt loam or silty clay loam with 18 to 35 percent clay. In some pedons, this horizon has thin lenses of peaty material with moist value of 2 or 3 and moist chroma of 1 in the 10YR hue.
The Cg horizon has hue of 10YR, 2.5Y or neutral, value of 4 or 5 moist and chroma of 2 or 3 moist. It is composed of stratified material ranging from silt loam to sandy loam. Redox concentrations are distinct or prominent with some areas having dark brown (7.5YR 3/2) hardened pore surfaces up to 1/4 inch in diameter formed in tubular pores and channels. Thin layers of gray (10YR 6/1) ash-like material are in some pedons. Peat or muck lenses are below 60 inches in some pedons.
COMPETING SERIES: These are the Elkins and Zepernick series. Elkins soils meet the humic subgroup criteria in that the Ap horizon has moist value of 3 and dry value of 5. Elkins soils formed in acid alluvium from sedimentary rocks. Zepernick sils have a solum thickness of 30 to 65 inches and formed in alluvium from Wisconsin age till.
GEOGRAPHIC SETTING: Wauna soils are on flood plains. Slopes are 0 to 3 percent. The soils formed in recent alluvium mixed with some volcanic ash. They are at elevations of 10 to 20 feet in a climate with warm moist summers and cool wet winters. The mean annual precipitation is 50 to 80 inches. Mean July temperature is 62 to 68 degrees F, mean January temperature is 36 to 40 degrees F, and mean annual temperature is 50 to 54 degrees F. The frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Locoda and Crims soils. Locoda soils have chroma of 1 or less throughout with redox features to the surface. Crims soils are organic soils.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: When diked and drained, the soils are used for improved pasture and truck crops. Areas outside of dike are in native vegetation and are used for pasture and wildlife habitat. The native vegetation is ash, willow, cottonwood, grasses, forbs and tussocks (Juncus Sp.).
DISTRIBUTION AND EXTENT: Northwestern Oregon along the Columbia River. The soil is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Columbia County, Oregon, 1983.
REMARKS: Diagnostic horizons and other features:
Ochric epipedon
Cambic horizon 8 to 26 inches