LOCATION STAYTON OREstablished Series
TAXONOMIC CLASS: Medial, mixed, mesic Lithic Haploxerands
TYPICAL PEDON: Stayton silt loam - grass. (Colors are for moist soil unless otherwise noted.)
A1--0 to 12 inches; black (5YR 2/1) silt loam, dark reddish brown (5YR 3/3) dry; moderate very fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; many roots; many very fine irregular pores; moderately acid (pH 5.6); gradual wavy boundary. (4 to 14 inches thick)
A2--12 to 15 inches; black (5YR 2/1) silt loam, dark reddish brown (5YR 3/3) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many roots; few fine and common very fine pores; moderately acid (pH 5.8); clear wavy boundary. (0 to 8 inches thick)
AC--15 to 19 inches; dark reddish brown (5YR 3/2) silt loam, reddish brown (5YR 4/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine roots; few medium horizontal pores and common very fine pores; medium acid (pH 5.8); abrupt wavy boundary. (0 to 10 inches thick)
2R--19 inches; basalt bedrock, consolidated.
TYPE LOCATION: Marion County, Oregon; 175 yards north of where Drift Creek crosses Drift Creek Road and about 1 1/2 miles south of Drift Creek Falls; northwest 1/4 southwest 1/4, sec. 17, T. 8 S., R. 1 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 52 to 56 degrees F. The soils are usually moist and have a xeric moisture regime. Depth to bedrock ranges from 12 to 20 inches. The particle-size control section is estimated to have a phosphate retention of 90 to 100 percent, acid oxalate extractable aluminum plus one-half iron of 2.0 to 4.0 percent, and 15-bar moisture of 15 ot 20 percent based on an air-dried sample. The moist bulk density is 0.70 to 0.85 grams per cubic centimeter. Rock fragments are usually absent but some pedons have up to 10 percent gravel. The soils are moderately or strongly acid.
The A horizon has hue of 5YR or 7.5YR, value of 1 or 2 moist, 3 or 4 dry, and chroma of 1 or 2 moist, 2 or 3 dry. It is silt loam and has less than 18 percent clay and less than 15 percent particles coarser than very fine sand. This horizon has weak or moderate granular or very fine or fine subangular blocky structure.
The AC horizon has hue of 5YR or 7.5YR, value of 4 or 5 dry, and chroma of 2 or 3 moist and 3 or 4 dry.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Stayton soils are on gently sloping footslopes and in drainageways at elevations of 250 to 1,200 feet. Slopes are 0 to 7 percent. The soils formed in colluvium mixed with ash or pyroclastic materials over basalt bedrock.. 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 mean January temperature is 39 degrees F, and the mean July temperature is 67 degrees F. The frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jory, Nekia, and Witzel soils. All of these soils lack dominance by amorphous material. Also, Jory and Nekia soils have clayey argillic horizons and the Witzel soils have more than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for pasture, grass seed, recreation, and wildlife habitat. Vegetation is mixed stand of Oregon white oak, vine maple, grasses, and shrubs.
DISTRIBUTION AND EXTENT: Willamette Valley, Oregon; MLRA 2. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Marion County, Oregon, 1973.
REMARKS: This draft represents a change in classification from Medial, mesic Lithic Umbric Vitrandepts based on the Andisol Order.
Diagnostic horizons and features recognized in this pedon:
Umbric epipedon - from surface to 19 inches (A1, A2, and AC horizons)
Lithic contact - 19 inches
Particle-size control section - from 0 to 19 inches having andic soil properties.