LOCATION SIMCOE WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argixerolls
TYPICAL PEDON: Simcoe silt loam, pasture. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 8 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; neutral (pH 7.0); abrupt smooth boundary. (3 to 14 inches thick)
B21t--8 to 14 inches; grayish brown (10YR 5/2) heavy silt loam, very dark grayish brown (10YR 3/2) moist; moderate coarse prismatic structure; hard, friable, sticky and plastic; common fine roots; common fine tubular pores; few thin to moderately thick clay films on faces of peds; neutral (pH 7.0); gradual wavy boundary. (4 to 10 inches thick)
B22t--14 to 25 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure; hard, firm, sticky and plastic; few fine roots; common fine tubular pores; thin clay films on faces of peds and in pores; neutral (pH 7.0); gradual wavy boundary. (8 to 20 inches thick)
B3t--25 to 37 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; massive; hard, firm, very sticky and very plastic; few fine roots; few fine tubular pores; few thin clay films in pores; neutral (pH 6.8); abrupt wavy boundary. (0 to 18 inches thick)
R--37 inches; unweathered basalt.
TYPE LOCATION: Yakima County, Washington; 2,000 feet north of Highway 3B and 200 feet east of Toppenish Lateral canal, NW1/4 NE1/4 SE1/4 of section 15, T.10N., R.16E., WM.
RANGE IN CHARACTERISTICS: Depth to basalt ranges from 20 to 40 inches. The mean annual soil temperature at a depth of 20 inches ranges from 48 to 54 degrees F. The mollic epipedon ranges from 10 to 20 inches thick. The argillic horizon averages 25 to 35 percent clay and more than 15 percent particles coarser than very fine sand. The particle size control section averages 0 to 15 percent coarse fragments.
The Ap and A1 horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 moist and 2, 3 or 4 dry. It has weak or moderate structure.
The B2t horizon has hue of 10YR or 7.5YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 2 through 4. It is heavy silt loam, clay loam or silty clay loam, and has weak to moderate blocky or prismatic structure and thin to moderately thick clay films on faces of peds and in pores. It is neutral or mildly alkaline.
The B3 or C horizons have hue of 10YR through 5YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 3 through 6 moist and dry. They are clay loam, and may be gravely or cobbly below a depth of 35 inches. It is neutral or mildly alkaline.
COMPETING SERIES: These are the Bissell, Bjork, Cowiche, Galeppi, Margerum, Orr, Ralls, and Springmeyer series. Bissell, Cowiche, Galeppi, Margerum, Orr, Ralls, and Springmeyer soils are more than 40 inches deep. Bjork soils are mildly alkaline in the B2t horizon, have schist or gneiss rock fragments in the particle size control section and are underlain by schist or gneiss at a depth of 20 to 40 inches. Dodes soils have a paralithic contact at a depth of 20 to 40 inches. Indiano soils have 15 to 35 percent rhyolitic or altered volcanic rock fragments in the particle size control section.
GEOGRAPHIC SETTING: Simcoe soils are on uplands at elevations of 1,000 to 2,300 feet. Slopes are 0 to 30 percent. These soils formed in weathered basalt, loess, and minor amounts of volcanic ash. They are in a climate with 8 to 12 inches mean annual precipitation. The mean annual temperature is 47 to 52 degrees F. The frost free season is 120 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Rock Creek soils. Rock Creek soils are less than 20 inches deep over basalt.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: Range, irrigated cropland, and pasture, and for wildlife habitat. Native vegetation is bluebunch wheatgrass, Idaho fescue, big sagebrush, antelope bitterbrush, cheatgrass, balsamroot, and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: South central Washington.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon