LOCATION PHOENIX OREstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Xeric Epiaquerts
TYPICAL PEDON: Phoenix clay - cultivated (Colors are for moist soil unless otherwise noted.)
Ap--0 to 3 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3.5/1) dry; strong fine granular structure; extremely hard, firm, very sticky and very plastic; common roots; many irregular pores; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 6 inches thick)
Bss1--3 to 20 inches; dark gray (10YR 4/1) clay, dark gray (10YR 4/1) dry; upper 4 inches is massive to cloddy; moderate, coarse and medium angular blocky structure below 4 inches; extremely hard, firm, very sticky and very plastic; many large slickensides; common roots; common very fine tubular pores; slightly acid (pH 6.4); diffuse smooth boundary. (10 to 20 inches thick)
Bss2--20 to 33 inches; dark gray (N 4/) clay, dark gray (N 4/) dry; moderate coarse and medium angular blocky structure; many large slickensides; extremely hard, firm, very sticky and very plastic; common roots; common very fine tubular pores; neutral (pH 7.2); clear smooth boundary. (3 to 17 inches thick)
Bss3--33 to 40 inches; gray (2.5Y 5/1) clay, gray (2.5Y 5/1) dry; moderate coarse and medium angular blocky structure; many large slickensides; extremely hard; firm, very sticky and very plastic; common roots; common very fine tubular pores; mildly alkaline (pH 7.4); abrupt smooth boundary. (6 to 10 inches thick)
2Cr--40 inches; sandstone.
TYPE LOCATION: Jackson County, Oregon; about 4 miles east of Central Point, about 750 feet east of Sticky Lane and 200 feet south of a field road; about 2,400 feet north and 750 feet east of the SW corner of sec. 33, T. 36 S., R. 1 W.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry between 4 and 12 inches for 80 to 110 consecutive days in the 4 months following the summer solstice. The soil profile opens and closes once a year. Slickensides are close enough to intersect in all or in some parts between depths of 10 and 40 inches. The mean annual soil temperature is 52 to 56 degrees F. Depth to soft rock is 20 to 40 inches. The particle-size control section is 60 to 70 percent clay and 0 to 10 percent gravel. Color value moist is 4 or more in the upper 12 inches in more than half of each pedon. Chroma is 1 or less within the upper 20 inches of the solum.
The Ap and Bss1 horizons have hue of 10YR or 2.5Y, value of 3.5 or 4 moist and dry and chroma of 1 moist, 1 or 2 dry.
The Bss2 and Bss3 horizons have hue of 10YR or 2.5Y, value of 4 or 5 moist and dry and chroma of neutral to 2 moist and dry.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Phoenix soils are moderately deep and poorly drained. They formed in alluvium and colluvium from soft rock. They are on fans and have slopes of 0 to 3 percent. Elevation is 1,200 to 1,700 feet. The mean annual precipitation is 18 to 25 inches. The mean annual temperature is 50 to 54 degrees F. The frost-free period is 160 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Agate, Carney and Coker soils. Carney soils have moist values of 3 and chromas of 2 or 3 in the upper 12 inches. Agate soils are fine-loamy and have a duripan at 20 to 40 inches. Coker soils are deep.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow permeability. A perched water table is at a depth of 0 to 0.5 feet from the surface from December to May.
USE AND VEGETATION: These soils are used for irrigated pear orchards, hay, and pasture. Native vegetation is Oregon white oak, poison oak, grasses, sedges and forbs.
DISTRIBUTION AND EXTENT: Southwestern Oregon on valley bottom along lower slopes of Cascade Mountain Range; MLRA 5. The soil is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County, Oregon, 1911.
REMARKS: The classification was changed from Entic Pelloxererts to Xeric Epiaquerts in 5/94.
Diagnostic features recognized in this pedon:
Aquerts feature - the zone from 0 to 20 inches (Ap and Bss1 horizons) having aquic conditions for some time in most years and chroma of 1 or less.
Episaturation - a perched water table at a depth of 40 inches.
Leptic feature - a paralithic contact is at a depth of 40 inches.