LOCATION PADIGAN OREstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Xeric Endoaquerts
TYPICAL PEDON: Padigan clay, in a cultivated area. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; very dark gray (2.5Y N3/) clay, very dark gray (2.5Y N3/) dry; strong fine medium granular structure; extremely hard, firm, very sticky and very plastic; many very fine roots; many fine irregular pores; mildly alkaline (pH 7.4); abrupt smooth boundary. (5 to 8 inches thick)
A--6 to 12 inches; very dark gray (2.5Y N3/) clay, very dark gray (2.5Y N3/) dry; moderate very coarse prismatic structure; extremely hard, firm, very sticky and very plastic; common fine roots; many very fine irregular pores; mildly alkaline (pH 7.6); clear wavy boundary. (5 to 8 inches thick)
Bkss1--12 to 25 inches; very dark gray (2.5Y N3/) clay, very dark gray (2.5Y N3/) dry; moderate very coarse prismatic structure parting to strong medium angular blocky; extremely hard, firm, very sticky and very plastic; many prominent intersecting slickensides; common fine roots; common very fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (11 to 15 inches thick)
Bkss2--25 to 36 inches; very dark grayish brown (2.5Y 3/2) clay, dark grayish brown (2.5Y 4/2) dry; moderate very coarse prismatic structure parting to strong medium angular blocky; extremely hard, firm, very sticky and very plastic; many prominent intersecting slickensides; common fine roots; common very fine tubular pores; common fine distinct masses of iron accumulation; soft accumulations of light gray (10YR 7/2) carbonates which are violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (9 to 13 inches thick)
Bkss3--36 to 42 inches; grayish brown (2.5Y 5/2) clay, light gray (2.5Y 7/2) dry; massive; extremely hard, firm, very sticky and very plastic; many prominent intersecting slickensides; common fine roots; few very fine tubular pores; common fine distinct masses of iron accumulation; soft accumulations of light gray (10YR 7/2) carbonates which are violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (5 to 8 inches thick)
2Bk--42 to 60 inches; grayish brown (2.5Y 5/2) gravelly sandy clay loam, light gray (2.5Y 7/2) dry; massive; hard, friable, sticky and plastic; few fine roots; few fine irregular pores; common fine distinct masses of iron accumulation; 20 percent gravel; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Jackson County, Oregon; about 2 miles north of Medford; approximately 1,950 feet east and 850 feet north of the southwest corner of sec. 32, T. 36 S, R. 1 W.
RANGE IN CHARACTERISTICS: The soil is usually moist but it is dry between 4 and 12 inches for 60 to 80 consecutive days in the four month period following the summer solstice. The soil profile has cracks that open and close once each year. Slickensides are close enough to intersect in all or some part between 10 and 40 inches. The mean annual soil temperature is 47 to 56 degrees F. Depth to bedrock is 60 or more inches. The particle-size control section is 60 to 70 percent clay, 0 to 10 percent gravel and 0 to 5 percent cobbles. Soft accumulations of carbonates are below a depth of 20 inches. Depth to the 2Bk horizon, when present, is over 40 inches and has 15 to 25 percent gravel and 0 to 5 percent cobbles.
The A horizon has hue of 10YR or 2.5Y, values of 3 or less moist and 3 or 4 dry, and has chroma of 1 or less both moist and dry.
The Bkss horizon is clay with hue of 2.5Y or 10YR, chroma of 1 or less where distinct mottling and lime concretions are absent. The chroma ranges to 3 where mottling is distinct.
COMPETING SERIES: These are the Bashaw, Coker, and Natroy series. Bashaw soils are moderately acid to neutral and lack carbonates. Coker soils are dry for 80 to 110 consecutive days and are somewhat poorly drained. Natroy soils are neutral to strongly acid and lack secondary carbonates.
GEOGRAPHIC SETTING: Padigan soils are on alluvial fans and basins at elevations of 1,200 to 4,000 feet. Slopes are 0 to 3 percent. The soils formed in clayey alluvium weathered from tuffs, breccias, and andesite. The mean annual precipitation is 18 to 30 inches. The mean annual temperature is 46 to 54 degrees F. The frost-free period is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carney, Cove, Heppsie, McNull, and Medco soils and the competing Coker soils. Carney soils are less than 40 inches deep to bedrock. Cove, Heppsie, McNull, and Medco soils lack intersecting slickensides.
DRAINAGE AND PERMEABILITY: Poorly drained, very slow permeability. A water table is at 1 foot above to 0.5 feet below the surface from November to May.
USE AND VEGETATION: These soils are used for hay, irrigated pasture, and grazing. Native vegetation is grasses, rushes, and sedges.
DISTRIBUTION AND EXTENT: Southwestern Oregon; MLRA 5. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988.
REMARKS: The classification was changed from Typic Pelloxererts to Xeric Endoaquerts in 5/94.
Diagnostic features recognized in this pedon:
Aquerts feature - the zone from 0 to 60 inches having aquic conditions for sometime in most years. The zone from 0 to 25 inches having chroma of 1 or less and from 25 to 60 inches having chroma of 3 or less with distinct redox concentrations.
Endosaturation