LOCATION RICKREALL OREstablished Series
TAXONOMIC CLASS: Clayey, mixed, active, mesic, shallow Xeric Haplohumults
TYPICAL PEDON: Rickreall silty clay loam, oak and grass. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 5 inches; dark reddish brown (5YR 5/3) silty clay loam, reddish brown (7.5YR 5/4) dry; weak medium and coarse subangular blocky structure; slightly hard, firm, sticky and slightly plastic; many fine and very fine roots; many very fine irregular pores; strongly acid (pH 5.4); clear smooth boundary. (3 to 6 inches thick)
B1--5 to 8 inches; dark reddish brown (5YR 3/4) silty clay, reddish brown (5YR 4/4) dry; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; many very fine and fine roots; many very fine and fine tubular pores; strongly acid (pH 5.2); clear smooth boundary. (2 to 3 inches thick)
B21t--8 to 12 inches; reddish brown (5YR 4/4) clay, reddish brown (5YR 5/4) dry; moderate fine and medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common very fine roots; many very fine and fine tubular pores; few thin and moderately thick clay films on peds and in pores; strongly acid (pH 5.2); clear smooth boundary. (3 to 5 inches thick)
B22t--12 to 17 inches; yellowish red (5YR 4/6) clay, yellowish red (5YR 5/6) dry; moderate medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common fine roots; many very fine tubular pores; common moderately thick clay films; 15 percent yellowish brown weathered pebbles; very strongly acid (pH 5.0); abrupt wavy boundary. (4 to 6 inches thick)
Cr--17 to 19 inches; fractured partially weathered siltstone with a few tongues of the B22t horizon extending into fractures; many thick yellowish red (5YR 4/6) clay films on fragments.
TYPE LOCATION: Polk County, Oregon; 2.3 miles southwest of Dallas; in the NE1/4 SE1/4 section 12, T. 8 S., R. 6 W.
RANGE IN CHARACTERISTICS: The profiles are usually moist but are dry in all parts for 45 consecutive days or more within the 3-month period following the summer solstice in more than 6 years out of 10. The mean annual soil temperature ranges from 53 to 55 degrees F. The thickness of the solum and depth to a paralithic contact range from 12 to 20 inches. Rock fragments of weathered sedimentary rock range from few to 35 percent in the control section, the amount increasing with depth.
The A horizon has hue of 7.5YR through 5YR, value of 2 through 4 moist, 3 through 5 dry, and chroma of 2 through 4 moist, 3 or 4 dry. It has strong or moderate granular or moderate or weak subangular blocky structure.
The Bt horizon has hue of 7.5YR through 2.5YR, value of 3 or 4 moist, 4 or 5 dry and chroma of 4 through 6 moist and dry. It ranges from silty clay to clay and has 40 to 50 percent clay. This horizon has strong or moderate fine to medium subangular blocky structure. The clay films range from few thin to common or many moderately thick.
COMPETING SERIES: These are the Bellpine, Chehulpum, Nekia, Philomath and Witzel series. Bellpine soils have a paralithic contact at depths of 20 to 40 inches. Chehulpum soils have 18 to 35 percent clay. Nekia soils have a hue of 10YR and lack a Bt horizon. Witzel soils have a lithic contact and have more than 35 percent rock fragments in the series control section.
GEOGRAPHIC SETTING: The Rickreall soils are on gentle smooth ridges to steep foothills and uplands of the Coast Range at elevations of 300 to 800 feet. The soils formed in fine textured colluvium and residuum weathered from sedimentary bedrock. The winters are cool and moist and the summers are warm and dry. The average January temperature is 39 degrees F. The average July temperature is 67 degrees F. The average annual temperature is 52 to 54 degrees F. The annual precipitation is 40 to 60 inches. The frost-free season is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Bellpine soils and the Dupee, Jory and Willakenzie soils. Dupee soils are moderately well or somewhat poorly drained and are mottled. Jory soils are deeper than 40 inches to a lithic or paralithic contact. Willakenzie soils are 20 to 40 inches deep to a paralithic contact and have 27 to 35 percent clay.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used for pasture, recreation, water supply and wildlife. The vegetation is Oregon white oak, wild rose, poison-oak, brackenfern, snowberry and grasses.
DISTRIBUTION AND EXTENT: These soils are on the low foothills of the Coast Range. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Polk County, Oregon, 1977.