LOCATION HARDSCRABBLE OREstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Aquic Palexeralfs
TYPICAL PEDON: Hardscrabble silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) silt loam, pale brown (10YR 6/3) dry; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; medium acid (pH 5.6); abrupt smooth boundary. (5 to 9 inches thick)
BA--8 to 14 inches; dark brown (10YR 4/3) silty clay loam, very pale brown (10YR 7/3) dry; moderate medium subangular blocky structure; slightly hard, firm, sticky and plastic; common very fine roots; many very fine tubular pores; very strongly acid (pH 5.0); abrupt wavy boundary. (5 to 15 inches thick)
2Bt1--14 to 24 inches; brown (10YR 5/3) clay, very pale brown (10YR 7/3) dry; common fine distinct yellowish brown (10YR 5/6) mottles; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; common very fine roots; common very fine tubular pores; common moderately thick clay films; very strongly acid (pH 4.8); clear wavy boundary. (5 to 15 inches thick)
2Bt2--24 to 33 inches; brown (10YR 5/3) clay, very pale brown (10YR 7/3) dry; common fine distinct yellowish brown (10YR 5/6) and light brownish gray (10YR 6/2) mottles; weak coarse prismatic and weak coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; common moderately thick clay films; very strongly acid (pH 4.8); clear wavy boundary. (5 to 15 inches thick)
2BC--33 to 60 inches; brown (10YR 5/3) clay; very pale brown (10YR 7/3) dry; dark gray (10YR 4/1) coatings; common fine distinct yellowish brown (10YR 5/6) and light brownish gray (10YR 6/2) mottles; moderate coarse angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; very strongly acid (pH 4.8).
TYPE LOCATION: Clackamas County, Oregon; 3 miles east of Canby; 1700 feet south and 650 feet west of the NE corner of section 1, T. 4 S., R. 1 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 52 to 56 degrees F. The soil is usually moist but is dry for 45 to 70 consecutive days between depths of 4 and 12 inches during the summer. The solum is 35 to 60 inches thick. Depth to bedrock is more than 60 inches. Depth to the clayey 2Bt argillic horizon is 12 to 24 inches. The increase in clay from the BA horizon to the 2Bt1 horizon is 20 to 30 percent within 1 inch.
The A horizon has hue of 10YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 or 3 moist and dry.
The BA horizon has value of 6 or 7 dry. It is silt loam or silty clay loam, with 25 to 30 percent clay.
The 2Bt horizon has value of 4 or 5 moist, 6 through 8 dry, and chroma of 2 or 3 moist and dry. It is clay or silty clay and averages 50 to 60 percent clay. Rock fragments are weathered and range from 0 to 15 percent gravel or cobbles.
COMPETING SERIES: These are the Bow, Coveland, and Coweeman series. Bow (T) and Coveland soils are neutral or slightly acid with 35 to 50 percent clay in the particle-size control section. Coweeman soils have a hue of 2.5Y in the Bt horizon.
GEOGRAPHIC SETTING: Hardscrabble soils are on uplands at elevations of 150 to 600 feet. Slopes range from 2 to 20 percent. The soils formed in mixed stratified materials. The climate is characterized by cool wet winters and warm dry summers. The mean annual precipitation is 40 to 60 inches. The mean annual temperature is 50 to 54 degrees F. and the frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jory and Saum soils on the uplands and Woodburn, Powell, and Helvetia soils on the adjacent terraces. Jory and Saum soils are well drained and lack mottles. Woodburn and Helvetia have a mollic epipedon and are moderately well drained. Powell soils have a fragipan.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow or medium runoff; very slow permeability.
USE AND VEGETATION: Pasture, hay, and small grains. Native vegetation is Oregon white oak, wild rose, western hazel, blackberry, grasses and widely-spaced Douglas-fir.
DISTRIBUTION AND EXTENT: Northern Willamette Valley in Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES AND EXTENT: Clackamas County, Oregon, 1982.