LOCATION CULBERTSON OR
Established Series
Rev. DFA/AON
06/2011
CULBERTSON SERIES
The Culbertson series consists of very deep and deep, well drained soils that formed in volcanic ash and loess mixed with colluvium from andesite. These soils are on slopes of 0 to 50 percent. The mean annual precipitation is about 40 inches and the mean annual air temperature is about 49 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Humixerepts
TYPICAL PEDON: Culbertson loam, woodland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 5 inches, dark brown (7.5YR 3/3) loam, brown (7.5YR 5/3) dry; moderate very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 10 percent shot 2-5mm. in diameter; slightly acid (pH 6.2); clear wavy boundary. (4 to 8 inches thick)
A2--5 to 12 inches, dark reddish brown (5YR 3/3) loam, brown (7.5YR 5/3) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 10 percent shot 2-5mm. in diameter; slightly acid (pH 6.2); clear wavy boundary. (5 to 10 inches thick)
BA--12 to 22 inches; dark reddish brown (5YR 3/4) loam, brown (7.5YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular pores; 5 percent shot 2-5 mm. in diameter; slightly acid (pH 6.4); clear wavy boundary. (6 to 12 inches thick)
Bw--22 to 41 inches, reddish brown (5YR 4/4) clay loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; slightly acid (pH 6.4); gradual wavy boundary. (19 to 24 inches thick)
C--41 to 60 inches; reddish brown (5YR 4/4) loam, brown (7.5YR 5/4) dry; massive; hard, firm, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; slightly acid (pH 6.4).
TYPE LOCATION: Hood River County, Oregon; NE1/4 SE1/4 SE1/4 sec. 3, T.1N., R.10E.
RANGE IN CHARACTERISTICS: The soils are usually moist, but are dry for 60 to 80 consecutive days within the 3 months following the summer solstice in all subhorizons between depths of 4 and 12 inches. The mean annual soil temperature is 49 to 53 degrees F. Depth to bedrock is 40 to 60 inches or more. The umbric epipedon is 10 to 18 inches thick. Rock fragments in the control section range from 0 to 15 percent.
The A horizon has hue of 7.5YR or 5YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It has 5 to 20 percent by volume of shot 2 to 5 mm. in diameter.
The BA and Bw horizon has hue of 7.5YR or 5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is heavy or clay loam with 25 to 32 percent clay. This horizon has moderate fine to medium subangular blocky structure.
COMPETING SERIES: These are the
Bins,
Hullt and
Wadell series. Bins soils have frigid soil temperature. Hullt soils are very strongly acid and lack ash in any part. Wadell soils have more than 15 percent rock fragments in the control section and lack any influence of ash.
GEOGRAPHIC SETTING: The Culbertson soils on slopes of 0 to 50 percent at elevations of 400 to 1,800 feet. They formed in volcanic ash and loess mixed with moderately fine textured colluvium weathered from andesite over andesite or basalt bedrock. Summers are warm and dry with average July temperature of 62 degrees to 65 degrees F. Winters are cool and moist with average January temperature of 31 degrees to 34 degrees F. and a mean annual temperature of 47 degrees to 51 degrees F. Average annual precipitation is 35 to 45 inches. The frost-free period is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Bald, Oak Grove, and
Wyeth soils. Bald soils have steeper slopes and are 20 to 40 inches deep to bedrock. Oak Grove soils have fine-textured argillic horizons. Wyeth soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well-drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Principal use is timber production. Other used include grazing and wildlife. Native vegetation is mainly Douglas-fir, chinquapin, maple, willow and bunchgrasses.
DISTRIBUTION AND EXTENT: Uplands of north-central Oregon; MLRA 6. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Hood River County, Oregon, 1975.
National Cooperative Soil Survey
U.S.A.