LOCATION DUFUR              OR
Established Series
Rev. GLG/TAD/AON
10/2002

DUFUR SERIES


The Dufur series consists of deep, well-drained soils that formed in reworked loess and ash, and colluvium and alluvium weathered from sedimentary bedrock. These soils are on uplands and have nearly level to steep slopes. The mean annual precipitation is about 13 inches and the mean annual air temperature is about 49 degrees F.

SOIL FAMILY: Coarse-loamy, mixed, mesic Calcic Haploxerolls.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Calcic Haploxerolls

TYPICAL PEDON: Dufur silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)

Ap1--0 to 6 inches; very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; slightly acid (pH 6.5) abrupt smooth boundary. (6 to 9 inches thick)

Ap2--6 to 8 inches; very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium platy structure; hard, firm, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (0 to 2 inches thick)

B1--8 to 12 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; about 3 percent rock fragments 2 mm. to 1 inch in diameter; 5 percent very firm noncalcareous nodules 1/4 to 3/4 inches in diameter; neutral (pH 6.7); clear wavy boundary. (0 to 7 inches thick)

B21--12 to 18 inches; dark brown (10YR 4/3) silt loam, brown (10YR 5/3) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; 3 percent rock fragments, 2 mm. to 1 inch in diameter; 5 percent very firm noncalcareous nodules 1/4 to 3/4 inches in diameter; neutral (pH 7.0); gradual smooth boundary. (4 to 8 inches thick)

B22--18 to 22 inches; dark brown (10YR 4/3) silt loam, brown (10YR 5/3) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; about 5 percent rock fragments 2 mm. to 1 inch in diameter; 5 to 10 percent very firm noncalcareous nodules 1/4 to 3/4 inches in diameter; mildly alkaline (pH 7.4); gradual smooth boundary. (10 to 20 inches thick)

B3--32 to 42 inches; dark yellowish brown (10YR 4/4) silt loam, yellowish brown (10YR 5/4) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; 2 percent rock fragments 2 mm. to 1 inch in diameter; 5 percent very firm noncalcareous nodules 1/4 to 3/4 inches in diameter; mildly alkaline (pH 7.7); clear smooth boundary. (5 to 15 inches thick)

IIC1ca--42 to 61 inches; yellowish brown (10YR 4/4) silt loam, yellowish brown (10YR 6/4) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; 2 percent rock fragments 2 mm. to 1 inch in diameter; 5 percent very firm noncalcareous nodules 1/4 to 3/4 inches in diameter; mildly alkaline (pH 7.7); clear smooth boundary. (5 to 15 inches thick)

IIIC2r--61 inches; semiconsolidated sedimentary bedrock.

TYPE LOCATION: Wasco County, Oregon; 2 miles north of Dufur; 250 feet northeast of road on broad ridgetop in the NW1/4 SW1/4 NW1/4 sec. 13, T.1S., R.13E.

RANGE IN CHARACTERISTICS: In most years the soils is usually moist but is dry throughout the control section for 80 to 90 consecutive days within the 4 month period following the summer solstice. The mean annual soil temperature ranges from 50 degrees to 52 degrees F. Depth to bedrock ranges from40 to 60 inches or more. The solum ranges from 30 to 50 inches thick. Depth to secondary lime ranges from 30 to 43 inches. Rock fragments up to about 1 inch in diameter range from 0 to 5 percent in the A and B horizons.

The A horizon has value of 2 or 3 moist. It is silt loam or loam.

The B horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4 dry and moist. It is silt loam or loam with 12 to 18 percent clay and 18 to 22 percent sand fragments coarser than very fine sand. The B horizon has up to 10 percent noncalcareous nodules 1/4 to 3/4 inch in diameter. The B3 horizon is weakly calcareous in some pedons.

COMPETING SERIES: These are the Chard, Disautel, Kidman, Marriott, Molcal, Tammany Creek and Timentwa series. Chard soils have moderately coarse textures within the control section and are underlain by coarse sand. Disautel soils have more than 15 percent rock fragments in the control section and have hard glacial till at depths of less than 40 inches. Kidman soils are moderately and strongly alkaline, have 7.5YR hue and have fine sandy loam and light loam B horizons. Marriott soils average fine sandy loam and have 20 to 35 percent rock fragments in the texture control section. Molcal soils are strongly alkaline in some part and calcareous throughout the profile or below depth of 10 inches. Tammany Creek soils have in some part and calcareous throughout the profile or below depth of 10 inches. Tammany Creek soils have 5 to 35 percent rock fragments. Timentwa soils have 15 to 50 percent rock fragments in the B2 horizons overlying extremely hard glacial till.

GEOGRAPHIC SETTING: Dufur soils have nearly level to steep slopes with gradients up to 40 percent and are on uplands at elevations of 800 to 1,800 feet. The soils formed in a reworded loess mantle with an appreciable component of volcanic ash over mixed alluvium and colluvium and sedimentary bedrock. Summers are warm and dry. Winters are cool and moist. The mean annual temperature is 48 degrees to 50 degrees F. Precipitation ranges from 12 to 14 inches annually. Frost-free period (32 degrees F.) is 120 to 150 days and (28 degrees F.) 150 to 200 days.

ASSOCIATED SOILS: These are the Duart, Nansene and Walla Walla soils. Duart soils are 20 to 40 inches deep to a paralithic contact. Nansene soils are on very steep north-facing slopes, are coarse-silty and have mollic epipedons thicker than 20 inches. Walla Walla soils are coarse-silty and lack secondary lime above depth of 43 inches.

DRAINAGE AND PERMEABILITY: Well-drained; slow to rapid runoff; moderate permeability.

USE AND VEGETATION: Principal use is for grain crops. Other uses include hay and pasture and native range. Native vegetation is mainly bluebunch wheatgrass, Sandberg bluegrass and forbs such as yarrow, phlox, buckwheat and balsamroot.

DISTRIBUTION AND EXTENT: North-central Oregon. The soils are inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Wasco County, Oregon, 1975.

ADDITIONAL DATA: Laboratory data on 2 profiles (S57-Oreg-33-6) and (S57-Oreg-33-7) in Field and Laboratory Data of Soils in Wasco, Sherman and Gilliam Counties, Oregon, by the S.C.S. Soil Survey Laboratory, Riverside, California, May, 1959.


National Cooperative Soil Survey
U. S. A.