LOCATION BUCKWILDER OREstablished Series
TAXONOMIC CLASS: Very-fine, smectitic Vertic Argicryolls
TYPICAL PEDON: Buckwilder very cobbly clay loam in rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; grayish brown (10YR 5/2) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular and irregular pores; 25 percent gravel and 20 percent cobbles; slightly acid (pH 6.2); abrupt wavy boundary. (6 to 10 inches thick)
2Bt1--8 to 12 inches; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; strong medium prismatic structure; very hard, very firm, moderately sticky and very plastic; few very fine and fine roots; common very fine tubular and irregular pores; common distinct clay films on faces of peds; 5 percent gravel; neutral (pH 6.8); gradual smooth boundary. (3 to 6 inches thick)
2Bt2--12 to 21 inches; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; strong medium prismatic structure; very hard, very firm, moderately sticky and very plastic; few very fine and fine roots; common very fine tubular and irregular pores; common distinct clay films on faces of peds; 5 percent gravel; neutral (pH 7.2); gradual smooth boundary. (7 to 20 inches thick)
2Btk--21 to 27 inches; dark yellowish brown (10YR 4/4) cobbly clay, brown (10YR 4/3) moist; moderate coarse prismatic structure; very hard, very firm, moderately sticky and very plastic; few very fine roots; common very fine tubular and irregular pores; common distinct clay films on faces of peds; strongly effervescent secondary carbonates on rock fragments; 10 percent gravel and 10 percent cobbles; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 10 inches thick)
2R--27 inches; fractured igneous bedrock; violently effervescent secondary carbonates along bedrock fractures.
TYPE LOCATION: Harney County, Oregon; 1,500 feet south and 1,200 feet west of the northeast corner of sec 12, T. 40 S., R. 34 E.; Van Horn Basin Quadrangle; Lat. 42 degrees 07 minutes 04 seconds N., Long. 118 degrees 40 minutes 00 seconds W., NAD 1927.
RANGE IN CHARACTERISTICS: The soils are moist in the winter and spring and dry in the summer and fall for 45 to 60 consecutive days. The mean annual soil temperature is 42 to 45 degrees F. The mean summer soil temperature is 56 to 59 degrees F. The thickness of the solum and depth to bedrock is 20 to 40 inches. The particle-size control section is 60 to 75 percent clay and 5 to 25 percent rock fragments, mainly as gravel and cobbles. The mollic epipedon is 16 to 30 inches thick and includes the 2Bt horizon. Depth to secondary carbonates is 16 to 30 inches. The linear extensibility of the solum is 6.0 to 8.0 centimeters.
The A horizon has value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3 dry and moist. It is clay loam with 30 to 40 percent clay and 35 to 60 percent rock fragments. It has 2 to 4 percent organic matter. There is an absolute clay increase of 25 to 40 percent between the A and 2Bt horizon.
The 2Bt horizon has value of 4 or 5 dry and chroma of 3 or 4 dry. It is clay with 60 to 75 percent clay. It contains 5 to 15 percent rock fragments. It has 1 to 2 percent organic matter.
The 2Btk horizon has value of 4 or 5 dry, 3 or 4 moist and chroma of 3 or 4 dry and moist. It is clay with 60 to 75 percent clay. It contains 10 to 25 percent rock fragments. It is mildly or moderately alkaline.
COMPETING SERIES: There are no competing series. The Cimarron, Gourley and Winridge series are similar. These soils are in the fine family.
GEOGRAPHIC SETTING: Buckwilder soils occur on mountainsides and tablelands. The soils formed in colluvium and residuum from mixed igneous rock sources. Slopes are 3 to 35 percent. Elevation ranges from 6,000 to 7,200 feet. The climate is cool, semiarid with cold, moist winters and cool dry summers. The mean annual precipitation is 12 to 16 inches. The mean annual temperature is 40 to 43 degrees F. The frost-free period is 30 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baconcamp, Clamp, Duff, Leemorris, and Noname soils. Baconcamp soils are loamy-skeletal and lack an argillic horizon. Clamp soils are loamy-skeletal and shallow. Duff soils are 40 to 60 inches to bedrock, fine-loamy and lack an argillic horizon. Leemorris soils have 40 to 60 percent clay in the particle size control section . Noname soils are shallow, loamy, and have a ochric epipedon.
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; very slow permeability.
USE AND VEGETATION: The soils are used for rangeland and wildlife habitat. Vegetation commonly is Idaho fescue, low sagebrush, bluebunch wheatgrass, Sandberg bluegrass, and Thurber needlegrass.
DISTRIBUTION AND EXTENT: Southeastern Oregon; MLRA 23. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Harney County, Oregon; 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from a depth of 0 to 21 inches (A, 2Bt1, and 2Bt2 horizons)
Argillic horizon - from a depth of 8 to 27 inches (2Bt1, 2Bt2, and 2Btk horizons)
Particle-size control section - from a depth of 8 to 27 inches (2Bt1, 2Bt2,and 2Btk horizons); over 60 percent clay
Xeric soil moisture regime