LOCATION DEFENBAUGH OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Haplocambids
TYPICAL PEDON: Defenbaugh loam on a 2 percent slope, rangeland. (Colors are for moist soil unless otherwise noted.)
A--0 to 5 inches; pale brown (10YR 6/3) loam, dark brown (10YR 3/3) moist; moderate medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; many medium and fine vesicular pores; slightly effervescent-disseminated lime; 5 percent gravel; moderately alkaline (pH 8.4); clear smooth boundary. (3 to 7 inches thick)
Bk--5 to 16 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; many very fine vesicular and irregular pores; slightly effervescent-lime segregated in few fine threads; moderately alkaline (pH 8.3); clear smooth boundary. (8 to 24 inches thick)
Bq--16 to 29 inches; yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; many very fine vesicular and irregular pores; 5 percent durinodes; slightly alkaline (pH 7.5); clear smooth boundary. (11 to 16 inches thick)
2BC--29 to 47 inches; light yellowish brown (10YR 6/4) very fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many fine roots; many very fine irregular pores; mildly alkaline (pH 7.4); clear smooth boundary. (13 to 19 inches)
2C1--47 to 53 inches; yellowish brown (10YR 5/4) sandy loam, dark yellowish brown (10YR 3/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; common fine roots; many very fine and fine irregular pores; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 12 inches thick)
2C2--53 to 60 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine pores; many very fine and fine irregular pores; moderately alkaline (pH 8.0).
TYPE LOCATION: Harney County, Oregon; about 2 miles northeast of Fields in the SW1/4SW1/4 section 33, T. 37 S., R. 33 E.
RANGE OF CHARACTERISTICS: The soils are dry for more than three-fourths of the time when the soil temperature is greater than 41 degrees F. The soil temperature is above 41 degrees F. from about March 15 to about November 15. The soil is dry between 8 and 21 inches from about May 15 to November 15. The mean annual soil temperature is 47 to 50 degrees F. The particle-size control section is less than 5 percent gravel and averages 18 to 35 percent clay. Some pedons are laminated below 40 inches. Depth to the lithologic discontinuity is 25 to 45 inches. Hue is 10YR or 7.5YR.
The A horizon has value of 6 or 7 dry, 3 or 4 moist and chroma of 3 or 4 moist and dry. It has 1 to 2 percent organic matter. It has an EC of 2 to 8 mmhos./cm. and an SAR of 1 to 4.
The Bk and Bq horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 moist and dry. It is clay loam or loam with 25 to 30 percent clay. It has 0 to 15 percent durinodes.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Defenbaugh soils are on alluvial fans at elevations of 3,900 to 4,600 feet. Slopes are 0 to 4 percent. The soils formed in alluvium. The climate is characterized by cold dry winters and warm dry summers. The mean annual precipitation is 6 to 10 inches and the mean annual temperature is 45 to 49 degrees F. The frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goldrun, Alvodest, Davey, Deppy, Dixon, Outerkirk, and Tumtum soils. Goldrun soils are sandy throughout and are on sand dunes. Alvodest soils are sodic. Davey soils have a sandy particle-size control section. Deppy soils have a loamy argillic horizon over a strongly cemented duripan. Dixon soils have a fine-loamy over sandy or sandy-skeletal particle-size control section. Outerkirk soils have a coarse-loamy particle-size control section. Tumtum soils have a loamy argillic horizon over a indurated duripan.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability. During periods of rapid snow melt the soils are subject to flooding (rare).
USE AND VEGETATION: The soils are used for rangeland. Vegetation commonly in shadscale, black greasewood, bud sagebrush, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Southeastern Oregon; MLRA 24. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Harney County, Oregon, 1997.
REMARK: Diagnostic horizons and features recognized in this pedon are:
Carbonates in the upper 16 inches of the profile are wind deposited from adjacent playas.
Ochric epipedon
Cambic horizon from 5 to 29 inches