LOCATION DIXON              OR
Established Series
Rev. RDK/TDT/TM
07/2001

DIXON SERIES


The Dixon series consists of very deep, well drained soils that formed in old alluvium. Dixon soils are on dissected alluvial fans and have slopes fo 0 to 15 percent. The mean annual precipitation is about 8 inches and the mean annual temperature is about 46 degrees F.

TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Xeric Haplocambids

TYPICAL PEDON: Dixon gravelly sandy clay loam on a 7 percent slope, rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches; pale brown (10YR 6/3) gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and fine vesicular and irregular pores; 25 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary. (1 to 4 inches thick)

Bw--2 to 8 inches; light yellowish brown (10YR 6/4) clay loam, dark brown (7.5YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, sticky and plastic; few very fine, fine, medium, and coarse roots; many very fine vesicular and irregular pores; slightly effervescent-disseminated lime; 5 percent gravel; moderately alkaline (pH 8.3); clear smooth boundary. (4 to 8 inches thick)

Bk1--8 to 18 inches; light yellowish brown (10YR 6/4) gravelly sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine, and medium roots; many very fine irregular pores; strongly effervescent-lime segregated in few fine filaments and threads and in few irregularly shaped soft masses; 20 percent gravel; moderately alkaline (pH 8.4); gradual smooth boundary. (8 to 12 inches thick)

Bk2--18 to 35 inches; pale brown (10YR 6/3) sandy clay loam, dark brown (10YR 3/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine irregular pores; violently effervescent-lime segregated in many fine filaments and threads and in many irregularly shaped soft masses; 10 percent gravel; moderately alkaline (pH 8.4); clear irregular boundary. (15 to 20 inches thick)

2C1--35 to 46 inches; light yellowish brown (10YR 6/4) very gravelly loamy sand, dark yellowish brown (10YR 3/4) moist; single grained; loose, nonsticky and nonplastic; few very fine roots; common fine irregular pores; slightly effervescent-disseminated lime; 45 percent gravel; moderately alkaline (pH 8.2); gradual wavy boundary. (9 to 13 inches thick)

2C2--46 to 60 inches; very pale brown (10YR 7/3) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; massive; very hard, extremely firm, slightly sticky and slightly plastic; few very fine roots; few fine irregular pores; slightly effervescent-disseminated lime; 40 percent gravel; moderately alkaline (pH 8.2).

TYPE LOCATION: Harney County, Oregon; about 5 miles south of Fields and 1.5 miles east of Rabbit Hole Mine in the NE1/4NW1/4 section 7, T. 39 S., R. 35 E.

RANGE IN CHARACTERISTICS: The soils are dry for more than half the time when the soil temperature is greater than 41 degrees F. The soil is above 41 degrees F., from about March 15 to about November 15. The soil is dry from 8 to 21 inches from about June 15 to about October 15. The mean annual soil temperature is 47 to 49 degrees F. Depth to the 2C horizon is 30 to 40 inches. Rock fragments in the upper part of the particle-size control section range from 5 to 25 percent and in the lower part form 40 to 70 percent. The rock fragments are dominantly gravel. Clay in the upper part of the particle-size control section ranges from 20 to 35 percent and in the lower part form 0 to 10 percent. There is more than 15 percent fine sand or coarser in the upper part of the particle-size control section.

The A horizon has hue of 10YR or 7.5YR, value of 6 or 7 dry and 3 or 4 moist, and chroma of 2 or 3 moist and dry. It has 1 to 2 percent organic matter.

The Bk horizon has hue of 10YR or 7.5YR, value of 6 dry and 3 or 4 moist, and chroma of 3 or 4 dry and 2 or 3 moist. It is clay loam, sandy clay loam, or gravelly sandy clay loam. It is slightly to strongly effervescent.

The 2C horizon has value of 6 or 7 dry and 3 or 4 moist, and chroma of 3 or 4 dry and moist. It is very or extremely gravelly loamy sand above 40 inches; it is very gravelly loamy sand, extremely gravelly loamy sand, or very gravelly sandy loam below 40 inches. It is massive or single grained below 40 inches.

COMPETING SERIES: This is the Oreanna series. Oreanna soils are non-calcareous in the particle-size control section and the depth to the 2C horizon is 20 to 30 inches.

GEOGRAPHIC SETTING: Dixon soils are on dissected alluvial fans at elevations of 4,000 to 4,600 feet. Slopes are 0 to 15 percent. The soils formed in old alluvium. The climate is characterized by cold dry winters and warm dry summers. The mean annual precipitation is 6 to 12 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 Defenbaugh, McConnel, and Outerkirk soils. Defenbaugh soils have a fine-loamy particle-size control section. McConnel soils have a sandy-skeletal particle-size control section. Outerkirk soils have a coarse-loamy particle-size control section.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability in the upper part and rapid in the lower part.

USE AND VEGETATION: The soils are used for rangeland. Vegetation commonly is big sagebrush, black greasewood, spiny hopsage, Indian ricegrass, basin wildrye, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Southeastern Oregon; MLRA 24. The series is inextensive.

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:

Ochric epipedon

Cambic horizon - from 2 to 18 inches (Bw and Bk1 horizons; although carbonates are present at 8 to 18 inches, there is a higher concentration of carbonates at 18 to 35 inches.


National Cooperative Soil Survey
U.S.A.