LOCATION BREZNIAK OR

Established Series
Rev. EGH/TDT
12/2022

BREZNIAK SERIES

The Brezniak series consists of very shallow and shallow, well drained soils that formed in colluvium and residuum from igneous bedrock. Brezniak soils are on side slopes of deeply dissected tablelands,mountain flanks and mountain footslopes. Slopes are 2 to 65 percent. The mean annual precipitation is about 10 inches, and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Clayey, smectitic, mesic Aridic Lithic Argixerolls

TYPICAL PEDON: Brezniak cobbly loam on a 30 percent slope on rangeland. (Colors are for dry soil unless otherwise stated.)

A--0 to 3 inches; brown (10YR 5/3) cobbly loam, dark brown (10YR 3/3) moist; weak and moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine tubular and irregular pores; 10 percent gravel, 15 percent cobbles and 5 percent stones; neutral (pH 7.2); abrupt smooth boundary. (2 to 5 inches thick)

Bt1--3 to 7 inches; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; many very fine and fine tubular and irregular pores; common faint clay films on faces of peds; neutral (pH 7.2); clear smooth boundary. (3 to 6 inches thick)

Bt2--7 to 10 inches; reddish yellow (7.5YR 6/6) clay, strong brown (7.5YR 4/6) moist; moderate medium angular blocky structure; extremely hard, firm, moderately sticky and moderately plastic; few very fine roots; many very fine and fine tubular and irregular pores; common distinct clay films on faces of peds; 10 percent stones; neutral (pH 6.8); abrupt wavy boundary. (2 to 5 inches thick)

R--10 inches; fractured hard igneous bedrock.

TYPE LOCATION: Harney County, Oregon; 1,200 feet south and 1,200 feet west of the northeast corner of section 27, T. 35 1/2 S., R. 32 1/2 E., on the Skull Creek Butte quadrangle; (Latitude 42 degrees 28 minutes 36 seconds N., Longitude 118 degrees 49 minutes 06 seconds W., NAD 1927.

RANGE IN CHARACTERISTICS: These soils are usually moist in the winter and spring, and dry from July through October. The mean annual soil temperature is 47 to 50 degrees F. The mean summer soil temperature is 63 to 65 degrees F. The depth to bedrock is 7 to 12 inches. The mollic epipedon is 7 to 10 inches thick, contains 1 to 2 percent organic matter and includes all or part of the argillic horizon. The particle-size control section averages 35 to 45 percent clay and 5 to 15 percent rock fragments.

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 loam with 18 to 27 percent clay. The lower boundary is abrupt or clear and there is a 15 to 23 percent (absolute) clay increase between the A and Bt horizon.

The Bt horizon has a value of 4 through 6 dry, and 2 through 4 moist, and chroma of 3 through 6 dry and moist. It is clay loam or clay with 35 to 50 percent clay.

COMPETING SERIES: These are the Bidrim, Cullius, Devada, Deven, Devnot, Dunnlake and Wylo series. Bidrim soils have 3 to 8 percent organic matter in the A horizon, are 10 to 14 inches deep to bedrock and contain 55 to 65 percent clay in the argillic horizon. Cullius soils have 10 to 30 percent glass in the A horizon. Devada soils are 12 to 20 inches deep to bedrock. Deven soils are 10 to 20 inches deep to bedrock and have a xeric moisture regime. Devnot soils have a xeric moisture regime. Dunnlake soils are 12 to 20 inches to bedrock. Wylo soils have a mean annual soil temperature of 54 to 59 degrees F.

GEOGRAPHIC SETTING: Brezniak soils occur on side slopes of deeply dissected tablelands, mountain flanks and mountain footslopes. The soils formed in colluvium and residuum from igneous rock. Slopes are 2 to 65 percent. Elevation ranges from 3,600 to 6,800 feet. The climate is semiarid with cool, moist winters and warm dry summers. The mean annual precipitation is 8 to 12 inches. The mean annual air temperature is 45 to 49 degrees F. The frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lonegrave, Longcreek, Mahoon, and Pernty soils. Lonegrave soils are 20 to 40 inches deep to bedrock and are loamy-skeletal. Longcreek soils are 10 to 20 inches deep to bedrock and are clayey-skeletal. Mahoon soils are 20 to 40 inches to bedrock. Pernty soils are loamy-skeletal and are 10 to 20 inches to bedrock.

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

USE AND VEGETATION: The soils are used for rangeland and wildlife habitat. Vegetation commonly is bluebunch wheatgrass, Thurber needlegrass, Wyoming big sagebrush, Sandberg bluegrass, stiff sagebrush, and Idaho fescue.

DISTRIBUTION AND EXTENT: Southeastern Oregon; MLRA 23 and 10. The series is of small extent.

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

SERIES ESTABLISHED: Harney County, Oregon; 1997.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - from a depth of 0 to 7 inches (A and Bt1 horizons)

Argillic horizon - from a depth of 3 to 10 inches (Bt1 and Bt2 horizons)

Particle-size control section - from a depth of 0 to 10 inches (A, Bt1, and Bt2 horizons) averages 12 percent rock fragments and 38 percent clay.

Aridic soil moisture regime bordering xeric.

National Cooperative Soil Survey
U.S.A.