LOCATION CROWCAMP OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Palexerolls
TYPICAL PEDON: Crowcamp silty clay loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; gray (10YR 5/1) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak medium platy structure; hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; many fine and very fine vesicular pores; neutral (pH 7.2); abrupt smooth boundary. (3 to 9 inches thick)
2Bt1--3 to 11 inches; grayish brown (10YR 5/2) clay, very dark brown (10YR 2/2) moist; moderate medium and fine prismatic structure parting to strong medium and fine blocky; hard, firm, very sticky and very plastic; many fine roots; common very fine tubular pores; slightly alkaline (pH 7.4); gradual smooth boundary. (6 to 12 inches thick)
2Bt2--11 to 23 inches; dark gray (10YR 4/1) clay, very dark grayish brown (10YR 3/2) moist; moderate fine and medium blocky structure; hard, firm, very sticky and very plastic; many fine roots; common very fine tubular pores; few pressure faces, few faint clay films lining pores; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 20 inches thick)
2Bt3--23 to 30 inches; dark gray (10YR 4/1) clay, very dark grayish brown (10YR 3/2) moist; weak medium and fine blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many roots; common very fine tubular pores; common pressure faces, few faint clay films lining pores; many white noncalcareous masses; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (5 to 10 inches thick)
3Bkq--30 to 44 inches; grayish brown (2.5Y 5/2) loam, very dark grayish brown (2.5Y 3/2) moist; weak platy structure; hard, very firm and brittle, slightly sticky and slightly plastic; few fine roots; many lime streaks on plates and as mycelia; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (10 to 20 inches thick)
3C1--44 to 53 inches; light brownish gray (2.5Y 6/2) loam, olive brown (2.5Y 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; moderately alkaline (pH 8.0); gradual smooth boundary. (10 to 20 inches thick)
4C2--53 to 68 inches; light brownish gray (2.5Y 6/2) very gravelly loam, olive brown (2.5Y 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; 40 percent gravel; moderately alkaline (pH 8.0).
TYPE LOCATION: Harney County, Oregon; about 3 1/2 miles west of the community of Buchanan, 150 feet south of gate in south right of way fence on U.S. Highway 20 in the NW1/4, NW1/4, NW1/4 section 32, T. 22 S., R.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 45 to 47 degrees F. Depth to bedrock is greater than 60 inches. The soils are dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. The mollic epipedon is 20 to 30 inches thick. There is a 15 to 20 percent clay increase (absolute) between the A and 2Bt horizons. Depth to the hard brittle layer is 25 to 40 inches. The soil is ponded in the spring from about March to April. There is an apparent water table at 2.5 to 5.0 feet from March to May. Linear extensibility of the upper 100 cm is 6.0 cm or more.
The A horizon has value of 4 to 6 dry, 2 to 4 moist and chroma of 1 or 2 moist and dry. The upper 7 inches when mixed has value of 5 dry and 3 moist. It is neutral or slightly alkaline. It is loam, silt loam or silty clay loam with 15 to 35 percent clay.
The 2Bt horizon has value of 4 or 5 dry, 2 or 3 moist and chroma of 1 or 2. It is slightly or moderately alkaline. It is clay or silty clay, with 40 to 55 percent clay. It has pressure faces and faint clay films.
The 3B and 3C horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 2 through 4. It is loam or gravelly loam with 0 to 20 percent gravel. The 4C horizon is gravelly or very gravelly loam with 20 to 50 percent gravel.
COMPETING SERIES: These are the Bigflat, Carryback, Hart, Lacrol, Tippett and Zumwalt series. Bigflat, Hart, and Lacrol soils are well drained and have mollic epipedons less than 20 inches thick. Carryback and Zumwalt soils are 20 to 40 inches deep to bedrock. Tippett soils are well drained and have albic material at 10 to 20 inches.
GEOGRAPHIC SETTING: The soils are on low terraces in basins at elevations of 4,000 to 4,500 feet. Slopes range from 0 to 2 percent. The soils formed in alluvium and lacustrine deposits. The climate is semiarid and summers are dry. The mean annual precipitation is 10 to 12 inches and the mean annual temperature is 43 to 45 degrees F. The frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fury, Skidoosprings and Widowspring soils. Fury and Widowspring soils are fine-silty and lack argillic horizon. Skidoosprings soils are coarse-loamy and have aquic conditions.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow permeability. Flooding is none or rare. Spring ponding, and an apparent water table below 2.5 feet in the spring.
USE AND VEGETATION: The soils are used for range and for irrigated hay and pasture. Native vegetation is mainly silver sagebrush, creeping wildrye, Nevada bluegrass and mat muhly.
DISTRIBUTION AND EXTENT: South-central 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 0 to 23 inches
- Argillic horizon - from 3 to 30 inches
- Aridic bordering on xeric soil moisture regime
- Pressure faces from 11 to 30 inches
- Abrupt A/2Bw boundary with a 15 percent absolute clay increase
ADDITIONAL DATA: Laboratory data available S88OR-025-004. Data not from the type location.