LOCATION DRYBED OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Calciargidic Argixerolls
TYPICAL PEDON: Drybed silt loam - on a gently sloping terrace, rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 4 inches; very dark brown (10YR 2/2) silt loam, dark gray (10YR 4/1) dry; moderate fine platy structure; soft, friable, nonsticky and nonplastic; common very fine, fine and medium roots; common very fine, fine and medium irregular pores; 3 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary.
A2--4 to 13 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; moderate coarse platy structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine, fine and medium tubular pores; 3 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary. (Combined thickness of the A horizon is 8 to 20 inches)
Btk1--13 to 22 inches; very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (10YR 5/2) dry; moderate medium subangular blocky structure; hard, firm, slightly sticky and plastic; few very fine and fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds; slightly effervescent with segregated lime in filaments or threads; 3 percent gravel; moderately alkaline (pH 8.4); clear smooth boundary.
Btk2--22 to 29 inches; very dark grayish brown (10YR 3/2) silty clay loam, brown (10YR 5/3) dry; strong medium subangular blocky structure; very hard, very firm, sticky and plastic; few very fine and fine roots; few very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; strongly effervescent with segregated lime in seams; 3 percent gravel; strongly alkaline (pH 8.8); clear smooth boundary. (Combined thickness of the Btk horizon is 12 to 25 inches)
2Ck1--29 to 40 inches; brown (10YR 4/3) sandy clay loam, light gray (10YR 7/2) dry; massive; very hard, very firm, slightly sticky and slightly plastic; violently effervescent with segregated lime in blotches; 3 percent gravel; strongly alkaline (pH 8.8); gradual smooth boundary.
2Ck2--40 to 60 inches; dark yellowish brown (10YR 4/4) sandy clay loam, light gray (10YR 7/2) dry; massive; hard, firm, nonsticky and nonplastic; violently effervescent with disseminated lime and segregated lime in blotches; 3 percent gravel; moderately alkaline (pH 8.4).
TYPE LOCATION: Jefferson County, Oregon, about 500 feet west and 1500 feet south of the NE corner of section 18, T.9 S., R.13 E. (Latitude 44 degrees, 47 minutes, 30 seconds N, Longitude 121 degrees, 13 minutes W) Warm Springs Indian Reservation.
RANGE OF CHARACTERISTICS: These soils are usually dry and are dry in all parts of the moisture control section more than half the time (cumulative) that the soil temperature at a depth of 20 inches is above 41 degrees F. The mean annual soil temperature is 52 to 54 degrees F. Depth to bedrock is greater than 60 inches. The mollic epipedon is 10 to 20 inches thick. Depth to secondary carbonates is 8 to 20 inches. The particle-size control section averages 27 to 35 percent clay and 15 to 30 percent fine sand and coarser.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 1 or 2 moist and dry. It contains 0 to 5 percent gravel and 1 to 2 percent organic matter.
The Btk horizon has value of 2 to 4 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It is silty clay loam or clay loam and contains 0 to 5 percent gravel and less than 1 percent organic matter.
The 2Ck horizon has value of 4 or 5 moist, 6 or 7 dry and chroma of 2 to 4 moist and dry. It is sandy clay loam, loam or sandy loam and contains 0 to 5 percent gravel.
COMPETING SERIES: These are the Axford (T), Babbington, Bamos (T), Benwy (T), Bidwell, Brogan (T), Caliralls (T), Doyce, Haw, Lucero (T) and Zen series. Axford soils are 40 to 60 inches to bedrock and 20 to 30 inches to secondary carbonates. Babbington soils are dry for 90 to 120 consecutive days. Bamos soils are 20 to 40 inches to bedrock. Benwy soils have a duripan at a depth of 40 to 60 inches and secondary carbonates at a depth of 24 to 38 inches. Bidwell soils have a mean annual soil temperature of 48 to 50 degrees F. and secondary carbonates at a depth of 20 to 40 inches. Brogan soils have a mean annual soil temperature of 49 to 51 degrees F. and lacustrine sediments at a depth of 25 to 40 inches. Caliralls soils have 15 to 25 percent rock fragments in the particle-size control section and a depth of 25 to 43 inches to secondary carbonates. Doyce soils have a mean annual soil temperature of 47 to 49 degrees F., a Bk horizon with 5 to 35 percent rock fragments, and 15 to 40 percent calcium carbonate equivalent throughout. Haw soils are 22 to 38 inches to secondary carbonates. Lucero soils have a mean annual soil temperature of 50 to 52 degrees F. and 15 to 35 percent rock fragments in the particle-size control section. Zen soils are 20 to 40 inches to bedrock.
GEOGRAPHIC SETTING: Drybed soils are on nearly level to moderately sloping terraces. The soil formed in alluvium derived from mixed sources with an influence of loess in the surface. Slopes are 0 to 8 percent. Elevations are 1,200 to 3,800 feet. The climate is characterized by cool and moist winters and hot and dry summers. The mean annual precipitation is 9 to 12 inches. The mean annual temperature is 48 to 52 degrees F. The frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Antoken, Madras, Ruckles, Ruclick, Simas and Skoven soils. Antoken soils are on north-facing slopes and clayey-skeletal. Madras soils are on adjacent terraces, fine-loamy and moderately deep to welded tuff. Ruckles soils are on south- facing slopes, clayey-skeletal and shallow to volcanic tuff. Ruclick soils are on south-facing slopes, clayey-skeletal and moderately deep to basalt. Simas soils are on south- facing slopes and fine, montmorillonitic. Skoven soils are on adjacent terraces, clayey-skeletal and shallow to volcanic tuff.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. The native vegetation is basin wildrye, bluebunch wheatgrass and willow.
DISTRIBUTION AND EXTENT: North-central Oregon; MLRA 10. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County (Warm Springs Indian Reservation), Oregon, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of approximately 13 inches ( A1 and A2 horizons).
Aridic moisture regime with more than 120 dry days.
Argillic horizon - the zone from 13 to 29 inches (Btk1 and Btk2 horizons).
Mollic colors, but less than 1 percent organic matter from 13 to 29 inches (Btk1 and Btk2 horizons).
Secondary carbonates at 13 inches.