LOCATION PRINEVILLE OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Durinodic Xeric Haplocambids
TYPICAL PEDON: Prineville ashy sandy loam, on a 1 percent slope, cropland. (Colors are for moist soils unless otherwise noted.)
Ap-- 0 to 9 inches; very dark grayish brown (10YR 3/2) ashy sandy loam, light brownish gray (10YR 6/2) dry; weak fine granular structure; soft, friable, nonsticky and nonplastic; many very fine and fine roots; many fine vesicular pores; 20 percent sand-size (0.25 to 1.0 mm) pumice, light brownish gray (10YR 6/2)dry; neutral (pH 7.0); gradual wavy boundary. (5 to 12 inches thick)
AB-- 9 to 16 inches; very dark grayish brown (10YR 3/2) ashy fine sandy loam, light brownish gray (10YR 6/2) dry; weak thick platy structure parting to weak fine subangular blocky; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common fine tubular pores; 5 percent sand-size (0.25 to 1.0 mm) pumice; slightly alkaline (pH 7.6); gradual smooth boundary. (5 to 10 inches thick)
Bw-- 16 to 20 inches; dark grayish brown (10YR 4/2) ashy fine sandy loam, light brownish gray (10YR 6/2) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; common fine tubular pores; 5 percent sand-size (0.25 to 1.0 mm) pumice; moderately alkaline (pH 8.2); clear wavy boundary. (4 to 10 inches thick)
2Bk-- 20 to 32 inches; brown (10YR 5/3) very fine sandy loam, pale brown (10YR 6/3) dry; weak thick platy structure parting to fine and medium subangular blocky; hard, firm, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; 1 inch carbonate nodules; slightly effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (5 to 15 inches thick)
2Bkq-- 32 to 47 inches; dark grayish brown (10YR 4/2) very fine sandy loam, pale brown (10YR 6/3) dry; moderate thick platy structure; very hard, very firm and brittle, nonsticky and nonplastic; few fine tubular pores; weakly cemented lenses of sand and silt; hard thin lenses of segregated lime; strongly effervescent with disseminated lime; strongly alkaline (pH 8.6); gradual irregular boundary. (6 to 15 inches thick)
3Crkq-- 47 inches; cemented fluvial and lacustrine gravel and sand, and tuffaceous sandstone and conglomerate of the Deschutes Formation.
TYPE LOCATION: Crook County, Oregon; located 1000 feet south and 1500 feet west of the NE corner of section 8, T.14 S., R.15 E.
RANGE OF CHARACTERISTICS: The soils are dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. The soils are dry in the moisture control section for 90 to 120 cumulative days following the summer solstice. The mean annual soil temperature is 50 to 54 degrees F. Depth to bedrock is 40 to 60 inches. Depth to secondary carbonates is 20 to 30 inches and depth to the hard firm brittle layer is 20 to 40 inches. The sand-size (0.25 to 1.0mm) pumice content of the upper solum ranges from 5 to 30 percent. It has a phosphate retention fo 15 to 25 percent and acid oxalate extractable aluminum plus one-half the iron is 0.4 to 0.8 percent. It has hue of 10YR or 7.5YR and is neutral or slightly alkaline in the upper part and slightly to strongly alkaline in the lower part. The particle-size control section averages 5 to 18 percent clay.
The A or Ap horizon has value of 2 or 3 moist, 4 to 6 dry, and chroma of 2 or 3 moist and dry. The sand-size (0.25 to 1.0mm) pumice content ranges from 15 to 40 percent.
The Bw horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 or 3 moist and dry. It is sandy loam, fine sandy loam, or loam. The sand-size (0.25 to 1.0mm) pumice content ranges from 5 to 15 percent.
The 2Bk and 2Bkq horizons have value of 4 or 5 moist, 5 or 6 dry, and chroma of 2 through 4, moist and dry. It is very fine sandy loam, fine sandy loam, sandy loam, or loamy sand and contain 0 to 20 percent gravel. It is slightly to violently effervescent. Calcium carbonate is 2 to 5 percent.
The 3Crkq horizon is water laid sediments or paralithic tuffaceous sandstone of the Deschutes Formation and is strongly to violently effervescent.
COMPETING SERIES: These are the Kerrfield and Patter series. These soils lack the vitri properties in the surface layer. In addition, the Patter soil is over 60 inches deep.
GEOGRAPHIC SETTING: Prineville soils are on nearly level to gently sloping terraces at elevations of 2,900 to 3,100 feet. Slopes range from 0 to 8 percent. These soils formed in mixed alluvium with an influence of volcanic ash in the surface. They are underlain by water laid sediments or paralithic tuffaceous sandstone of the Deschutes Formation. The climate is characterized by cool moist winters and hot dry summers. The mean annual precipitation is 9 to 12 inches, the mean annual temperature is 48 to 52 degrees F., and the frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ochoco, Court, and Era soils. Ochoco soils have a fine-loamy argillic horizon and are 20 to 40 inches to a duripan. Court soils are 20 to 40 inches to cemented sand and gravel. Era soils are on adjacent alluvial fans and in drainageways and are greater than 60 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained, moderately rapid permeability.
USE AND VEGETATION: Irrigated cropland; principal crops are potatoes, grain, alfalfa, and mint. Native vegetation is bluebunch wheatgrass, basin big sagebrush, and scattered western juniper.
DISTRIBUTION AND EXTENT: Central Oregon, MLRA 10, pumice zone. This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Prineville Area, Crook County, Oregon, 1963.
REMARKS: Diagnostic horizons and other features in this pedon include:
Ochric epipedon
Cambic horizon - from a depth of 16 to 32 inches (Bw and 2Bk horizons)
Durinodic subgroup - the zone from 32 to 47 inches is very hard, very firm and brittle.
Vitrixerandic feature - to a depth of 20 inches.
Deschutes Formation - semiconsolidated to cemented water-laid sediments composed of sand, gravel and silts of volcanic orgin. Interbedded ash flow tuff and tuffaceous sandstone occur in the Formation.
ADDITIONAL DATA: Characterization data for one pedon (S55-Oreg-7-18) reported in the Soil Survey of Prineville Area, Oregon, 1966.