LOCATION VALBY OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Calcic Haploxerolls
TYPICAL PEDON: Valby silt loam - cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; neutral (pH 6.8); clear smooth boundary. (5 to 10 inches thick)
Bw1--8 to 14 inches; very dark grayish brown (10YR 3/2) heavy silt loam, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (5 to 10 inches thick)
Bw2--14 to 25 inches; dark brown (10YR 4/3) heavy silt loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; neutral (pH 7.2); clear wavy boundary. (4 to 12 inches thick)
Ck--25 to 30 inches; dark brown (10YR 4/3) heavy silt loam, brown (10YR 7/2) dry; massive; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; strongly calcareous mycelial lime; 5 percent gravel; moderately alkaline (pH 8.3); abrupt wavy boundary. (4 to 12 inches thick)
2R--30 inches; fractured basalt; fragments lime-coated.
TYPE LOCATION: Morrow County, Oregon; 110 feet east of Valby road in northeast 1/4 northwest 1/4 southwest 1/4, sec. 28, T. 3 S., R. 24 E.
RANGE IN CHARACTERISTICS: The soils are usually moist but are dry throughout between depths of 4 and 12 inches for 80 to 90 days following the summer solstice. They are moist in some part above a depth of 12 inches for at least half of the time that the soil temperature exceeds 41 degrees F. The mean annual soil temperature ranges from 49 to 53 degrees F. The mollic epipedon ranges from 7 to 20 inches thick. Thickness of the solum ranges from 15 to 30 inches and depth to bedrock ranges from 20 to 40 inches. The control section is silt loam with 18 to 24 percent clay, less than 15 percent coarser than very fine sand and less than 5 percent coarse fragments.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry.
The Bw horizon has value of 3 or 4 moist, 4 or 5 dry and chroma of 2 or 3 moist or dry. It has weak or moderate structure.
The C horizon has value of 4 or 5 moist, 6 or 7 dry, and chroma of 2 or 3 moist and dry. It is moderately or strongly calcareous and has segregated lime. Rock fragments range from none to 10 percent.
COMPETING SERIES: These are the Calouse, Condon, Curant, Kearns, Rhea and Staley series. Calouse, Curant, Kearns, Rhea and Staley soils are deeper than 40 inches to bedrock. Also, Calouse and Curant soils have a mollic epipedon thicker than 20 inches.
GEOGRAPHIC SETTING: Valby soils are on upland slopes at elevations of 1,600 to 3,000 feet. Slopes range from 1 to 30 percent. These soils formed in loess with an appreciable component of volcanic ash, overlying basalt. The climate is semiarid with cool moist winters and dry summers. The mean winter temperature is 31 to 35 degrees F, mean summer temperature is 62 to 66 degrees F, mean annual temperature is 47 to 51 degrees F. The mean annual precipitation ranges from 10 to 14 inches. The average frost-free period is 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bakeoven, Lickskillet and Wrentham soils and the competing Rhea soils. Bakeoven, Lickskillet and Wrentham soils contain more than 35 percent fragments coarser than 2 millimeters. Also, Bakeoven and Lickskillet soils are less than 20 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderate permeability.
USE AND VEGETATION: The soils are used for dryfarm small grains, hay, pasture and range. Native vegetation is mainly bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass and forbs such as yarrow, phlox and buckwheat.
DISTRIBUTION AND EXTENT: North-central Oregon. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Morrow County, Oregon, 1977.