LOCATION WINOM OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Oxyaquic Hapluderts
TYPICAL PEDON: Winom silty clay loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A--0 to 8 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; strong fine and medium subangular blocky structure; hard, friable, sticky and plastic; many fine and medium roots; many very fine irregular pores; vertical cracks 2 to 5 mm wide; slightly acid (pH 6.1); clear wavy boundary. (5 to 9 inches thick)
AC1--8 to 13 inches; black (10YR 2/1) silty clay loam, gray (10YR 5/1) dry; strong fine angular blocky structure; hard, firm, sticky and plastic; many fine and medium roots; many very fine tubular pores; vertical cracks 2 to 5 mm wide; slightly acid (pH 6.2); abrupt wavy boundary. (5 to 25 inches thick)
AC2--13 to 28 inches; black (10YR 2/1) clay, very dark grayish brown (10YR 3/2) dry; strong coarse columnar structure; very hard, very firm, very sticky and very plastic; few fine and medium roots; common very fine tubular pores; common slickensides; vertical cracks 5 to 15 mm wide; neutral (pH 7.0); clear wavy boundary. (5 to 21 inches thick)
ACk--28 to 40 inches; black (10YR 2/1) silty clay loam, grayish brown (10YR 5/2) dry; strong medium prismatic structure parting to strong medium angular blocky; very hard, very firm, sticky and plastic; few fine and medium roots; common very fine tubular pores; common slickensides; slightly effervescent, segregated lime in seams; moderately alkaline (pH 8.0); clear wavy boundary. (0 to 14 inches thick)
C--40 to 60 inches; dark yellowish brown (10YR 4/4) clay, light yellowish brown (10YR 6/4) dry; moderate medium and coarse subangular blocky structure; very hard, firm, sticky and plastic; few fine and medium roots; common very fine tubular pores; common fine to large prominent mottles; common slickensides; neutral (pH 7.2).
TYPE LOCATION: Umatilla County, Oregon; about 75 feet east of U.S. 395; SW1/4 SW1/4 section 15, T. 4 S., R. 31 E.
RANGE IN CHARACTERISTICS: The soils are usually moist but are dry between depths of 4 and 12 inches for more than 45 consecutive days following the summer solstice. The soils are also moist for more than 45 consecutive days during the winter months between depths of 4 and 12 inches. The mean annual soil temperature is 44 to 46 degrees F. These soils have at some time in most years, open cracks at a depth of 20 inches that are at least 1/2 inch wide and extend upward to the surface. Also, they have between a depth of 10 and 40 inches, slickensides close enough to intersect. The particle-size control section has 45 to 60 percent clay. Depth to basalt or weathered volcanic tuff is 60 inches or more.
The A horizon has value of 4 or 5 dry and chroma of 0 or 1 moist and dry.
The upper part of the AC horizon has value of 2 or 3 moist, 3 through 5 dry, and chroma of 0 or 1 moist and 1 or 2 dry.
The C horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 through 4 moist and dry.
COMPETING SERIES: This is the Market series. The Market soils lack segregated lime and are mottled at 30 to 60 inches.
GEOGRAPHIC SETTING: Winom soils are on stream terrace elevations of 3,300 to 4,300 feet. Slopes range from 0 to 3 percent. The soils formed in alluvium. The mean annual temperature is 43 to 48 degrees F., and the mean annual precipitation is 20 to 25 inches. The frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Albee, Anatone, Bocker, Bridgecreek, Hankins, Klicker, Silvies, and Tolo soils. Albee, Bridgecreek and Klicker soils are moderately deep to basalt or volcanic tuff. Anatone and Bocker soils are less than 20 inches deep to basalt. Hankins soils are 40 to 60 inches deep to volcanic tuff and lack open cracks in the summer. Silvies soils are poorly drained. Tolo soils are medial over loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; very slow permeability.
USE AND VEGETATION: Winom soils are used for range and hay and pasture. Native vegetation is California danthonia, rushes, sedges, and forbs.
DISTRIBUTION AND EXTENT: In valleys within the Blue Mountains of northeastern Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Umatilla County, Oregon, 1985.
NATIONAL COOPERATIVE SOIL SURVEY USA
NSTH 17, RECLASSIFICATION ONLY, 3/95