LOCATION ELLUM OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Xereptic Haplodurids
TYPICAL PEDON: Ellum fine sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; light brownish gray (10YR 6/2) fine sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; mildly alkaline (pH 7.6); clear smooth boundary. (3 to 5 inches thick)
C1--5 to 13 inches; light brownish gray (10YR 6/2) fine sandy loam, dark brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; mildly alkaline (pH 7.6); clear wavy boundary. (4 to 10 inches thick)
IIC2--13 to 23 inches; pale brown (10YR 6/3) very gravelly fine sandy loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 60 percent pebbles; mildly alkaline (pH 7.6); clear wavy boundary. (3 to 13 inches thick)
IIC3ca--23 to 28 inches; light brownish gray (10YR 6/2) very gravelly fine sandy loam, dark brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 60 percent pebbles and 5 percent cobbles; moderately calcareous; pebbles and cobbles coated with lime; moderately alkaline (pH 8.0); abrupt wavy boundary. (3 to 15 inches thick)
III4sicam--28 to 36 inches; very gravelly duripan; massive; strongly cemented, very firm, very hard; silica and lime coatings on underside of pebbles; root mat on surface of pan.
TYPE LOCATION: Morrow County, Oregon; 30 feet east of road in the SW1/4 SW1/4 NW1/4 section 27, T. 3 N., R. 26 E.
RANGE IN CHARACTERISTICS: The soils are usually dry and are dry each year for more than 90 consecutive days following the summer solstice between depths of 8 to 24 inches and are moist in some part within depths of 8 to 24 inches for a continuous period equal to more than 1/4 of the time the soil temperature at depth of 20 inches exceeds 41 degrees F. The mean annual soil temperature ranges from 51 to 56 degrees F. The solum is mildly to moderately alkaline throughout and calcareous in the lower portion. Depth to lime is 10 to 24 inches. Depth to the duripan ranges from 20 to 40 inches. Depth to bedrock is greater than 60 inches.
The A horizon has value of 3 or 4 moist and chroma of 2 or 3 dry. It is fine sandy loam or sandy loam.
The C horizon has value of 3 or 4 moist and chroma of 2 or 3 dry and moist. It ranges from fine sandy loam to gravelly fine sandy loam in the C1 horizon and very gravelly fine sandy loam or very gravelly sandy loam in the IIC2 and IIC3ca horizons. Rock fragments in the C2 and C3 horizons range from 2 to 10 percent cobbles and 40 to 65 percent pebbles.
The duripan ranges from weakly to strongly cemented.
COMPETING SERIES: These are the Gravden and Jacquith series. Gravden soils are medium textured above the duripan and are 10 to 20 inches deep to the duripan. Jacquith soils are sandy and have less than 35 percent rock fragments in their control section.
GEOGRAPHIC SETTING: Ellum soils are on terraces, have slopes of 2 to 12 percent, and are at elevations of 300 to 800 feet. The soils formed in mixed moderately coarse textured alluvium. The climate is semiarid with an average annual precipitation of 7 to 9 inches, hot dry summers and cool moist winters. Mean annual temperature is 49 to 54 degrees F., mean winter temperature is 34 to 36 degrees F., and mean summer temperature is 71 to 73 degrees F. The frost-free season ranges from 140 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Burbank, Irrigon, Royal, Sagehill and Taunton soils. Burbank soils are sandy-skeletal. Irrigon soils are 20 to 40 inches deep to a paralithic contact. Royal soils lack a duripan. Sagehill soils are coarse-loamy and 20 to 40 inches deep to lacustrine material. Taunton soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability to the pan and very slow in the pan.
USE AND VEGETATION: Principal uses are for rangeland and for wildlife. Vegetation is mainly bluebunch wheatgrass, needleandthread, Sandberg bluegrass, gray rabbitbrush and big sagebrush.
DISTRIBUTION AND EXTENT: North-central Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Morrow County, Oregon, 1976.
NSTH 17, RECLASSIFICATION ONLY, 3/95