LOCATION IRRIGON OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Haplocambids
TYPICAL PEDON: Irrigon fine sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; neutral (pH 6.6); abrupt smooth boundary. (2 to 4 inches thick)
Bw1--3 to 18 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; neutral (pH 6.6); clear wavy boundary. 910 to 20 inches thick)
Bw2--18 to 23 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; neutral (pH 6.6); abrupt wavy boundary. (5 to 18 inches thick)
2Cr--23 inches; semiconsolidated tuffaceous sandstone; massive; very hard; common black stains on fracture surfaces.
TYPE LOCATION: Morrow County, Oregon; in the NE1/4 SW1/4 NW1/4 section 15, T.3N., R.26E.
RANGE IN CHARACTERISTICS: The soils are dry in all parts more than half the time (cumulative) that the soil temperature is above 41 degrees F., but are moist during the winter and are moist in some part between depths of 8 to 24 inches for more than 1/4 of the time (cumulative) that the soil temperature is 41 degrees F. or higher at a depth of 20 inches. The mean annual soil temperature ranges from 54 to 56 degrees F. Depth to a paralithic contact or semiconsolidated tuffaceous sandstone is 20 to 40 inches. The ochric epipedon has less than one percent organic matter in the upper 7 inches when mixed.
The A horizon has value of 5 or 6 dry and chroma of 2 or 3 dry and moist. It is fine sandy loam or sandy loam.
The B2 horizon has value of 5 or 6 dry and 3 or 4 moist. It is fine sandy loam or loam and has less than 18 percent clay, 0 to 5 percent pebbles, and 0 to 5 percent cobbles. Few to common black stains are on fracture surfaces of the semiconsolidated sandstone. Fractures are 4 to 6 inches apart.
COMPETING SERIES: These are the Adkins, Chedahap, Clems, Crestline, Deschutes, Haybourne, Kecko, Prosser, Rebel, Royal, Sagehill, Scooteney, Vining and Wiehl series. Adkins, Chedahap, Clems, Crestline, Haybourne, Kecko, Rebel, Royal, Sagehill and Scooteney soils are deeper than 40 inches to bedrock or semiconsolidated sediments. Also, Adkins, Chedahap, Crestline, Kecko, Rebel, Royal, Sagehill and Scooteney soils are calcareous above depth of 43 inches. Deschutes soils have 20 to 60 percent pumice and are 20 to 40 inches deep tl a lithic contact. Prosser soils have a lithic contact at depths of 20 to 40 inches, have textures of very fine sandy loam and silt loam and are calcareous in some part. Vinging soils are very stony and are 20 to 40 inches deep to a lithic contact. Wiehl soils have secondary lime above semiconsolidated silty lacustrine sediments.
GEOGRAPHIC SETTING: Irrigon soils are on high terraces at elevations of 400 to 700 feet. Slopes are 2 to 12 percent. The soils formed in moderately coarse and medium textured alluvium weathered from basaltic and quartzitic materials. The climate is semiarid with an average annual precipitation of 7 to 8 inches; hot dry summers, cool moist winters with mean annual temperature of to 54 degrees F.; mean winter temperature is 34 degrees to 36 degrees F.; and the mean summer temperature is 71 to 73 degrees F. The frost free season ranges from 160 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ellum and Taunton soils and the competing Royal and Sagehill soils. Ellum and Taunton soils are 20 to 40 inches deep to calcareous duripans.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Principal use is for rangeland. Other uses are wildlife habitat and irrigated pasture. Vegetation is bluebunch wheatgrass, Sandberg bluegrass, forbs and shrubs.
DISTRIBUTION AND EXTENT: North central Oregon. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Morrow County, Oregon, 1977.
NSTH 17, RECLASSIFICATION ONLY, 3/95