LOCATION SELAH WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Argiduridic Durixerolls
TYPICAL PEDON: Selah silt loam- abandoned field. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures).
Ap--0 to 4 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate thin platy structure; soft, very friable, slightly sticky and slightly plastic; many roots; few fine tubular pores; neutral (pH 7.0); abrupt smooth boundary. (3 to 8 inches thick)
A--4 to 7 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common roots; few fine tubular pores; neutral (pH 7.2); clear wavy boundary. (0 to 7 inches thick)
AB--7 to 13 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few roots; common fine tubular pores; slightly alkaline (pH 7.4); clear wavy boundary. (0 to 8 inches thick)
Bt1--13 to 24 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure; slightly hard, friable, slightly sticky and plastic; few roots; many fine tubular pores; few faint patchy clay films and siliceous coatings on surfaces of peds; slightly alkaline (pH 7.4); clear wavy boundary.
Bt2--24 to 29 inches; light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few roots; common fine tubular pores; few faint patchy clay films on faces of peds and lining pores; slightly alkaline (pH 7.8); abrupt smooth boundary. (Combined thickness of the Bt horizon is 10 to 20 inches)
Btk--29 to 34 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few roots; few fine tubular pores; common faint clay films on faces of peds and lining pores; free lime on ped surfaces and veins through peds; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (3 to 12 inches thick)
2Bkqm--34 to 60 inches; indurated, lime silica duripan.
TYPE LOCATION: Yakima County, Washington; 1,400 feet west and 700 feet north of the southeast corner of section 26, T.14N., R.18E.; USGS Selah topographic quadrangle; Latitude 46 degrees 40 minutes 03 seconds N. and Longitude 120 degrees 32 minutes 05 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 56 degrees F. These soils are dry between depths of 8 and 12 inches for one-half to three-fourths the time when the soil temperature is above 41 degrees F. Depth to the duripan is 20 to 40 inches. The mollic epipedon is 7 to 16 inches thick. The argillic horizon contains 18 to 35 percent clay, more than 15 percent particles coarser than very fine sand, and 0 to 30 percent rock fragments.
The A and AB horizons have value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3 dry or moist. Texture is silt loam or loam. Reaction is neutral to moderately acid.
The Bt horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 2 to 4 moist or dry. Texture is loam, silt loam, clay loam, or silty clay loam. It has faint patchy clay films on faces of peds. Reaction is neutral to moderately alkaline.
The Btk horizon has value of 5 to 7 dry, 3 to 5 moist and chroma of 2 to 4 moist or dry. Texture is clay loam, silt loam, gravelly clay loam, cobbly clay loam, or silty clay loam. Reaction is slightly alkaline to strongly alkaline. It has 0 to 30 percent rock fragments and 5 to 15 percent calcium carbonate equivalent.
The 2Bkqm horizon is indurated, has gravelly to extremely gravelly matrix, is 6 inches to 3 feet thick with 1 to 5 inch thick plates. It overlies weakly to strongly cemented alluvial material. Some pedons have a thin Bkq horizon immediately above the duripan. In some areas, basalt bedrock occurs under the old alluvium and within 60 inches of the surface.
COMPETING SERIES: These are the
Deerhorn,
Schnipper and
Seval series.
Deerhorn soils 22 to 35 inches to a lithic contact (basalt); 15 to 30 percent calcium carbonate equivalent in the Bk horizon
Schnipper soils weak to moderately cemented Bkqm horizon with 1/8 to 1/2 inch laminar indurated silica cap; durinode content of 0 to 25 percent in the Bkq horizon;
Seval soils 20 to 28 inches to duripan; MAST of 47 to 49 degrees F.; 15 to 35 percent rock fragments in the particle-size control section; 35 to 45 percent clay in the lower part of argillic horizon; receive 10 to 20 days of summer convection storms.
GEOGRAPHIC SETTING: Selah soils are on uplands, plateaus, alluvial fans, and dissected terraces. Slopes are 0 to 45 percent. These soils formed in loess and old alluvium of the Ellensburg Formation. Elevations are from 500 to 2,900 feet. They are in a semiarid climate with hot, dry summers and cool, moist winters. The mean annual precipitation is 8 to 15 inches. The mean annual temperature is 48 to 55 degrees F. The frost free season is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Harwood, Ritzville, Roza, and Willis soils. Harwood soils are on uplands and lack an argillic horizon and the duripan is silica cemented. Roza soils are on uplands and Ritzville soils are on hills and both soils lack a duripan. Willis soils are on uplands and lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability above the duripan and very slow within the duripan.
USE AND VEGETATION: These soils are used is for irrigated crop production and some livestock grazing. Native vegetation is beardless wheatgrass, bluebunch wheatgrass, Sandberg bluegrass, and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: South central Washington. MLRA 7, 8. Series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Kittitas County, Washington, 1937.
REMARKS: Diagnostics horizons and features recognized in the pedon are:
Mollic epipedon - the zone from 0 to 13 inches
Argillic horizon - the zone from 13 to 34 inches
Indurated duripan - the zone beginning at 34 inches
Particle-size control section - the zone from 13 to 33 inches (the Bt1, Bt2 and part of the Btk horizons)
The Btk horizon is not thick enough to qualify as a calcic horizon; the revised horizon depth range would include some pedons having a calcic horizon.