LOCATION WAHA WA+ID OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Waha silt loam - rangeland on a 17 percent south-facing slope 2,450 feet above sea level. (Colors are for dry soil unless otherwise noted)
A1--0 to 5 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many fine roots; slightly acid (pH 6.4); abrupt wavy boundary. (4 to 6 inches thick)
A2--5 to 13 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; common fine roots; common fine tubular pores; slightly acid (pH 6.5); clear wavy boundary. (5 to 12 inches thick)
Bt1--13 to 17 inches; brown (10YR 4/3) silty clay loam, dark brown (10YR 3/2) moist; moderate fine subangular blocky structure; very hard, firm, sticky, plastic; common fine roots; common very fine pores; thin continuous clay films on vertical surfaces; neutral (pH 6.8); clear wavy boundary. (4 to 8 inches thick)
Bt2--17 to 23 inches; brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; very hard, firm, sticky, plastic; few fine roots; few very fine pores; thin continuous very dark grayish brown clay films on all surfaces; neutral (pH 6.8); clear wavy boundary. (5 to 10 inches thick)
2Bt3--23 to 28 inches; brown (10YR 4/3) extremely gravelly clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; very hard, firm, sticky, plastic; few roots; clay films on basalt; 80 percent basalt fragments by volume; neutral (pH 6.6); abrupt irregular boundary. (0 to 10 inches thick)
2R--28 inches; basalt.
TYPE LOCATION: Columbia County, Washington; 90 feet south of road; 160 feet east and 300 feet north of the southwest corner of sec. 35, T. 9
N., R. 38 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature at depth of 20 inches ranges from 47 to 51 degrees F. These soils are usually moist but are dry in all parts between depths of 4 and 12 inches for 75 to 90 consecutive days in the summer and fall. Solum thickness and depth to bedrock range from 20 to 40 inches. The mollic epipedon ranges from 20 to 30 inches in thickness. The soils are neutral to slightly acid.
The A horizon has value of 3 to 5 dry and 2 or 3 moist, and chroma of 1 or 2. It has weak or moderate structure.
The Bt horizon has value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 or 3 moist and 2 to 4 dry. It is heavy silt loam or silty clay loam. It has weak or moderate blocky or prismatic structure.
The 2Bt horizon has value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 to 4 moist and dry. It is clay loam or silty clay loam with 20 to 85 percent basalt fragments.
COMPETING SERIES: These are the Banning, (T) Blockhouse, Coolbrith, Dotta, Drews, Gorman, Harriman, (T) Lonkey, (T) Robinette, Supan, Van Dusen, and Wapinitia. Banning, Blockhouse, Coolbrith, Dotta, Drews, Gorman, Harriman, Robinette, Van Dusen, and Wapinitia soils are more than 40 inches deep. Lonkey soils are dry about 125 consecutive days and are clay loam, loam or sandy clay loam in the upper part of the particle-size control section. Supan soils have a mean annual soil temperature more than 51 degrees F and have a mean January air temperature of about 40 degrees F.
GEOGRAPHIC SETTING: Waha soils are on foothills, plateaus, mountains, and canyon walls at elevations of 1,000 to 4,500 feet. Slopes are 0 to 65 percent. Waha soils formed in loess and residuum and colluvium from basalt. Summers are warm and dry, and winters are cold and moist. The mean January temperature is 28 to 32 degrees F. The mean July temperature is 68 to 71 degrees F. The mean annual air temperature is 45 to 50 degrees F. Average annual precipitation is 18 to 25 inches, 14 to 25 in Oregon, and the frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the DeMasters, Gwin, Jacknife, Klicker, Naff, Palouse, and Rockly series. DeMasters and Klicker soils, in associated steep northerly slopes, are frigid. Gwin soils have bedrock at depths of 10 to 20 inches. Jacknife, Naff, and Palouse soils lack bedrock at depths of less than 40 inches. Rockly soils lack an argillic horizon and are 5 to 10 inches deep to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: The lesser slopes are used for nonirrigated cropland. Winter wheat, peas, and alfalfa are common crops. Other areas are used for range. The native vegetation consists mainly of bluebunch wheatgrass, Idaho fescue, common snowberry, and widely spaced ponderosa pine.
DISTRIBUTION AND EXTENT: North-central Idaho, southeastern Washington, and northeastern Oregon. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Nez Perce-Lewis Counties, Idaho, 1917.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 23 inches, an argillic horizon from 13 to 28 inches, and a lithic contact at 28 inches.