LOCATION WAMBA WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Typic Endoaquolls
TYPICAL PEDON: Wamba silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 5 inches; very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; slightly hard, friable, nonsticky, slightly plastic; many fine roots; slight effervescence; moderately alkaline (pH 8.0); abrupt smooth boundary. (3 to 6 inches thick)
B21g--5 to 9 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; common medium distinct mottles, reddish brown (5YR 4/4) and strong brown (7.5YR 5/6) dry weak medium subangular blocky structure; hard, firm, nonsticky, slightly plastic; common fine roots; common fine pores; mildly alkaline (pH 7.6); clear wavy boundary. (2 to 5 inches thick)
B22g--9 to 17 inches; dark gray (10YR 4/1) silt loam, gray (10YR
6/1) dry; common medium faint mottles, dark brown (10YR 4/3) and brownish yellow (10YR 6/6) dry; weak medium subangular blocky structure; hard, friable, slightly sticky, plastic; common fine roots; common fine pores; mildly alkaline (pH 7.8); gradual wavy boundary. (5 to 12 inches thick)
2C1g--17 to 23 inches; dark gray (10YR 4/1) gravelly silt loam, gray (10YR 6/1) dry; massive; common medium faint mottles; dark brown (10YR 4/3) and brownish yellow (10YR 6/6) dry; slightly hard, friable, slightly sticky, plastic; mildly alkaline (pH 7.8); gradual wavy boundary. (5 to 15 inches thick)
3C2--23 to 31 inches; very gravelly sand of which 60 percent is over 1 inch in diameter; some of the pebbles are lime silica coated on the lower side; single grained; loose, nonsticky, nonplastic; common roots; moderately alkaline (pH 8.0).
TYPE LOCATION: Benton County, Washington; 75 feet north of Johnson Road and 1,200 feet west of the Missimer Road in the SW1/4 SE1/4 SE1/4 section 28, T.9N., R.24E., WM.
RANGE IN CHARACTERISTICS: The solum ranges from 10 to 20 inches thick. Depth to contrasting textures range from 18 to 36 inches. These soils are usually moist and are saturated at some period. The mean annual soil temperature ranges from 50 to 56 degrees F. The soil is mildly alkaline or moderately alkaline.
The A1 or Ap horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 or 2 dry or moist. It has weak or moderate granular or subangular blocky structure.
The B2g horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 1 or 2 dry or moist and is mottled. It is silt loam or gravelly silt loam.
The Cg horizon has value of 5 or 6 dry, and is mottled.
COMPETING SERIES: These are the Moulton and St. Joe series. Moulton soils are fine sandy loam or sandy loam above the contrasting textures. St. Joe soils are medium acid and are sandy loam and fine sandy loam texture in the control section above the contrasting material.
GEOGRAPHIC SETTING: Wamba soils are on nearly level to slightly concave terraces at elevations of 675 to 800 feet. They formed in gravelly alluvium. These soils occur in an arid climate with hot, dry summers and cool, moist winters. The mean annual precipitation is 6 to 8 inches. The mean January temperature is 29 degrees F.; the mean July temperature is 71 degrees F.; and the mean annual temperature is 50 degrees F. The frost free season is 135 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Prosser and Scooteney soils. These soils are well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability.
USE AND VEGETATION: Hay and pasture. Vegetation consists of cultivated grasses and legumes, inland saltgrass, Russian olive, willow and sedge.
DISTRIBUTION AND EXTENT: South central Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Benton County, Washington, 1971.
REMARKS: Wamba soils were formerly classified as Low Humic Gley soils.