LOCATION MAYTOWN WAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Fluventic Haploxerolls
TYPICAL PEDON: Maytown silt loam - pasture. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many fine roots; strongly acid (pH 5.4); abrupt smooth boundary. (7 to 8 inches thick)
A--8 to 16 inches; dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; hard friable, slightly sticky and slightly plastic; many fine roots; moderately acid (pH 5.6); clear smooth boundary. (6 to 10 inches thick)
Bw1--16 to 28 inches; brown (10YR 4/3) heavy silt loam, brown (10YR 5/3) dry; strong fine subangular blocky structure; hard, friable, sticky and plastic; common fine roots; moderately acid (pH 5.8); gradual smooth boundary. (10 to 16 inches thick)
Bw2--28 to 36 inches; brown (10YR 4/3) silty clay loam, yellowish brown (10YR 5/4) dry; strong fine subangular blocky structure; hard, friable, sticky and plastic; few fine roots; very strongly acid (pH 5.0). (5 to 12 inches thick)
Bw3--36 to 60 inches; brown (10YR 4/3) silty clay loam, yellowish brown (10YR 5/4) dry; few fine faint light brownish gray (2.5Y 6/2) mottles, strong fine subangular blocky structure; hard, friable, sticky and plastic; few fine roots; very strongly acid (pH 5.0).
TYPE LOCATION: Thurston County, Washington; Mima Prairie area, about 4 miles southwest of Littlerock, in field 200 feet south of county road, 400 feet west of house; northwest corner section 20, T. 16 N., R. 3 W., W. M.
RANGE IN CHARACTERISTICS: The average annual soil temperature ranges from 50 to 53 degrees F. These soils are usually moist, but are dry in the moisture control section for 45 to 60 consecutive days following summer solstice in 7 years out of 10. Faint to distinct mottles are present below 30 inches. Base saturation is assumed to be below 75 percent by sum in upper 30 inches of the soil and more than 50 percent by NH40C throughout the profile.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry and chroma of 1 through 3 moist or dry. Reaction is strongly acid or moderately acid.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 through 6 moist 6 or 7 dry, and chroma of 2 to 4 moist or dry. It is silt loam or silty clay loam and has thin discontinuous layers of fine sandy loam and silty clay in some pedons. Reaction is very strongly acid to slightly acid.
COMPETING SERIES: These are the Chehalis, Nooksack, and Parehat soils in other families. Chehalis soils have a mollic epipedon more than 20 inches thick. Nooksack soils are coarse-silty.Parehat soils have grayish mottles above 30 inches.
GEOGRAPHIC SETTING: These soils are on flood plains and low terraces at elevations of 10 to 500 feet. They formed in mixed alluvium. Slopes are 0 to 3 percent. Climate is marine with 45 to 70 inches annual precipitation occurring mostly as rain during the winter; average January temperature is about 38 degrees F; average July temperature is about 63 degrees F; and the frost-free season is about 165 to 195 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Newberg and Godfrey soils and the competing Chehalis soils. Newberg soils are coarse- loamy. Godfrey soils have an aquic moisture regime and are in a fine family.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow permeability. These soils are subject to occasional brief flooding from November to March. A water table is as high as 2.5 to 3.5 feet at times from November to April.
USE AND VEGETATION: Mostly for hay and pasture and some small grains. Native vegetation is Douglas-fir, red alder, bigleaf maple, western hemlock, and western redcedar with an understory of western brackenfern, western swordfern, vine maple, trailing blackberry, Oregongrape, western rattlesnake plantain, Pacific yew, and wild ginger.
DISTRIBUTION AND EXTENT: Central-western Washington. Series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Thurston County, Washington, 1949.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 16 inches and a cambic horizon from 16 to 60 inches that is assumed to have an irregular decrease in organic carbon. Maytown soils are assumed to have less than 75 percent base saturation (by sum) in the upper 30 inches. However, there is no Fluventic Ultic subgroup of Haploxerolls provided in Soil Taxonomy.