LOCATION DART WAEstablished Series
TAXONOMIC CLASS: Mixed, mesic Typic Xeropsamments
TYPICAL PEDON: Dart loamy coarse sand - grazed woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; dark grayish brown (10YR 4/2) loamy coarse sand, very dark brown (10YR 2/2) moist; weak thick platy structure; soft, very friable, nonsticky and nonplastic; common fine roots; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 8 inches thick)
Bw--6 to 14 inches; brown (10YR 5/3) loamy coarse sand, dark brown (10YR 3/3) moist; weak very thick platy structure; dense, brittle; slightly hard, very friable, nonsticky and nonplastic; common fine roots; bridging of sand grains with clay and fine silt; slightly acid (pH 6.4); clear wavy boundary. (4 to 8 inches thick)
C1--14 to 19 inches; pale brown (10YR 6/3) loamy coarse sand, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; few roots; neutral (pH 6.6); clear wavy boundary. (5 to 7 inches thick)
C2--19 to 60 inches; multicolored sand; single grain; few roots; 2 percent fine pebbles; neutral (pH 6.8).
TYPE LOCATION: Ferry County, Washington; 1,452 feet south of northwest corner of section 9, T. 35 N., R. 37 E., W.M.
RANGE IN CHARACTERISTICS: Mean annual soil temperature at a depth of 20 inches ranges from 47 to 49 degrees F. Dart soils are usually moist but are dry in all parts between depths of 12 and 35 inches for 75 to 90 consecutive days following the summer solstice. The particle-size control section averages 15 to 50 percent coarse sand and very coarse sand and is 0 to 15 percent pebbles. Reaction is slightly acid or neutral.
The A horizon has value of 4 through 6 dry, 2 or 3 moist and chroma of or 3 dry or moist. It ranges from loamy coarse sand to coarse sandy loam and is 0 to 10 percent pebbles. It has less than 1 percent organic matter.
The Bw horizon has value of 4, 5 or 6 dry and 3 or 4 moist. It is loamy sand, loamy coarse sand, or sand, and is 0 to 15 percent pebbles. It is massive or has weak platy structure.
The C horizon is multicolored or has hue of 10YR or 2.5Y, value of 6 or 7 dry, 3 through 5 moist, and chroma of 2 through 4 dry or moist. It is loamy coarse sand, coarse sand, or sand and is 0 to 20 percent pebbles. Faint iron staining is in the lower part in some pedons.
COMPETING SERIES: These are the Bisbee, Ewall, Preston, and Santaquin series. Bisbee soils are 0 to 15 percent coarse sand and very coarse sand in the particle-size control section. Ewall soils are dry more than 90 days. Preston and Santaquin soils are mildly alkaline or moderately alkaline.
GEOGRAPHIC SETTING: Dart soils are on terraces and terrace escarpments at elevations of 1,400 to 2,800 feet. Slopes range from 0 to 65 percent. Dart soils formed in glacial outwash or alluvium from acid igneous rocks. The mean annual temperature is 46 degrees F., average annual precipitation is 15 to 20 inches, and the frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Phoebe, Scala, Spens and Springdale soils and the competing Bisbee soils. Phoebe and Scala soils are moderately coarse textured in the control section. Spens and Springdale soils are sandy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow or medium runoff; rapid permeability.
USE AND VEGETATION: Grazed woodland, woodland, and small grains. The native vegetation is ponderosa pine, bluebunch wheatgrass, junegrass, Sandberg bluegrass, and needlegrass.
DISTRIBUTION AND EXTENT: Northeastern Washington. Dart series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ferry County, Washington, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 6 inches and a particle-size control section from 10 to 40 inches that is sandy throughout.