LOCATION ALSTOWN WAEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Argiduridic Argixerolls
TYPICAL PEDON: Alstown silt loam - cropland, on a northwest-facing 4 percent slope at 2,200 feet elevation. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Ap--0 to 7 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine and common medium roots; few fine irregular pores; 1 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; neutral (pH 6.6); abrupt smooth boundary.
A--7 to 13 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine and fine roots; few fine irregular pores; 5 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; neutral (pH 7.2); clear wavy boundary. (Combined thickness of the A horizon is 11 to 16 inches)
Bt1--13 to 25 inches; yellowish brown (10YR 5/4) silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine irregular and tubular pores; few faint clay films on faces of peds; 7 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; slightly alkaline (pH 7.6); clear wavy boundary.
Bt2--25 to 33 inches; light yellowish brown (10YR 6/4) silt loam; dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and fine roots; few fine irregular and tubular pores; few faint clay films on faces of peds; 3 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; slightly alkaline (pH 7.6); clear wavy boundary. (Combined thickness of Bt horizon is 18 to 22 inches.)
2Bkq1--33 to 37 inches; light yellowish brown (10YR 6/4) very gravelly silt loam, brown (10YR 4/3) moist; massive; hard, extremely firm, nonsticky and slightly plastic; few very fine and fine roots; few fine irregular pores; 7 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; 45 percent durinodes plus cicada nodules; common fine filments of secondary carbonates and disseminated secondary carbonates throughout the matix; strongly effervescent; 7 percent calcium carbonate equivalent; moderately alkaline (pH 7.8); abrupt smooth boundary. (4 to 17 inches thick).
2Bkq2--37 to 54 inches; light yellowish brown (10YR 6/4) very gravelly silt loam, brown (10YR 4/3) moist; massive; hard, very friable, nonsticky and slightly plastic; few fine tubular pores; 5 percent sand-size pumice, 0.5 to 2.0 mm. in diameter; 35 percent durinodes; many fine filaments of secondary carbonates; violently effervescent; moderately alkaline (pH 8.0); gradual irregular boundary. (0 to 17 inches thick)
3Bk--54 to 60 inches; light yellowish brown (10YR 6/4) silt loam, dark yellowish brown (10YR 4/4 moist); massive; hard, very friable, nonsticky and slightly plastic; few fine tubular pores; 5 percent sand-size pumice; common fine filaments of secondary carbonates and disseminated carbonates throughout the matrix; violently effervescent; 8 percent calcium carbonate equivalent; moderately alkaline (pH 8.0).
TYPE LOCATION: Douglas County, Washington; about 12 miles east and 4 miles south of Waterville; about 175 feet south and 100 feet west of the northeast corner of section 29, T. 24 N., R. 24 E. (Longitude 47 degrees 33' 13"N, Latitude 119 degrees 50' 00"W)
RANGE OF CHARACTERISTICS: The mean annual soil temperature is 50 to 52 degrees F. These soils are usually dry in all parts of the moisture control section more than half the time. The mollic epipedon is 10 to 18 inches thick. Clay content of the particle-size control section is 10 to 18 percent. Depth to the duric layer and secondary carbonates is 20 to 40 inches. Some pedons contain up to 10 percent sand-size pumice, 0.5 to 2.0 mm. in diameter in some horizons above the duric layer.
The A horizon has a chroma of 3 or 4 dry, 2 or 3 moist.
The Bt horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. Reaction is neutral or slightly alkaline.
The 2Bkq1 horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. Reaction is slightly to strongly alkaline. It contains 35 to 45 percent durinodes. Calcium carbonate equivalent is 5 to 10 percent.
The 2Bkq2 horizon has value of 4 or 5 moist and chroma of 3 or 4 dry or moist. It contains 35 to 45 percent durinodes. Calcium carbonate equivalent is 5 to 10 percent. Reaction is moderately or strongly alkaline.
The 3Bk horizon has values of 4 or 5 moist and chroma of 3 or 4 dry or moist. Texture is a silt loam or fine sandy loam. Calcium carbonate equivalent is 5 to 10 percent. Reaction is moderately to strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Alstown soils are formed in loess on shoulders, hill slopes and toe slopes of uplands at 1,500 to 2,800 feet elevation. Slopes are 0 to 65 percent. Climate is characterized by warm, dry summers and cool, moist winters. Average annual precipitation is 9 to 12 inches. Average January temperature is about 27 degrees F.; average July temperature is about 71 degrees F., and average annual temperature is 48 to 50 degrees F. Frost-free season is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Kester,
Renslow and
Zen soils. Kester soils are in drainageways and are moderately deep to a lithic contact. Renslow soils are on ridges. Zen soils are on broad plateaus and are moderately deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained, very slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used primarily for crop production. Wheat and barley are the principal crops. A small amount is used for livestock grazing. The native vegetation is bluebunch wheatgrass, Idaho fescue and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Washington, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 13 inches, an argillic horizon from 13 to 33 inches, and a horizon from 33 to 54 inches that has 35 to 45 percent durinodes. The particle-size control section is the zone from 13 to 33 inches (Bt1 and Bt2 horizons).
ADDITIONAL DATA: NSSL data available for this pedon, NSSL Pedon number 90P1018.