LOCATION NESPELEM WAEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Haplic Haploxerollic Durixerolls
TYPICAL PEDON: Nespelem silt loam (colors are for dry soil unless otherwise stated).
A1--0 to 7 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak very fine subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine roots; common fine irregular pores; neutral (pH 7.0); clear smooth boundary.
A2--7 to 12 inches; grayish brown (10YR 5/2) silt loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; common fine irregular pores; neutral (pH 7.0); clear smooth boundary. (Combined thickness of the A horizon is 10 to 20 inches thick)
Bw--12 to 22 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common fine roots; few fine tubular pores; neutral (pH 7.2); abrupt smooth boundary. (8 to 22 inches thick)
2Bkqm--22 to 24 inches; light brownish gray (10YR 6/2) weakly lime- and silica-cemented duripan, grayish brown (10YR 5/2) moist; massive; very hard, very firm, slightly sticky and slightly plastic; few fine roots at top of duripan; few filaments and soft masses of secondary lime; slightly effervescent; strongly alkaline (pH 8.5), clear smooth boundary. (1 to 7 inches thick)
2Bk1--24 to 32 inches; light gray (2.5Y 7/2) silt loam, light brownish gray (2.5Y 6/2) moist; massive with fine varves; slightly hard, friable, slightly sticky and slightly plastic; few filaments and soft masses of secondary lime; slightly effervescent; strongly alkaline (pH 8.5); clear smooth boundary.
2Bk2--32 to 43 inches; light gray (2.5Y 7/2) silt loam, light brownish gray (2.5Y 6/2) moist; massive with fine varves; hard, firm, slightly sticky and slightly plastic; few filaments and soft masses of secondary lime; strongly effervescent; strongly alkaline (pH 8.5); clear smooth boundary.
2Bk3--43 to 60 inches; light gray (2.5Y 7/2) silt loam, light brownish gray (2.5Y 6/2) moist; massive with fine varves; hard, firm, moderately sticky and slightly plastic; few filaments and soft masses of secondary lime; slightly effervescent; strongly alkaline (pH 8.5).
TYPE LOCATION: Okanogan County, Washington; about 9 miles west of the town of Nespelem; 1,850 feet south and 1,600 feet east of the northwest corner of sec. 22, T, 29 N., R. 31 E., W. M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 48 to 52 degrees F. These soils are usually moist, but are dry in all parts between a depth of 8 and 24 inches for 90 to 105 consecutive days following the summer solstice. Depth to a weakly cemented duripan ranges from 20 to 40 inches. Depth to soft powdery lime accumulations ranges from 16 to 36 inches. The particle-size control section is 10 to 18 percent clay and less than 15 percent coarser than very fine sand or coarser by weighted average.
The A horizon has value of 4 or 5 dry, 2 or 3 moist; and chroma of 2 or 3 dry or moist. Reaction is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5YR dry or moist; value of 5 through 7 dry, 3 through 5 moist; and chroma of 2 through 4 dry or moist. It is silt loam or very fine sandy loam. Reaction is neutral to slightly alkaline.
The 2Bkqm horizon has hue of 10YR or 2.5YR dry or moist; value of 6 or 7 dry, 3 through 5 moist; and chroma of 2 through 4 dry or moist. It crushes to silt loam or very fine sandy loam. Reaction is slightly alkaline or strongly alkaline.
The 2Bk horizon has hue of 10YR, 2.5Y, or 5Y, value of 6 or 7 dry, 4 through 6 moist; and chroma of 1 through 4 dry or moist. It is stratified (varved) silt loam, very fine sandy loam, and silty clay loam. It is slightly alkaline or strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Nespelem soils are on terraces and terrace escarpments which are commonly dissected. These soils formed in a mantle of loess overlying calcareous glaciolacustrine sediments. Slopes are 0 to 65 percent. Elevations range from 1,200 to 3,000 feet. The climate is characterized by warm, dry summers and cold, moist winters. Average annual precipitation ranges from 11 to 15 inches. The mean January temperature is about 25 degrees F; mean July temperature is about 70 degrees F; and the mean annual air temperature is 47 to 49 degrees F. The frost-free season is 110 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Conconully, Disautel, Emdent, Ewall, Haley, and Owhi series. All these soils lack a duripan. In addition, Conconully, Disautel, and Owhi soils are coarse-loamy. Emdent soils are somewhat poorly drained and have a sodium adsorption ratio greater than 13 in the upper 20 inches. Ewall soils are sandy. Haley soils are coarse-loamy over sandy or sandy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained, slow to very rapid runoff; moderate permeability above the duripan.
USE AND VEGETATION: Principal uses are hay and pasture, dryland, small grains, domestic livestock grazing, and wildlife habitat. The native vegetation is bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, threetip sagebrush, rabbitbrush, and arrowleaf balsamroot. Some areas have widely scattered ponderosa pine.
DISTRIBUTION AND EXTENT: North-central Washington. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan County, Washington, 1972.
REMARKS: Diagnostic horizon and features recognized in this pedon are a mollic epipedon from the surface to 12 inches, a cambic horizon from 12 to 22 inches, and a weakly cemented duripan at 22 to 24 inches. Xeric soil moisture regime.