LOCATION WASKU WA
Established Series
Rev. PNP/KDPL/SBC
09/2019
WASKU SERIES
Landscape--mountains, plateaus
Landform--mountain slopes, ridgetops
Slope--0 to 60 percent
Parent material--volcanic ash mixed with colluvium and residuum derived from basalt
Mean annual precipitation--about 1650 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy-skeletal over loamy-skeletal, amorphic over isotic Alfic Vitricryands
TYPICAL PEDON: Wasku gravelly ashy sandy loam in an area of forestland, on a 20-percent, northwest-facing side slope at an elevation of 1550 m (All textures are apparent field textures.)
Oi--0 to 3 cm; slightly decomposed forest litter mixed with 1980 Mount St. Helens volcanic ash 6 mm thick
A--3 to 28 cm; gravelly ashy sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and coarse roots; few fine irregular pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5), NaF pH 11.5; gradual wavy boundary
Bw--28 to 58 cm; very gravelly ashy sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and coarse roots; few fine irregular pores; 35 percent gravel and 15 percent cobbles; moderately acid (pH 6.0), NaF pH 10.5; clear wavy boundary
2Bt--58 to 163 cm; very gravelly loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and plastic; common fine and medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 40 percent gravel and 10 percent cobbles; slightly acid (pH 6.5), NaF pH 9.5
TYPE LOCATION: Yakama Nation, Yakima County, Washington; about 610 m west and 180 m south of the northeast corner of section 25, T. 11 N., R. 13 E.; latitude 46.4152448, longitude -121.1330289, datum WGS 84 (coordinates estimated from section, township, and range)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature at a depth of 50 cm--4 to 7 degrees C
Mean summer soil temperature--6 to 8 degrees C
Upper part of particle size-control section--6 to 8 percent clay; 35 to 50 percent basalt fragments by weighted average, generally increasing in abundance as depth increases
Lower part of particle-size control section--argillic horizon; 20 to 27 percent clay; 35 to 70 percent basalt fragments
Volcanic ash mantle
*Thickness--40 to 75 cm
*Moist bulk density--0.75 to 0.9 g/cm3
*Volcanic glass content--5 to 30 percent
*Acid oxalate aluminum plus 1/2 iron--2 to 3 percent
*15-bar water retention--12 to 15 percent (air-dried samples)
A horizon
Hue--10YR, 7.5YR
Value--5 or 6 dry
Chroma--3 or 4 dry or moist
Rock fragment content--15 to 25 percent
Thickness--15 to 36 cm
Bw horizon
Hue--10YR, 7.5YR
Value--5 or 6 dry, 3 or 4 moist
Chroma--4 dry or moist
Texture--very gravelly ashy sandy loam, very gravelly ashy loam, very cobbly ashy loam
Rock fragment content--35 to 60 percent
Reaction--5.6 to 6.5
Thickness--25 to 38 cm
2Bt horizon
Hue--10YR, 7.5YR
Value--5 or 6 dry, 3 or 4 moist
Chroma--3 or 4 dry or moist
Texture--very gravelly loam, very cobbly loam, extremely cobbly loam
Rock fragment content--35 to 70 percent
Reaction--5.6 to 6.5
COMPETING SERIES:
Hasshollow--the upper part of the control section is finer than ashy sandy loam
Vester--the upper part of the control section is finer than ashy sandy loam
GEOGRAPHIC SETTING:
Elevation--1200 to 1850 m
Climate--cool, wet winters; relatively warm, dry summers
Mean annual precipitation--1300 to 2000 mm
Mean annual air temperature--3 to 7 degrees C
Frost-free season--35 to 75 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Foggyflat--on mountain benches, plateaus, and side slopes; ashy particle-size class
Milling--on mountain side slopes and ridgetops; loamy-skeletal particle-size class
Pird--on mountains; ashy-skeletal particle-size class
Satus--on mountain side slopes; loamy-skeletal particle-size class
Wakshum--on mountain ridgetops, plateaus, and side slopes; ashy over loamy-skeletal particle-size class
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--high
USE AND VEGETATION:
Use--dominantly timber production, wildlife habitat, and watershed
Native vegetation--subalpine fir, mountain hemlock, Pacific silver fir, Engelmann spruce, elk sedge, Cascade azalea, big huckleberry, queencup beadlily, beargrass, smooth woodrush
DISTRIBUTION AND EXTENT: East slopes of Cascade Mountains, in south-central Washington; MLRA 6; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Yakama Nation, Yakima County, Washington; 2014
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Cambic horizon--zone from 28 to 58 cm
*Argillic horizon--zone from 58 to 163 cm
*Particle-size control section--3 to 103 cm
*Andic soil properties--zone from 3 to 58 cm
Wasku is the Yakama word for grass. The type location for this series is southwest of an area referred to as Brush Corral. The grass in this area is grazed by wild and domestic animals. This series originally was named the Ritaclair series.
National Cooperative Soil Survey
U.S.A.