LOCATION ALUKWATWATAM WA
Established Series
Rev. PNP/KDPL/SBC
09/2019
ALUKWATWATAM SERIES
Landscape--hills
Landform--benches, ridges, hillslopes on or adjacent to cinder cones and vents
Slope--0 to 60 percent
Parent material--volcanic ash, cinders, pumice
Mean annual precipitation--about 840 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy over pumiceous or cindery, glassy, frigid Humic Vitrixerands
TYPICAL PEDON: Alukwatwatam ashy sandy loam in an area of forestland, on a 28-percent, east-facing slope at an elevation of 1225 m (All textures are apparent field textures.)
Oi--0 to 5 cm; slightly decomposed needles, leaves, and twigs
A1--5 to 15 cm; ashy sandy loam, very dark grayish brown (10YR 3/2) dry, very dark gray (10YR 3/1) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; many fine and medium and few coarse roots; common very fine irregular pores; 5 percent gravel; moderately acid (pH 6.0), NaF pH 11.2; clear wavy boundary
A2--15 to 41 cm; ashy sandy loam, dark brown (7.5YR 3/4) dry, dark brown (7.5YR 3/2) moist; weak and moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; weakly smeary; many fine and medium and few coarse roots; common very fine and fine irregular pores; 5 percent gravel; moderately acid (pH 6.0), NaF pH 11.2; clear wavy boundary
Bw1--41 to 58 cm; ashy silt loam, dark brown (7.5YR 3/3) dry, dark reddish brown (5YR 3/3) moist; weak and moderate medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; common fine, medium, and coarse roots; common fine and few medium irregular pores; 10 percent gravel; slightly acid (pH 6.2), NaF pH 10.0; clear wavy boundary
2Bw2--58 to 86 cm; gravelly ashy silt loam, brown (7.5YR 4/4) dry, dark reddish brown (5YR 3/3) moist; weak and moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine, medium, and coarse roots; common fine and few medium irregular pores; 15 percent gravel-sized cinders; slightly acid (pH 6.4), NaF pH 10.0; clear wavy boundary
2Bw3--86 to 124 cm; very gravelly ashy sandy loam, dark brown (7.5YR 3/4) dry, dark reddish brown (5YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; common fine and medium irregular pores; 40 percent gravel-sized cinders; slightly acid (pH 6.4), NaF pH 10.0; clear wavy boundary
2BC--124 to 163 cm; extremely gravelly ashy coarse sandy loam, dark reddish brown (5YR 3/4) dry, dark reddish brown (5YR 3/3) moist; weak and moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine and medium roots; common fine irregular pores; 65 percent gravel-sized cinders; slightly acid (pH 6.5), NaF pH 9.8; gradual irregular boundary
2Cr--163 to 193 cm; weathered cinders and saprolitic basalt
TYPE LOCATION: Yakama Nation, Yakima County, Washington, about 800 m east of Tadpole Lake; about 525 m south and 590 m east of the northwest corner of section 27, T. 7 N., R. 16 E.; latitude 46.0657453, longitude -120.7940397, datum WGS 84 (coordinates estimated from section, township, and range)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature at a depth of 50 cm--7 to 8 degrees C
Moisture control section--usually moist, but dry in all parts 45 to 60 consecutive days following summer solstice
Depth to bedrock--more than 150 cm
Thickness of umbric epipedon--25 to 53 cm
Less than 2-mm fraction of particle-size control section
*Moist bulk density--0.65 to 0.90 g/cm3
*Content of glass--30 to 60 percent
*Acid oxalate Al plus 1/2 Fe--2 to 3 percent
*15-bar water retention--5 to 12 percent (air-dried samples)
*Content of gravel-sized cinders--0 to 30 percent in upper part, 40 to 80 percent in lower part
A horizon
Hue--5YR to 10YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--1 to 3 dry or moist
Texture--ashy sandy loam, ashy loamy sand, gravelly ashy loamy fine sand, gravelly ashy loamy sand, gravelly ashy coarse sandy loam, gravelly ashy sandy loam
Content of gravel-sized cinders and gravel--0 to 30 percent
Combined thickness--25 to 53 cm
Bw horizon
Hue--2.5YR to 7.5YR
Value--3 to 5 dry, 3 or 4 moist
Chroma--3 to 6 dry or moist
Texture--ashy sandy loam, ashy fine sandy loam, ashy silt loam, ashy loamy sand
Content of gravel-sized cinders--0 to 15 percent
Thickness--18 to 61 cm
2Bw horizon
Hue--2.5YR to 10YR
Value--3 to 6 dry, 2 or 3 moist
Chroma--2 to 4 dry or moist
Texture--gravelly silt loam, very gravelly sandy loam, extremely gravelly sandy loam, very gravelly loamy sand, very gravelly sand
Content of gravel-sized cinders--15 to 80 percent
Combined thickness--13 to 102 cm
2BC horizon
Hue--2.5YR, 5YR
Value--3 to 5 dry, 3 or 4 moist
Chroma--3 to 6 dry or moist
Texture--extremely gravelly coarse sandy loam, extremely gravelly loamy sand, extremely gravelly sand, very gravelly loamy sand, very gravelly sand
Content of gravel-sized cinders--50 to 80 percent
Thickness--5 to 38 cm
COMPETING SERIES:
Bluesters--mollic epipedon; no cambic horizon
GEOGRAPHIC SETTING:
Elevation--850 to 1225 m
Climate--cool, dry summers; cool, moist winters
Mean annual precipitation--810 to 970 mm
Mean annual air temperature--5 to 8 degrees C
Frost-free season--70 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Singh--on mountain side slopes; argillic horizon; ashy over loamy-skeletal particle-size class
Adamslake--on benches and side slopes; argillic horizon; medial over loamy particle-size class
Pird--on ridges and side slopes; cryic soil temperature regime; ashy-skeletal particle-size class
Yamash--on ridges and side slopes; argillic horizon; 50 to 100 cm (moderately deep) to a paralithic contact (basalt)
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--high
USE AND VEGETATION:
Use--timber production, livestock grazing, wildlife habitat
Vegetation--grand fir, Douglas-fir, ponderosa pine, elk sedge, sidebells pyrola, lamb's tongue fawn lily, rose, common prince's pine
DISTRIBUTION AND EXTENT: Eastern slopes of Cascade Mountains, Yakama Nation, Yakima County, 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 in this pedon
*Umbric epipedon--zone from 5 to 41 cm
*Cambic horizon--zone from 41 to 124 cm
*Andic soil properties--zone from 5 to 163 cm
*Particle-size control section--zone from 5 to 107 cm; ashy in zone from 5 to 58 cm; cindery in zone from 58 to 107 cm
Values for andic soil properties, including glass content, acid oxalate aluminum and iron, and 15-bar water retention, were estimated based on laboratory data for similar soils.
The Alukwatwatam series originally was named the Poletad series. Alukw'at watam translates to frog lake in the Yakama language. The type location for the series is about 800 m east of Tadpole Lake, on the Yakama Reservation.
5/2016--This official series description was updated according to SSR1 Technical Note 11--Content and Format of Official Series Descriptions (revised 12/2015). Most of the changes were in formatting; no major technical changes were made.
ADDITIONAL DATA:
Partial laboratory data--sample number 38D-27-1; Yakima Nation Soil Laboratory; Toppenish, Washington
National Cooperative Soil Survey
U.S.A.