LOCATION PATU WA
Established Series
Rev. PNP/KDPL/SBC
09/2019
PATU SERIES
Landscape--mountains, plateaus
Landform--benches, ridges, mountain slopes
Slope--0 to 60 percent
Parent material--volcanic ash over mixed ash and residuum and colluvium derived from basalt
Mean annual precipitation--about 890 mm
Mean annual air temperature--about 6 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy over loamy-skeletal, amorphic over isotic, frigid Alfic Humic Vitrixerands
TYPICAL PEDON: Patu sandy loam, stony, in an area of forestland, on a southwest-facing, 20-percent slope at an elevation of 1225 m (All textures are apparent field textures.)
Oi--0 to 5 cm; slightly decomposed needles, twigs, and cones
A--5 to 23 cm; ashy sandy loam, brown (10YR 4/3) dry, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic, weakly smeary; many very fine and fine and few medium roots; few fine irregular pores; 10 percent gravel; slightly acid (pH 6.1), NaF pH 9.8; clear smooth boundary
Bw--23 to 56 cm; ashy sandy loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/2) moist; weak fine and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; weakly smeary; many medium and coarse and common very fine and fine roots; common fine irregular pores; 10 percent gravel; slightly acid (pH 6.1), NaF pH 10.2; gradual smooth boundary
2Bt1--56 to 71 cm; very cobbly loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium and coarse roots; common very fine tubular pores; common faint clay films on faces of peds and in pores; 15 percent gravel, 20 percent cobbles, 5 percent stones, and 20 percent paragravel and paracobbles; neutral (pH 6.8); clear smooth boundary
2Bt2--71 to 84 cm; very cobbly loam, dark yellowish brown (10YR 4/4) dry, dark yellowish brown (10YR 3/4) moist; moderate medium and coarse subangular blocky structure; slightly hard, firm, moderately sticky and slightly plastic; common medium and coarse roots; few very fine tubular pores; common distinct clay films on faces of peds and in pores; 15 percent gravel, 20 percent cobbles, 5 percent stones, and 25 percent paracobbles; neutral (pH 6.8); clear smooth boundary
2Cr--84 cm; weathered basalt
TYPE LOCATION: Yakama Nation, Yakima County, Washington, about 2.5 km west of Beauty Camp, on Lincoln Plateau; about 350 m north and 60 m west from the southeast corner of section 5, T. 9 N, R. 13 E.; latitude 46.2902079, longitude -121.209358, datum WGS 84 (coordinates estimated from section, township, and range)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--7 to 8 degrees C
Soil moisture--usually moist, but dry 45 to 60 consecutive days following summer solstice
Clay content in particle-size control section--5 to 10 percent in upper part, 18 to 26 percent in lower part
Rock fragment content in particle-size control section--5 to 30 percent in upper part, 35 to 50 percent in lower part
Pararock fragment content in particle-size control section--as much as 45 percent in lower part
Thickness of volcanic ash mantle--36 to 64 cm
Depth to contrasting material--36 to 64 cm
Depth to paralithic contact--61 to 100 cm
Andic soil properties
*Moist bulk density--less than 0.9 g/cm3
*Volcanic glass content--5 to 30 percent
*Acid oxalate aluminum plus one-half iron--more than 2 percent
*15-bar water retention (air-dried samples)--less than 12 percent
Oi horizon
Thickness--3 to 8 cm
A horizon
Hue--7.5YR, 10YR
Value--3 to 5 dry, 2 or 3 moist
Chroma--1 to 4 dry, 2 or 3 moist
Texture of fine-earth fraction--ashy loamy sand, ashy sandy loam
Rock fragment content--10 to 15 percent stones and gravel
Thickness--16 to 35 cm
Bw horizon
Hue--5YR to 10YR
Value--4 or 5 dry, 2 to 4 moist
Chroma--2 to 4 moist or dry
Texture of fine-earth fraction--ashy loamy sand, ashy fine sandy loam, ashy sandy loam
Gravel content--5 to 20 percent
Cobble content--0 to 10 percent
Thickness--0 to 33 cm
Some pedons have a thick A horizon instead of a Bw horizon.
2Bt horizon
Hue--5YR to 10YR
Value--4 or 5 dry, 3 or 4 moist
Chroma--3 to 6 moist or dry
Texture of fine-earth fraction--sandy loam, loam
Gravel content--5 to 20 percent
Cobble content--10 to 30 percent
Stone content--5 to 30 percent
Combined thickness--25 to 75 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--850 to 1475 m
Mean annual air temperature--6 to 7 degrees C
Mean annual precipitation--760 to 1000 mm
Frost-free period--70 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bocker--on plateaus, structural benches, ridges, and side slopes of mountains; 10 to 25 cm (very shallow) to a lithic contact (basalt)
Icksix--on structural benches; no paralithic or lithic contact within a depth of more than 150 cm; ashy-skeletal particle-size class
Millpond--on plateaus and side slopes; 36 to 50 cm (shallow) to an indurated duripan
Singh--on side slopes of mountains; no paralithic or lithic contact within a depth of more than 150 cm
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high
USE AND VEGETATION:
Use--timber production, wildlife habitat, livestock grazing, watershed, recreation
Native vegetation--grand fir, ponderosa pine, white spirea, California hazel, pinegrass, creeping snowberry
DISTRIBUTION AND EXTENT: Eastern slopes of Cascade Mountains, Yakama Nation, Yakima County, Washington; MLRAs 3 and 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
*Umbric epipedon--zone from 5 to 56 cm
*Argillic horizon--zone from 56 to 84 cm
*Depth to paralithic contact--84 cm
*Andic properties--zone from 5 to 56 cm
*Particle-size control section--zone from 5 to 84 cm; zone from 5 to 56 cm qualifies as ashy; zone from 56 to 84 cm qualifies as loamy-skeletal
Patu is the Yakama name for Mount Adams, which is west of the type location for this series. The series originally was named the Pahto series.
National Cooperative Soil Survey
U.S.A.