LOCATION WALLA WALLA             WA+OR

Established Series
Rev. RJE/TLA/RWL
09/2019

WALLA WALLA SERIES

Landscape--hills, plateaus
Landform--hillslopes, structural benches
Slope--0 to 65 percent
Parent material--loess
Mean annual precipitation--360 mm
Mean annual air temperature--11 degrees C
Depth class--deep, very deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Typic Haploxerolls

TYPICAL PEDON: Walla Walla silt loam, cultivated

Ap--0 to 15 cm; silt loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; neutral (pH 6.8); abrupt smooth boundary

A--15 to 33 cm; silt loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; neutral (pH 6.8); clear smooth boundary

AB--33 to 46 cm; silt loam, brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to weak subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine tubular pores; slightly alkaline (pH 7.4); clear wavy boundary

Bw--46 to 114 cm; silt loam, brown (10YR 5/3) dry, brown (10YR 4/3) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; common roots; common very fine tubular pores; slightly alkaline (pH 7.6); gradual wavy boundary

Bk1--114 to 140 cm; silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few roots; few very fine tubular pores; weakly calcareous with lime in old root channels; moderately alkaline (pH 8.3); gradual wavy boundary

Bk2--140 to 165 cm; silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few roots; few very fine tubular pores; strongly calcareous with disseminated lime; strongly alkaline (pH 8.8)

TYPE LOCATION: Adams County, Washington; about 490 m north and 30 m west of the southeast corner of section 31, T. 20 N., R. 37 E.

RANGE IN CHARACTERISTICS:
Moisture control section--usually moist, but dry in all parts 90 to 105 consecutive days between depths of 10 to 30 cm following summer solstice
Depth to basalt--100 to 150 cm or more
Depth to cemented substratum in some pedons--100 to 150 cm
Depth to secondary carbonates--110 to 150 cm or more
Thickness of mollic epipedon--25 to 50 cm
Mean annual soil temperature--9 to 13 degrees C
Content of clay in particle-size control section--10 to 18 percent

Ap horizon
Thickness--12 to 18 cm

A horizon
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Reaction--6.6 to 7.8
Thickness--13 to 18 cm

AB horizon (where present)
Value--4 or 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Reaction--6.6 to 7.8
Thickness--0 to 25 cm

Bw horizon
Value--5 or 6 dry, 3 or 4 moist
Chroma--3 or 4 moist or dry
Structure--subangular blocky, prismatic
Reaction--6.6 to 7.8
Thickness--41 to 99 cm

Bk horizon
Value--5 to 7 dry, 3 to 5 moist
Chroma--2 to 4 dry or moist
Structure--massive, prismatic
Reaction--7.4 to 9.0
Combined thickness--greater than 25 cm

COMPETING SERIES:
Anderly--50 to 100 cm (moderately deep) to a lithic contact (basalt); dry 60 to 90 consecutive days following summer solstice

GEOGRAPHIC SETTING:
Elevation--45 to 795 m
Climate--semiarid; warm, dry summers; cool, moist winters
Mean annual precipitation--310 to 380 mm
Mean January air temperature--about -1 degree C
Mean July air temperature--about 22 degrees C
Mean annual air temperature--about 9 to 12 degrees C
Frost-free season--110 to 170 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Alpowa--loamy-skeletal particle-size class; on alluvial fans, hills, and plateaus
Anderly, Anders--50 to 100 cm (moderately deep) to a lithic contact (basalt); on plateaus, benches, and channeled scabland
Benge--coarse-loamy over sandy or sandy-skeletal particle-size class; on terraces
Chard--coarse-loamy particle-size class; on terraces
Kuhl--25 to 50 cm (shallow) to a lithic contact (basalt); on canyon slopes
Nansene--on steep, north-facing slopes; mollic epipedon 75 to 100 cm thick
Oliphant--zone of calcium carbonate accumulation at a depth of 51 to 112 cm; on hillslopes and plateaus
Onyx--on associated flood plains; mollic epipedon 50 to 100 cm thick or more
Spofford--natric horizon; on plateaus and hills
Walvan--dominantly volcanic ash; on uplands

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high

USE AND VEGETATION:
Use--nonirrigated and irrigated crop production, some livestock grazing
Native vegetation--bluebunch wheatgrass, Sandberg bluegrass, big bluegrass, arrowleaf balsamroot, western yarrow, sagebrush

DISTRIBUTION AND EXTENT: Southeastern Washington and northeastern Oregon; MLRA 8; large extent

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Walla Walla County, Washington; 1902

REMARKS:
Diagnostic horizons and other features in this pedon
*Mollic epipedon--zone from the surface to a depth of 46 cm
*Cambic horizon--zone from 46 to 114 cm
*Carbonate accumulation--zone from 114 to 150 cm
*Particle-size control section--zone from 25 to 100 cm

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National Cooperative Soil Survey
U.S.A.