LOCATION KENNEWICK               WA+OR

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

KENNEWICK SERIES

Landscape--hills
Landform--dissected terraces and terrace escarpments of remnant fans
Slope--0 to 60 percent
Parent material--lacustrine sediment; glacial outwash or flood deposits at a depth of 100 to 150 cm in some areas
Mean annual precipitation--about 180 mm
Mean annual air temperature--about 11 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--aridic
Soil temperature regime--mesic
Soil moisture subclass--xeric

TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Xeric Torriorthents

TYPICAL PEDON: Kennewick silt loam in an area of grassland (All textures are apparent field textures.)

A--0 to 5 cm; silt loam, grayish brown (10YR 5/2) dry, dark grayish brown (10YR 4/2) moist; weak thin platy structure; soft, friable, nonsticky and slightly plastic; many roots; few vesicular pores; strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary

C1--5 to 30 cm; silt loam, light gray (2.5Y 7/2) dry, grayish brown (2.5Y 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; finely laminated; common roots; few fine tubular pores; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary

C2--30 to 48 cm; silt loam, light gray (2.5Y 7/2) dry, grayish brown (2.5Y 5/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; thinly laminated; few roots; few fine tubular pores; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary

C3--48 to 81 cm; silt loam, light brownish gray (10YR 6/2) dry, dark gray (10YR 4/1) moist; massive; hard, firm, slightly sticky and slightly plastic; strong thin laminations; few fine tubular pores; disseminated and segregated mycelial lime; violently effervescent; strongly alkaline (pH 8.5); gradual wavy boundary

C4--81 to 102 cm; silt loam, light gray (2.5Y 7/2) dry, grayish brown (2.5Y 5/2) moist; massive; hard, firm, slightly sticky and slightly plastic; strong thin laminations; few fine tubular pores; disseminated and segregated mycelial lime; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary

C5--102 to 124 cm; silt loam, light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; hard, firm, slightly sticky and slightly plastic; moderate thin laminations; few fine tubular pores; disseminated and segregated mycelial lime; violently effervescent; strongly alkaline (pH 8.8); abrupt wavy boundary

C6--124 to 157 cm; silt loam, light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; violently effervescent; moderately alkaline (pH 8.3)

TYPE LOCATION: Benton County, Washington, about 30 m north and 120 m west of the intersection of Olympia Street and West 36th Avenue, south of Kennewick; in the SE1/4NE1/4NE1/4 of section 14, T. 8 N., R. 29 E., Willamette Meridian

RANGE IN CHARACTERISTICS:
Mean annual soil temperature at a depth of 50 cm--11 to 13 degrees C
Soil moisture--usually dry in all parts between depths of 10 and 30 cm
Particle-size control section--dominantly silt loam or very fine sandy loam; averages 2 to 10 percent clay and 5 to 15 percent fine sand or coarser
Upper 20 cm (mixed)--calcareous; pH of 7.9 to 9.0
Calcium carbonate equivalent--1 to 15 percent throughout

A horizon
Hue--10YR, 2.5Y
Value--5, 6, or 7 dry, 3 to 5 moist
Chroma--2 or 3 moist or dry
Reaction--7.4 to 8.4
Thickness--3 to 25 cm

C horizon
Hue--10YR, 2.5Y
Value--5 to 8 dry; 4, 5, or 6 moist
Chroma--1, 2, or 3 moist or dry
Texture below a depth of 100 cm in some pedons--very gravelly sand, extremely gravelly coarse sand
Combined thickness--125 to more than 150 cm

COMPETING SERIES:
Linoyer--10 to 18 percent clay in particle-size control section; no visible secondary carbonates in series control section
Pocatello--no hard and firm laminated silt loam above a depth of 100 cm; 5 to 15 percent hard krotovinas (cicada) in Bk horizon
Ritzcal--no hard and firm laminated silt loam above a depth of 100 cm in particle-size control section
Wheeler--15 to 23 percent calcium carbonate in particle-size control section

GEOGRAPHIC SETTING:
Elevation--90 to 490 m
Climate--arid; warm, dry summers; cool, moist winters
Mean annual precipitation--150 to 230 mm
Mean January air temperature--about -2 degrees C
Mean July air temperature--about 22 degrees C
Mean annual air temperature--about 10 to 12 degrees C
Frost-free season--130 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Finley--on terraces; loamy-skeletal particle-size class
Royal, Warden--on terraces; cambic horizon
Taunton--on terraces; duripan
Wahluke--on terraces; weakly cemented lenses in particle-size control section

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

USE AND VEGETATION:
Use--irrigated crop production, domestic livestock grazing
Native vegetation--bluebunch wheatgrass, needle and thread, Wyoming big sagebrush, balsamroot, Sandberg bluegrass, spiny hopsage, winterfat, Indian ricegrass, bottlebrush squirreltail

DISTRIBUTION AND EXTENT: South-central Washington; MLRA 7; moderate extent

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

SERIES ESTABLISHED: Benton County, Washington; 1971

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Free carbonates--throughout profile

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National Cooperative Soil Survey
U.S.A.