LOCATION PROSSER                 WA+OR

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

PROSSER SERIES

Landscape--plateaus, hills
Landform--structural benches, hillslopes
Slope--0 to 60 percent
Parent material--loess and glaciofluvial sediment and a minor amount of volcanic ash over basalt
Mean annual precipitation--about 200 mm
Mean annual air temperature--about 10 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--aridic
Soil temperature regime--mesic
Soil moisture subclass--xeric

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Xeric Haplocambids

TYPICAL PEDON: Prosser very fine sandy loam in an area of grassland

A--0 to 10 cm; very fine sandy loam, grayish brown (10YR 5/2) dry, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many roots; neutral (pH 7.2); abrupt smooth boundary

Bw1--10 to 38 cm; very fine sandy loam, brown (10YR 5/3) dry, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many roots; common very fine tubular pores; slightly alkaline (pH 7.6); clear wavy boundary

Bw2--38 to 61 cm; very fine sandy loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; many roots; common very fine tubular pores; moderately alkaline (pH 8.0); clear wavy boundary

Bk--61 to 76 cm; very fine sandy loam, light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; many roots; many very fine tubular pores; slightly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary

2R--76 cm; basalt; discontinuous coatings of lime and silica

TYPE LOCATION: Adams County, Washington, about 3 km northwest of Othello; about 150 m south and 30 m east of the northwest corner of section 28, T. 16 N., R. 29 E., Willamette Meridian

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--10 to 13 degrees C
Soil moisture--usually dry in all parts between depths of 10 and 30 cm following summer solstice, moist in winter and spring
Depth to Bk horizon (where present)--25 to 75 cm
Depth to lithic contact--50 to 100 cm
Content of clay--5 to 12 percent
Content of sand coarser than very fine sand, including gravel, in particle-size control section--15 to 30 percent

A horizon
Value--5 or 6 dry, 3 or 4 moist
Chroma--2 to 4 dry or moist
Reaction--6.6 to 7.8
Thickness--8 to 15 cm

Bw horizon
Value--5 or 6 dry, 3 or 4 moist
Chroma--2 to 4 dry or moist
Texture--silt loam, very fine sandy loam
Reaction--7.4 to 8.4
Combined thickness--18 to 66 cm

Bk horizon (where present)
Value--5 to 7 dry, 3 to 5 moist
Chroma--2 to 4 dry or moist
Texture--silt loam, very fine sandy loam
Calcium carbonate equivalent--1 to 15 percent
Gravel or cobble content--0 to 15 percent
Lime accumulation--thin cap on top of bedrock in some pedons
Thickness--0 to 30 cm

COMPETING SERIES:
Bijorja--50 to 100 cm (moderately deep) to a paralithic contact (granodiorite)
Chedehap, Clems, Drewsey, Haybourne, Heist, Rebel, Royal, Scooteney--no lithic contact within a depth of more than 150 cm
Irrigon--50 to 100 cm (moderately deep) to a paralithic contact (tuffaceous sandstone)
McClenden--more than 114 cm (deep, very deep) to a lithic contact (mixed sources)
Vining--more than 30 percent sand coarser than very fine sand, including gravel, in particle-size control section
Wiehl--50 to 100 cm (moderately deep) to a paralithic contact (sandstone)

GEOGRAPHIC SETTING:
Elevation--90 to 730 m
Climate--hot, dry summers; cool, moist winters
Mean annual precipitation--150 to 250 mm
Mean January air temperature--about -2 degrees C
Mean July air temperature--about 22 degrees C
Mean annual air temperature--about 9 to 12 degrees C
Frost-free season--135 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Burke--on uplands; 50 to 100 cm (moderately deep) to a duripan
Ephrata--on terraces; coarse-loamy over sandy or sandy-skeletal particle-size class
Koehler--on terraces; sandy particle-size class; 50 to 100 cm (moderately deep) to a duripan
Quincy--on dunes and terraces; sandy particle-size class; no lithic contact within a depth of more than 150 cm
Shano--on uplands; no lithic contact within a depth of more than 150 cm
Starbuck--on benches; 30 to 50 cm (shallow) to a lithic contact (basalt)
Warden--on terraces; no lithic contact within a depth of 100 cm or more

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

USE AND VEGETATION:
Use--mainly livestock grazing and irrigated crop production
Native vegetation--bluebunch wheatgrass, Sandberg bluegrass, big sagebrush

DISTRIBUTION AND EXTENT: Southeastern and south-central Washington and north-central Oregon; MLRA 7; moderate extent

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

SERIES ESTABLISHED: Benton County, Washington; 1916

REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Cambic horizon--zone from 10 to 61 cm
*Depth to lithic contact--76 cm
*Particle-size control section--zone from 25 to 76 cm

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National Cooperative Soil Survey
U.S.A.