LOCATION WATO               OR+WA
Established Series
Rev. DFA/RWL
11/2008

WATO SERIES


The Wato series consists of very deep, well drained soils that formed in loess over glaciofluvial deposits on uplands. Slopes are 0 to 35 percent. The mean annual precipitation is about 13 inches and the mean annual temperature is about 52 degrees F.

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

TYPICAL PEDON: Wato very fine sandy loam, cultivated. (Colors are for moist soil unless otherwise noted.)

Ap--0 to 7 inches; very dark brown (10YR 2/2) very fine sandy loam, dark grayish brown (10YR 4/2) dry; weak thin platy parting to weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many fine irregular pores; neutral (pH 6.6); abrupt smooth boundary. (5 to 9 inches thick)

A--7 to 13 inches; very dark brown (10YR 2/2) very fine sandy loam, dark grayish brown (10YR 4/2) dry; weak medium prismatic structure parting to weak coarse subangular blocky; soft, very friable, slightly sticky and slightly plastic; many very fine roots; common fine tubular pores; neutral (pH 6.6); abrupt smooth boundary. (5 to 11 inches thick)

Bw1--13 to 22 inches; brown (10YR 4/3) very fine sandy loam, brown (10YR 5/3) dry; weak coarse prismatic structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (0 to 17 inches thick)

Bw2--22 to 35 inches; brown (10YR 4/3) very fine sandy loam, brown (10YR 5/3) dry; weak coarse prismatic structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 10 percent gravel; neutral (pH 7.0); gradual smooth boundary. (8 to 12 inches thick)

Bw3--35 to 60 inches; brown (10YR 4/3) very fine sandy loam, pale brown (10YR 6/3) dry; very weak coarse prismatic structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; 15 percent gravel; neutral (pH 7.2); abrupt broken boundary.

TYPE LOCATION: Sherman County, Oregon, about 1,650 feet south and 2,280 feet west of the northeast corner of section 26, T. 3 N., R. 17 E.

RANGE IN CHARACTERISTICS: In most years the soils are usually moist but are dry for more than 80 to 100 consecutive days between depths of 8 and 24 inches within the four months following the summer solstice. The mean annual soil temperature is 49 to 56 degrees F. The solum ranges from 26 to more than 60 inches thick. The particle-size control section is 5 to 15 percent clay,0 to 10 percent gravel, and more than 15 percent coarser than very fine sand. Depth to bedrock is more than 60 inches. Depth to secondary calcium carbonate is 43 inches or more.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. Texture is fine sandy loam, very fine sandy loam, or silt loam. Organic matter content is 1 to 4 percent. Reaction is neutral to slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 2 to 5 moist, 4 to 6 dry and chroma of 2 to 4 moist and dry. Texture is very fine sandy loam, fine sandy loam or loam with 5 to 15 percent clay and 0 to 10 percent gravel. This horizon has weak medium to coarse prismatic or weak fine to medium subangular blocky structure. Organic matter content is less than 1 percent. Reaction is slightly alkaline to slightly acid.
The C horizon, when present, has hue of 10YR or 2.5Y, value of 4 to 6 moist, 4 to 8 dry and chroma of 3 or 4 moist and dry. Texture is very fine sandy loam, fine sandy loam or gravelly sandy loam with 10 to 15 percent clay and 0 to 25 percent gravel.
The 2Ck horizon, when present, is weakly cemented very gravelly loamy sand or very gravelly sand with 2 to 10 percent clay. It has 1 to 5 percent calcium carbonate equivalent.

COMPETING SERIES: These are the Anders, Brief, Chenoweth, Cleverly, Cushenbury, Duart, Hesslan, Knutsen, Newbon, Panamint, Patemos (T), Rimforest (T), and Siphonlake series.
Anders soils 20 to 40 inches to a lithic contact (basalt); dry for 90 to 105 consecutive days following the summer solstice
Brief soils 15 to 35 percent rock fragments in pscs
Chenoweth soils dry for 60 to consecutive 80 days following the summer solstice
Cleverly soils 15 to 35 percent rock fragments in pscs; dry for 60 consecutive days or more following the summer solstice
Cushenbury soils 20 to 40 inches to a paralithic contact (granite)
Duart soils 20 to 40 inches to a paralithic contact (sandstone)
Hesslan soils 20 to 40 inches to a paralithic contact (sandstone)
Knutsen soils 20 to 35 percent rock fragments in pscs; dry for 60 consecutive days or more following the summer solstice
Newbon soils 15 to 35 percent rock fragments in pscs
Panamint soils 20 to 40 inches to a paralithic contact (quartz monzonite); dry for 110 consecutive days following the summer solstice
Patemos soils 60 to 80 inches to a lithic contact (basalt); dry for 90 to 105 consecutive days following the summer solstice; lithologic discontinuity (3Btb) at a depth of 30 inches or more
Rimforest soils dry for 110 consecutive days following the summer solstice
Siphonlake soils 40 to 60 inches to a paralithic contact (stratified lacustrine deposits)

GEOGRAPHIC SETTING: Wato soils are on uplands and have slopes of 0 to 35 percent. Elevations are 300 to 1,500 feet. The soils formed in loess over glaciofluvial deposits. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 12 to 15 inches. The mean summer temperature is 69 degrees F. and the mean winter temperature is 37 degrees F. The mean annual temperature is 48 to 54 degrees F. The frost-free period is 110 to 170 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Anderly, Lickskillet, Nansene and Walla Walla soils. Anderly soils are 20 to 40 inches deep to bedrock and are on uplands. Lickskillet soils are less than 20 inches deep to bedrock and are on canyon slopes. Nansene and Walla Walla soils have coarse-silty control sections. Nansene soils are on north-facing slopes of uplands. Walla Walla soils are on loess hills.

DRAINAGE AND PERMEABILITY: Well-drained; moderately rapid permeability.

USE AND VEGETATION: These soils are used dominantly for production of grain crops. Other uses include hay, pasture and livestock grazing. Vegetation is mainly bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass and buckwheat.

DISTRIBUTION AND EXTENT: North-central Oregon and Eastern Washington. MLRA 8. The soils are inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Sherman County, Oregon, 1971.

REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon - the zone from 0 to 13 inches (Ap and A horizons).
Cambic horizon - the zone from 13 to 60 inches (Bw1, Bw2, and Bw3 horizons)
Particle-size control section - the zone from 10 to 40 inches.
The Wato soils were formerly included in the Walla Walla series as the very fine sandy loam type. The Juliaetta series description (Rev. AEK 3/4/46) is inadequate for comparison.


National Cooperative Soil Survey
U.S.A.