LOCATION WATERFLAT WAEstablished Series
TAXONOMIC CLASS: Ashy, glassy, mesic Aquandic Endoaquolls
TYPICAL PEDON: Waterflat ashy fine sandy loam - cropland, grass-alfalfa hay, on a 1 percent slope at an elevation of 2,700 feet. (The entire profile was moist when described on May 19, 1988. Colors are for moist soil unless otherwise stated. All textures are apparent field textures and spot plate reaction is used for pH values.)
Ap--0 to 10 inches; very dark grayish brown (10YR 3/2) ashy fine sandy loam, brown (10YR 5/3) dry; weak fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine, fine, and medium roots; few fine tubular pores; 10 percent sand-size ash, 0.5 to 2.0 mm in diameter; neutral (pH 6.6); gradual wavy boundary.
A1--10 to 20 inches; very dark grayish brown (10YR 3/2) ashy loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine roots; few very fine tubular and irregular pores; few fine distinct irregular dark yellowish brown (10YR 4/4) masses of iron accumulations scattered throughout the horizon; 15 percent sand-size ash, 0.5 to 2.0 mm in diameter; slightly alkaline (pH 7.5); gradual wavy boundary.
A2--20 to 30 inches; very dark grayish brown (10YR 3/2) ashy fine sandy loam, gray (10YR 5/1) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; few very fine and fine roots; common very fine tubular and few very fine irregular pores; few fine distinct irregular dark yellowish brown (10YR 4/4) masses of iron accumulations scattered throughout the horizon; 25 percent sand-size ash, 0.5 to 2.0 mm in diameter; slightly alkaline (pH 7.8); gradual wavy boundary. (Combined thickness of the A horizons is 24 to 40 inches)
Bk--30 to 43 inches; very dark grayish brown (10YR 3/2) ashy loam, light brownish gray (10YR 6/2) dry; massive; soft, very friable, nonsticky and slightly plastic; few very fine and fine roots; common very fine tubular and few fine irregular pores; common medium and fine faint irregular very dark brown (10YR 2/2) and few fine distinct irregular yellowish brown (10YR 5/6) masses of iron and manganese accumulations scattered throughout the horizon; 15 percent sand-size ash, 0.5 to 2.0 mm in diameter; common fine filaments and irregular concentrations of calcium carbonate, strongly effervescent; 4 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); gradual wavy boundary. (12 to 22 inches thick)
2BCk--43 to 60 inches; very dark grayish brown (10YR 3/2) stratified loam to coarse sand, light brownish gray (10YR 6/2) dry; massive; soft, very friable, nonsticky and slightly plastic; few very fine roots; common very fine tubular and few fine irregular pores; few fine faint irregular very dark brown (10YR 2/2) and few fine distinct irregular yellowish brown (10YR 5/6) masses of iron and manganese accumulations scattered throughout the horizon; 2 percent sand-size ash, 0.5 to 2.0 mm in diameter; 5 percent gravel; common fine filaments and irregular concentrations of calcium carbonate, strongly effervescent; 4 percent calcium carbonate equivalent; slightly alkaline (pH 7.8).
TYPE LOCATION: Douglas County, Washington; approximately 4.5 miles northeast of Waterville; about 1,400 feet west and 2,350 feet north of the southeast corner of section 36, T. 26 N., R. 22 E. (Latitude 47 degrees 42 minutes 24 seconds N, Longitude 120 degrees 00 minutes 43 seconds W)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 49 to 51 degrees F. These soils are usually moist but are dry in the moisture control section for 75 to 90 consecutive days following the summer solstice. The particle-size control section has moist bulk density of 1.05 to 1.30 g/cc, 30 to 60 percent volcanic glass, including 15 to 30 percent sand-size pumice, 0.5 to 2.0 mm. in diameter, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.15 to 0.35 percent, 15-bar water retention of 5 to 10 percent, 15 percent or more fine sand or coarser, 0 to 10 percent rock fragments, and an apparent field estimated clay content of 6 to 14 percent. Depth to distinct redox concentrations is 10 to 20 inches. Depth to the stratified BCk horizon is 40 to 60 inches. Depth to secondary carbonates and the mollic epipedon thickness is 24 to 40 inches.
The Ap horizon value is 4 or 5 dry and 2 or 3 moist. Chroma is 1, 2, or 3 dry and 1 or 2 moist. Reaction is moderately acid to neutral.
The A1 horizon value is 4 or 5 dry and 2 or 3 moist. Chroma is 1, 2, or 3 dry and 1 or 2 moist. Texture is ashy fine sandy loam, ashy loam, or ashy silt loam. Reaction is neutral or slightly alkaline.
The A2 horizon value is 4 or 5 and the chroma is 1, 2, or 3 dry. Texture is ashy fine sandy loam, ashy loam, or ashy silt loam. Reaction is neutral or slightly alkaline.
The Bk horizon hue is 10YR or 2.5Y. The value is 5 or 6 dry and 2 through 5 moist. The chroma is 1 or 2 dry or moist. The texture is ashy fine sandy loam, ashy silt loam, or ashy loam. The calcium carbonate equivalent is 1 to 8 percent. Reaction is slightly alkaline or moderately alkaline.
The 2BCk horizon hue is 10YR, 2.5Y, or 5Y. The value is 5, 6, or 7 dry and 3 through 6 moist. The chroma is 1 through 4 dry or moist. The textures of individual layers within this stratified horizon are silty clay loam, clay loam, silt loam, loam, very fine sandy loam, fine sandy loam, loamy fine sand, loamy sand, loamy very fine sand, sand, or coarse sand. The calcium carbonate equivalent is 1 to 10 percent. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Waterflat soils are in drainageways and swales on nonglaciated plateaus. Slopes are 0 to 3 percent. Waterflat soils formed in loess and volcanic ash over old alluvium. Elevation is 2,000 to 3,000 feet. The climate is characterized by warm, dry summers and cool, moist winters. Average annual precipitation is 12 to 15 inches. Average January air temperature is 26 degrees F., average July air temperature is 70 degrees F., and average annual air temperature is 47 to 49 degrees F. Frost-free season is 110 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Broadax, Dougville, Farmer, Mondovi, and Nemire soils. Broadax soils are on hills and have an argillic horizon. Dougville soils are on side slopes and toe slopes and Farmer soils are on ridge tops and hill slopes of uplands. Dougville and Farmer soils have an argillic horizon. Mondovi soils are on flood plains of intermittent streams and small perennial streams and are coarse-silty. Nemire soils are in drainageways and low areas, are well drained and lack redoximorphic features above 40 inches.
DRAINAGE AND PERMEABILITY: Poorly drained; very slow runoff; moderate permeability in the particle control section and moderately slow to very rapid permeability below the particle control section. They are subject to occasional flooding during spring runoff. They have a seasonally high water table at 12 to 18 inches depth for 3 to 5 months each year within the months of December through April.
USE AND VEGETATION: Waterflat soils are primarily used for wheat and barley production. Small areas are used for livestock grazing and wildlife habitat. The potential native vegetation is dominated by basin wildrye, iris, and Kentucky bluegrass with minor amounts of sedges, rushes and wild rose.
DISTRIBUTION AND EXTENT: North Central Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Washington, 1998.
REMARKS: Diagnostic features recognized in this pedon are a mollic epipedon from the surface to 30 inches, distinct high chroma masses of iron accumulation starting at 10 inches, 15 to 25 percent sand-size pumice, 0.5 to 2.0 mm in diameter from 10 to 43 inches with an estimated 30 to 60 percent volcanic glass, and a Bk horizon from 29 to 43 inches with 4 percent calcium carbonate equivalent over a stratified substratum. The control section is the zone from 10 to 40 inches (the A1, A2, and part of the Bk horizons).