LOCATION SPRAUER WAEstablished Series
TAXONOMIC CLASS: Ashy, glassy, mesic Vitritorrandic Durixerolls
TYPICAL PEDON: Sprauer ashy fine sandy loam - cropland, wheat stubble, on a 2 percent slope at an elevation of 2,630 feet. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures and spot plate reaction is used for pH values.)
Ap--0 to 8 inches; grayish brown (10YR 5/2) ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; few very fine tubular and common very fine irregular pores; 25 percent sand-size ash, 0.5 to 2.0 mm. in diameter and 3 percent duripan fragments, 2 to 75 mm. in diameter; neutral (pH 7.2); abrupt smooth boundary. (7 to 9 inches thick)
Bw--8 to 22 inches; brown (10YR 5/3) ashy fine sandy loam, dark brown (10YR 3/3) moist; moderate very coarse subangular blocky structure parting to moderate coarse subangular blocky; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; common very fine tubular and common very fine irregular pores; 20 percent sand-size ash, 0.5 to 2.0 mm. in diameter and 3 percent duripan fragments, 2 to 75 mm. in diameter; slightly alkaline (pH 7.7); clear wavy boundary. (9 to 17 inches thick)
Bk--22 to 30 inches; brown (10YR 5/3) ashy fine sandy loam, dark brown (10YR 3/3) moist; moderate coarse and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; common very fine tubular and common very fine and few fine irregular pores; 20 percent sand-size ash, 0.5 to 2.0 mm.in diameter and 5 percent duripan fragments, 2 to 75 mm. in diameter; disseminated carbonates and few fine filaments of calcium carbonate in pores, violently effervescence; 7 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 15 inches thick)
2Bkqm--30 to 40 inches; white (10YR 8/1) indurated duripan, very pale brown (10YR 8/3) moist, few fine and medium irregular patches of pale brown (10YR 6/3) scattered throughout the matrix, yellowish brown (10YR 5/4) moist; massive; very hard and very firm; common very fine roots in the upper portions of duripan fractures; common angular and subangular basalt pebbles encased within the duripan; fractured duripan plates average 4 to 7 inches in width and 1.5 to 2.5 inches in thickness.
3R--40 inches; basalt.
TYPE LOCATION: Douglas County, Washington; approximately 2 miles northwest of Withrow; about 300 feet north and 2,200 feet east of the southwest corner of section 20, T. 26 N., R. 24 E. (Latitude 47 degrees 43 minutes 46 seconds N, Longitude 119 degrees 50 minutes 46 seconds W)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 52 degrees F. These soils are usually dry in the moisture control section for more than half the cumulative time when the soil temperature is above 41 degrees F. The mollic epipedon is 7 to 15 inches thick. The solum above the duripan has an estimated moist bulk density of 1.10 to 1.35 g/cc, volcanic glass content of 30 to 60 percent, including 15 to 30 percent pumiceous sand, 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 0.40 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 5 to 14 percent. Depth to the indurated duripan is 20 to 40 inches. Basalt bedrock underlies the indurated duripan at depths of 30 to 60 inches.
The Ap horizon chroma is 2 or 3 dry or moist.
The Bw horizon is ashy fine sandy loam or ashy sandy loam. Reaction is neutral or slightly alkaline.
The Bk horizon value is 5 or 6 dry and 3 or 4 moist. It is ashy fine sandy loam, ashy loam, or ashy silt loam. It has 1 to 8 percent calcium carbonate equivalent. Reaction is slightly alkaline or moderately alkaline.
The 2Bkqm horizon value is 6 to 8 dry and 5 to 8 moist. The chroma is 1 to 3 dry and 2 to 4 moist. The indurated duripan is cemented with silica and calcium carbonate, it is 4 to 24 inches thick, and is fractured with average duripan plates measuring 4 to 14 inches in width and 1 to 4 inches in thickness.
COMPETING SERIES: This is the Wellsdam series. Wellsdam soils have a weakly cemented duripan and are over dense glacial till.
GEOGRAPHIC SETTING: Sprauer soils are on nonglaciated plateaus. Slopes are 0 to 30 percent. Sprauer soils formed in loess and volcanic ash. Elevation is 2,000 to 2,800 feet. The climate is characterized by warm, dry summers and cool, moist winters. Average annual precipitation is 9 to 12 inches. Average January air temperature is about 27 degrees F., average July air temperature is about 71 degrees F., and average annual air temperature is 48 to 50 degrees F. Frost-free season is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aarup, Deercut, Kester, Toler, and Whiteye soils. Aarup soils are on summits, hill slopes, and toe slopes on plateaus and are shallow to thick indurated duripan. Deercut soils are on side slopes and toe slopes of uplands on plateaus and have an argillic horizon. Kester soils are on intermittent stream bottoms and side drainages and are moderately deep to basalt bedrock. Toler soils are on uplands and have an argillic horizon. Whiteye soils are on uplands and are shallow to thick indurated duripan.
DRAINAGE AND PERMEABILITY: Well drained; very slow to medium runoff; moderate permeability above the duripan.
USE AND VEGETATION: Sprauer soils are primarily used for dryland wheat and barley production. Small areas are used for livestock grazing or wildlife habitat. The potential native vegetation is bluebunch wheatgrass, Sandberg bluegrass, Wyoming big sagebrush and arrowleaf balsamroot.
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 and horizons recognized in this pedon are a mollic epipedon from the surface to 8 inches, a cambic horizon from 8 to 22 inches, a Bk horizon from 22 to 30 inches with a field estimated calcium carbonate equivalent of 7 percent. The profile from the surface to 30 inches (duripan) has an estimated volcanic glass content of 30 to 60 percent, including 20 to 25 percent sand-size ash 0.5 to 2.0 mm in size. The control section is the zone from 10 to 30 inches (part of the Bw, and the Bk horizons).
ADDITIONAL DATA: The calcium carbonate equivalent test done on the Bk horizon was run in the survey office using a standard calcimeter.