LOCATION STUBBLEFIELD WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Cambidic Durixerolls
TYPICAL PEDON: Stubblefield stony loam - on a 10 percent southeast facing slope under native shrubs and grasses at an elevation of 1,640 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 9 inches; grayish brown (10YR 5/2) stony loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine, common fine roots; few fine interstitial pores; 10 percent pebbles and 5 percent stones; neutral (pH 7.0); clear wavy boundary. (8 to 12 inches thick)
Bw--9 to 24 inches; pale brown (10YR 6/3) very gravelly loam, dark brown (10YR 4/3) moist; weak medium subangular blocky structure;slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few fine interstitial pores; 30 percent pebbles, 10 percent cobbles, and 5 percent stones; neutral (pH 7.3); abrupt smooth boundary. (12 to 30 inches thick)
Bkqm--24 to 28 inches; light brownish gray (2.5Y 6/2) lime-silica strongly cemented duripan which crushes to very cobbly sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; very hard, very firm, nonsticky and nonplastic; few very fine roots matted at top of duripan; few fine and very fine tubular pores; 25 percent pebbles, 15 percent cobbles, and 10 percent stones; a laminar cap less than 1 mm. thick covers the upper duripan surface and has many distinct pinkish white (7.5YR 8/2) silica coatings on the laminar cap, pinkish gray (5YR 6/2) moist; common distinct calcium carbonate coatings on the laminar cap and disseminated carbonates below, strongly effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (1 to 10 inches thick)
2Bkd--28 to 60 inches; light brownish gray (2.5Y 6/2) dense glacial till that crushes very cobbly sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; hard, firm, nonsticky and nonplastic; few very fine interstitial and tubular pores; 30 percent cobbles, 10 percent pebbles and 5 percent stones; few fine filaments and soft masses of calcium carbonate plus disseminated carbonates in the matrix and few fine distinct carbonate coatings on rock fragments, strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Colville Indian Reservation, Okanogan County, Washington; about 16 miles east of the town of Bridgeport; 1,650 feet north and 700 feet east of the southwest corner sec. 18, T. 30 N., R. 28 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 53 degrees F. These soils are usually dry in all parts between a depth of 8 and 24 inches for one-half to three-fourths of the time when the soil temperature is greater than 41 degrees F. The mollic epipedon is 8 to 15 inches thick and has 2 to 15 percent volcanic glass and 0.15 to 0.40 percent acid oxalate extractable aluminum plus one half the iron. The control section has 5 to 14 percent clay. Depth to a duripan is 20 to 40 inches. Some pedons have a zone of calcium carbonate accumulation directly above the duripan.
The A horizon has chroma of 2 or 3 dry and moist. Reaction is slightly acid to slightly alkaline.
The Bw horizon has value of 5 or 6 dry, 3 or 4 moist, and chroma of 2 or 3 dry or moist. It is loam, fine sandy loam, or sandy loam and is 35 to 50 percent rock fragments, including 15 to 35 percent pebbles, 5 to 30 percent cobbles, and 0 to 10 percent stones. The Bw horizon is neutral or slightly alkaline and has weak fine or medium subangular blocky structure.
The Bkqm horizon has hue of 10YR or 2.5Y, value of 5 through 7 dry, 3 through 5 moist, and chroma of 1 or 2 dry or moist. It is weakly or strongly cemented and crushes to fine sandy loam, sandy loam, or coarse sandy loam. It is 15 to 40 percent pebbles, 5 to 30 percent cobbles, and 0 to 10 percent stones. It is moderately alkaline to strongly alkaline.
The 2Bkd horizon has a hue of 10YR or 2.5Y. Value is 5 through 7 dry and 4 through 6 moist. Chroma is 1 or 2 dry or moist. Texture is sandy loam or fine sandy loam with 10 to 40 percent pebbles, 5 to 35 percent cobbles, and 0 to 10 percent stones. Reaction is slightly alkaline or strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Stubblefield soils are on ground moraines. These soils formed in glacial till dominantly from basalt with an admixture of loess and a minor amount of volcanic ash. Slopes are 0 to 70 percent. Elevations are 1,000 to 2,800 feet. The climate is semiarid with warm, dry summers and cool, moist winters. The average annual precipitation is 9 to 12 inches. The mean January temperature is about 25 degrees F, the mean July temperature is about 74 degrees F, and the mean annual air temperature is about 50 degrees F. The frost-free season is 130 to 185 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Heytou, Malott, Peshastin, Pogue, Skaha, and Touhey soils. Heytou and Touhey soils are on till plains. Heytou soils are greater than 60 inches to duripan. Touhey soils are ashy over loamy. Malott soils are on till plains and glaciated hills, are 40 to 60 inches to duripan and have 5 to 30 percent rock fragments in the control section. Peshastin soils are on moraines and terraces, are greater than 60 inches to duripan, and have acid igneous rock fragments predominating in the control section. Pogue and Skaha soils are on terraces and terrace escarpments. Pogue soils are 20 to 40 inches to sandy-skeletal outwash. Skaha soils are sandy-skeletal and hve an ochric epipedon.
DRAINAGE AND PERMEABILITY: Well drained, runoff is very slow to very rapid; permeability is moderate above the duripan.
USE AND VEGETATION: Livestock grazing, dryland grain production, recreation, wildlife and watershed are the principal uses. Potential uses are irrigated orchards and irrigated hay and pasture. Native vegetation is bluebunch wheatgrass, needleandthread, Sandberg bluegrass, silky lupine, arrowleaf balsamroot, hood phlox, big sagebrush and threetip sagebrush.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Colville Indian Reservation, Okanogan County, Washington; 1987.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from the surface to 9 inches, a cambic horizon from 9 to 24 inches, and a duripan at 24 inches.
ADDITIONAL DATA: Partial NSSL lab data is available for several other pedons, NSSL pedon number 89P213 and 89P216.