LOCATION NECONDA WAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Calcic Pachic Argixerolls
TYPICAL PEDON: Neconda silty clay loam - cultivated on 3 percent south facing slope at an elevation of 3,280 feet. (Colors are for dry soil unless otherwise noted)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) silty clay loam, black (10YR 2/1) moist; moderate fine and medium granular structure; hard, firm, sticky and plastic; many very fine roots; common very fine irregular pores; neutral (pH 6.6);' abrupt smooth boundary. (6 to 9 inches thick)
A--8 to 12 inches; grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist, common medium very dark brown (10YR 2/2) moist, coatings on ped faces; moderate medium and coarse subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; common very fine irregular pores; neutral (pH 6.8); clear wavy boundary. (3 to 7 inches thick)
Bt1--12 to 18 inches; brown (10YR 5/3) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard,firm, sticky and plastic; common very fine roots; common very fine tubular pores; many thin stress cutans and clay films on faces of peds; and clay films lining some pores; neutral (pH 7.0); clear wavy boundary. (3 to 8 inches thick)
Bt2--18 to 27 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine roots; common very fine tubular pores; continuous moderately thick stress cutans and clay films on faces of peds and clay films lining some pores; 5 percent pebbles; neutral (pH 7.0); clear wavy boundary. (3 to 10 inches thick)
Bt3--27 to 34 inches; brown (10YR 5/3) gravelly clay; dark yellowish brown (10YR 4/4) moist; ped faces, dark brown (7.5YR 3/3) moist; strong, medium angular blocky structure; extremely hard, very firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; continuous thick stress cutans on faces of peds; 15 percent pebbles and 5 percent cobbles; neutral (pH 7.0); abrupt wavy boundary. (0 to 8 inches thick)
2Bk--34 to 37 inches; very pale brown (10YR 7/3) very cobbly silt loam, brownish yellow (10YR 6/6) moist; massive; hard, firm, slightly sticky and slightly plastic; few very fine roots; common very fine irregular pores; disseminated lime; violently effervescent; 15 percent pebbles and 25 percent cobbles; moderately alkaline (pH 8.4); abrupt irregular boundary. (2 to 10 inches thick)
3R--37 inches; basalt.
TYPE LOCATION: Asotin County, Washington; about 5 miles east of Anatone; 800 feet west and 2,200 feet south of the northeast corner of sec. 34, T. 8 N., R. 46E.
RANGE IN CHARACTERISTICS: The depth to a calcic horizon is 20 to 36 inches. Depth to basalt is 22 to 40 inches. The mean annual soil temperature is about 48 degrees F. The soils are usually moist, but are dry in all parts between depth of 4 and 12 inches for 60 to 75 consecutive days during summer and fall. The family control section has 35 to 50 percent clay. The mollic epipedon is 20 to 30 inches thick and includes all or part of the argillic horizon.
The A horizon has value of 3 or 4 dry, 2 or 3 moist, and chroma of 1 or 2 dry or moist. Reaction is slightly acid or neutral.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 through 4 dry or moist. The upper part is silty clay loam, silty clay, or clay. The lower part of Bt horizon is gravelly clay or cobbly clay. The Bt horizon is neutral or mildly alkaline throughout.
The 2Bk horizon has value of 6 through 8 dry, 4 through 6 moist, and chroma of 2 or 3 dry and 3 through 6 moist. It is silt loam, loam, or clay loam and is very cobbly very gravelly or gravelly. A thin Btk horizon is in some pedons just above the fractured basalt. The Bk horizon is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Avon, McMurdie, and Tub series. These soils are all more than 40 inches deep to a lithic contact.
GEOGRAPHIC SETTING: Neconda soils are on basalt plateaus and have slopes of 3 to 30 percent. They formed in loess and slope alluvium from weathered basalt. Elevation ranges from 3,000 to 3,600 feet. Summers are warm and dry and winters are cool and moist. The average annual precipitation ranges from 17 to 19 inches. The mean annual air temperature is about 46 degrees F. Frost-free season is 115 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: They are the Gwinly, Mallory, Powwahkee, Rockly, and Ferdinand soils. Gwinly and Rockly soils have a lithic contact at a depth of less than 20 inches. Mallory and Ferdinand soils are clayey-skeletal. Powwahkee soils are more than 40 inches deep to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff, slow permeability.
USE AND VEGETATION: Used for cropland and wildlife habitat. The principle crops are small grains and grass. Native vegetation is Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, and rose.
DISTRIBUTION AND EXTENT: Southeast Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Asotin County, Washington, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 27 inches, an argillic horizon from 12 to 34 inches, a calcic horizon from 34 to 37 inches, and a lithic contact at 37 inches.