LOCATION GARFIELD WA+IDEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Mollic Haploxeralfs
TYPICAL PEDON: Garfield silty clay loam - cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 8 inches; brown (10YR 5/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine granular structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; many fine pores; slightly acid (pH 6.4); abrupt smooth boundary. (5 to 8 inches thick)
Bt1--8 to 27 inches; yellowish brown (10YR 5/4) silty clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic parting to strong fine angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; many very fine and fine roots; few very fine and many medium pores; faint continuous clay films on faces of peds; very dark brown (10YR 2/2) manganese coatings on faces of peds; common fine iron-manganese concretions; neutral (pH 6.6); clear wavy boundary. (18 to 25 inches thick)
Bt2--27 to 48 inches; light yellowish brown (10YR 6/4) silty clay loam, dark brown (10YR 4/3) moist; moderate coarse prismatic parting to strong fine angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few very fine and fine roots; common very fine pores and many medium tubular pores; faint continuous clay films on faces of peds; very dark brown (10YR 2/2) moist; manganese coatings on faces of peds; common fine iron-manganese concretions; slightly alkaline (pH 7.6); abrupt wavy boundary. (18 to 22 inches thick)
Bt3--48 to 60 inches; light yellowish brown (10YR 6/4) silty clay loam, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic parting to strong fine angular blocky structure; very hard, very firm, sticky and plastic; few fine roots; few fine pores; faint continuous clay films on faces of peds; few very dark brown (10YR 2/2) moist manganese coatings on faces of peds; few fine iron-manganese concretions; neutral (pH 6.6).
TYPE LOCATION: Whitman County, Washington; about 1,900 feet west and 1,900 feet south of the northeast corner of section 30, T. 15 N., R. 45 E.
RANGE IN CHARACTERISTICS: The mean annual temperature at depth of 20 inches ranges from 48 to 52 degrees F. The soils are dry for 70 to 90 consecutive days in all parts between 4 and 12 inches deep. Depth to the base of the argillic is 40 inches or more.
The Ap horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, and chroma of 2 or 3 dry, 1 to 3 moist. Reaction is slightly acid or neutral. Texture is silty clay loam or silt loam. It has an estimated volcanic glass content of 0 to 5 percent.
The Bt1 and Bt2 horizons have hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 to 6 moist, and chroma of 3 to 6 dry, 3 or 4 moist. Texture is silty clay loam or silty clay with 35 to 45 percent clay. It has a volcanic glass content of 0 to 5 percent. It has moderate or strong structure. Cracks 1/4 to 1/2 inch wide may occur during the summer when soil becomes very dry. Clay films on the vertical peds range from many distinct to common prominent. This horizon has few to common fine manganese concretions and few to common very dark brown (10YR 2/2) to black (2.5YR 2.5/1) moist manganese staining on faces of peds. Calcium carbonate accumulates along fractured planes in the lower part of the Bt2 horizon in some pedons.
The Bt3 horizon has value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 to 6 dry, 3 or 4 moist. Texture is silt loam or silty clay loam with 25 to 40 percent clay. The structure is weak or moderate medium prismatic parting to moderate or strong subangular blocky. Reaction is neutral to moderately alkaline.
COMPETING SERIES: These are the Monita and Secca series. The Monita soils are 40 to 60 inches to bedrock. Secca soils have 2 to 30 percent coarse fragments in the upper 20 inches of the argillic horizon and have mean annual soil temperature of 56 to 58 degrees F.
GEOGRAPHIC SETTING: These soils occur at elevations of 1,900 to 3,000 feet on ridgetops and loess hills on plateaus. Slopes are 0 to 40 percent. These soils formed in pre-Bull-Lake loess, with mixture of post Pinedale loess in the surface layer. The climate is characterized by warm, dry summers and cool, moist winters. The average annual precipitation of 18 to 23 inches. The average January temperature is 28 degrees F., average July temperature is 68 degrees F., and the average annual temperature is 47 to 49 degrees F. The frost-free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caldwell, Latah, Naff, Palouse, Tilma, and Thatuna soils. Caldwell soils have mollic epipedons more than 20 inches thick, are somewhat poorly drained, and are in drainageways. Latah and Tilma soils have mollic epipedons, an albic horizon above the argillic horizon and are in drainageways. Palouse and Thatuna soils have mollic epipedons more than 20 inches thick and are on loess hills. Naff soils have a mollic epipedon, are fine-silty and are on loess hills.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: These soils are used for production of small grains, peas, and lentils and for legume grass for hay. Native vegetation consists of Idaho fescue, bluebunch wheatgrass, arrowleaf balsamroot, western yarrow, phlox, and wild rose brush.
DISTRIBUTION AND EXTENT: Throughout the eastern part of Whitman County, Spokane County, in Washington; Benewah, Nez Perce, and Latah Counties in Idaho. Small in extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Whitman County, Washington, 1942.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon (mollic subgroup feature) - the zone from 0 to 8 inches meeting all criteria for a mollic epipedon except depth (Ap horizon)
Argillic horizon - the zone from 8 to 60 inches (Bt1, Bt2, and Bt3 horizons)
Particle-size control section - the zone from 8 to 28 inches (Bt1 and part of the Bt2 horizon)
The Garfield soils were formerly classified as Prairie soils.
The classification of this seies has been revised as of 5/00 with the addition of a superactive CEC activity class based on revision of Soil Taxonomy.
ADDITIONAL DATA: Riverside Soil Survey laboratory S72 Wa 38-11-1, S73 Wa 38-35-1, S73 Wa 38-37-(1 to 3), S65 Wa 38-8-1; Lincoln NSSL, S85WA075-012.