LOCATION SCHUMACHER         WA+ID

SCHUMACHER SERIES

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Argixerolls

TYPICAL PEDON: Schumacher silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many fine roots; neutral (pH 6.8); abrupt smooth boundary. (6 to 10 inches thick)

A--6 to 12 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many roots; many fine pores; neutral (pH 6.8); gradual wavy boundary. (0 to 10 inches thick)

AB--12 to 19 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2); moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common roots; many fine pores; 5 percent quartzite gravel; neutral (pH 6.8); abrupt wavy boundary. (4 to 10 inches thick)

Bt1--19 to 31 inches; brown (7.5YR 4/4) silty clay loam, dark brown (7.5YR 3/4) moist; strong fine and medium angular blocky structure; very hard, very firm, sticky, plastic; few roots; few medium pores; thick continuous clay films on peds; 15 percent quartzite gravel; neutral (pH 6.8); clear wavy boundary. (6 to 10 inches thick)

Bt2--31 to 37 inches; brown (7.5YR 5/4) silty clay loam, brown (7.5YR 4/4) moist; strong fine and medium blocky structure; very hard, very firm, sticky, plastic; few fine roots; few medium pores; thick continuous clay films on peds; 10 percent quartzite gravel neutral (pH 6.6); clear wavy boundary. (8 to 10 inches thick)

Bt3--37 to 43 inches; brown (7.5YR 5/4) silty clay loam, brown (7.5YR 4/4); moist; moderate fine subangular blocky structure; very hard, very firm, sticky, plastic; very few fine roots; many very fine pores; thin continuous clay films on peds; 12 percent quartzite gravel; neutral (pH 6.6).

R--43 inches; metasediments.

TYPE LOCATION: Whitman County, Washington; 1,500 feet south and 1,800 feet [s1]east of the NW corner of section 19, T.19N., R.44E. Latitude 47 degrees, 8 minutes, 1.5 seconds North; Longitude 117 degrees, 18 minutes, 54.5 seconds West; NAD 83. USGS Rosalia, WA topographic quadrangle.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 47 to 52 degrees F.
Depth to a lithic contact 40 to 60 inches
Moisture control section - These soils are usually moist, but are dry 45 to 60 consecutive days in the moisture control section following the summer solstice.
Clay content in the particle-size control section is 25 to 35 percent
Rock fragments 5 to 30 percent in the particle-size control section
Thickness of the mollic epipedon - 10 to 20 inches.
Ped and void surface features (Bt horizons) - thin continuous to thick continuous clay films. Some peds have graying or striping and some contain few relict manganese shot or coatings.

Ap and A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 or 2, moist or dry
Clay content 10 to 25 percent
Structure grade weak or moderate[s2]
Gravel content 0 to 20 percent

AB horizon
Hue - 10YR
Value 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3, moist or dry
Clay content - 13 to 25 percent
Texture silt loam, loam
Gravel content 0 to 25 percent
Cobble content 0 to 15 percent
Total rock fragment content 0 to 30 percent

Bt1 and Bt2 horizons
Hue - 7.5YR or 10YR
Value - 4 to 6 dry, 3 or 4 moist
Chroma - 3 or 4 moist or dry
Clay content 18 to 35[s3] percent
Texture - silty clay loam, clay loam, silt loam, loam
Gravel content 0 to 30 percent
Cobble content 0 to 15 percent
Total rock fragment content - 0 to 30 percent

Bt3 horizon
Hue - 7.5YR or 10YR
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 3 or 4 moist or dry
Clay content 15 to 35 percent
Texture - silty clay loam, loam, clay loam, silt loam
Gravel content 10 to 35 percent
Cobble content 0 to 25 percent
Total rock fragment content - 10 to 45 percent

COMPETING SERIES: These are the Annum, Brownlee, Chirpchatter, Ebadlow, Felton, Fisherhill, Goldendale, Hellake, Lompico, Lorena, Meland, Mendian (T), Meystre, Quiden, Rehfield, Robbscreek, Stacker, Stardust, Updegraff and Van Horn series.
Annum soils are deep to a paralithic contact, have buried Bt horizons, and have 2Bk or 2BC horizons with a soil reaction of slightly to medium alkaline. Brownlee and Felton soils are deep to a paralithic contact. Chirpchatter, Ebadlow, Fisherhill, Hellake, Mendian (T), Meystre, Quiden, Rehfield, Stardust, and Van Horn soils are very deep. Goldendale soils have Bt horizons that extend to depths of 60 inches or more and less than 25 percent medium sand or coarser in the particle-size control section. Lompico, Lorena, Meland, Robbscreek, and Stacker soils are 20 to 40 inches deep. Updegraff soils are dry more than 60 consecutive days and have an O horizon and lack silty clay loam textures in the subsoil.

GEOGRAPHIC SETTING: These soils occur at elevations of 2,200 to 4,000 feet. Slopes are 0 to 65 percent. The soils formed in loess and residual material from quartzite, sandstone or intrusive igneous rock and are on hills and mountains. The mean January temperature is about 27 degrees F.; the mean July temperature is about 67 degrees F.; and the mean annual temperature is about 47 degrees F. The frost free period is 120 to 140 days and the average annual precipitation is 18 to 24 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Garfield, Larkin, Naff, Palouse, Speigle, Tekoa, Tilma, and Thatuna soils. Garfield soils have an ochric epipedon and are fine. Larkin, Naff, Palouse and Thatuna soils are fine-silty. Speigle soils are loamy-skeletal and have a cambic horizon. Tekoa soils are 20 to 40 inches deep to bedrock. Tilma soils are fine.

DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderately slow permeability.

USE AND VEGETATION: Native vegetation is Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, common snowberry, arrowleaf balsamroot, prairie junegrass, and some scattered ponderosa pine. Cultivated areas are used for production of small grains, peas, alfalfa and grass.

DISTRIBUTION AND EXTENT: Eastern Washington and northern Idaho. Schumacher soils are of moderate extent. MLRA 9.

MLRA OFFICE RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Whitman County, Washington, 1942.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon the zone from the surface to 19 inches (the Ap, A, and AB horizons)
Argillic horizon the zone from 19 to 43 inches (the Bt1, Bt2, and Bt3 horizons)
Lithic contact - at 43 inches
Particle-size control section the zone from 19 to 39 inches (the Bt1 and Bt2 horizons and the upper part of the Bt3 horizon)