LOCATION SLICKPOO IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Calcic Pachic Argixerolls
TYPICAL PEDON: Slickpoo silt loam -- on a northwest-facing slope of 11 percent at 2,840 feet elevation in a cultivated field. When described on July 9, 1985, the soil was dry to 4 inches and moist below. (Colors are for dry soil unless otherwise stated).
Ap--0 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 and slightly plastic; many very fine roots; common very fine and fine tubular pores; slightly acid (pH 6.1); clear smooth boundary. (10 to 14 inches thick)
BA--12 to 17 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate medium angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; common very fine and fine tubular pores; very few thin clay films on faces of peds; neutral (pH 6.4); gradual wavy boundary. (3 to 6 inches thick)
Bt1--17 to 22 inches; yellowish brown (10YR 5/4) silty clay loam, dark brown (10YR 3/3) moist; weak medium angular blocky structure; hard, friable, sticky and plastic; common very fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds; neutral (pH 7.2); clear wavy boundary. (4 to 10 inches thick)
2Bt2--22 to 32 inches; yellowish brown (10YR 5/4) cobbly silty clay loam, dark yellowish brown (10YR 3/4) moist; weak medium angular blocky structure; hard, firm, sticky and plastic; common very fine roots; many very fine and fine tubular pores; many prominent clay films on faces of peds; 10 percent gravel and 15 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (8 to 12 inches thick)
2Btk--32 to 37 inches; yellowish brown (10YR 5/4) cobbly silty clay loam, brown (10YR 4/3) moist; weak medium angular roots; many very fine and fine tubular pores; few thin clay films in pores; slightly effervescent; lime segregated in few fine filaments; 10 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 8 inches thick)
2Bk--37 to 45 inches; light gray (10YR 7/2) very cobbly silt loam, brown (10YR 5/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine tubular pores; violently effervescent; lime disseminated; 20 percent gravel and 40 percent cobbles; moderately alkaline (pH 8.4); abrupt wavy boundary. (7 to 10 inches thick)
3R--45 inches; basalt.
TYPE LOCATION: Nez Perce County, Idaho; about 1 mile northwest of Waha, about 1,900 feet south and 20 feet west of the northeast corner of section 6, T. 33 N., R. 4 W. Latitude - 46 degrees, 14 minutes north; Longitude - 116 degrees, 52 minutes, 30 seconds west. USGS quadrangle - Captain John Rapids.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 20 to 28 inches.
Depth to secondary carbonates - 28 to 35 inches.
Depth to bedrock - 40 to 55 inches.
Average annual soil temperature - 51 to 54 degrees F.
Ap horizon
Value - 3 or 4 dry
Chroma - 1 or 2, dry or moist
Bt horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 3 or 4, dry or moist
Textures - SIL, SICL
Clay content - 22 to 32 percent
Gravel content - 0 to 10 percent
Reaction - neutral or slightly alkaline
2Bt and 2Btk horizons (2Btk horizon is not present in all pedons) Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4, dry or moist
Clay content - 28 to 36 percent
Rock fragment content - 15 to 35 percent
Reaction - neutral or slightly alkaline
2Bk horizon
Value - 6 through 8 dry, 5 or 6 moist
Chroma - 2 through 4, dry or moist
Textures - CBV-SIL, CBV-L
Clay content - 20 to 27 percent
Rock fragment content - 35 to 60 percent
COMPETING SERIES: These are the Crookston, Newell, Peola, and Roystone series. Crookston soils are 20 to 28 inches to secondary carbonates and average annual soil temperature less than 52 degrees F. Newell and Roystone soils are not cobbly in the lower part of the argillic horizon and lack a lithologic discontinuities in their argillic horizons. Peola soils contain durinodes and are moderately deep to a lithic contact.
GEOGRAPHIC SETTING: Slickpoo soils are on south and west facing sideslopes on hills on basalt plateaus. Slopes range 5 to 25 percent. These soils formed in loess and material weathered from basalt at elevations of 1,600 and 2,900 feet. The average annual temperature ranges from 49 to 52 degrees F., with an average annual precipitation of 15 to 18 inches. The average frost-free period is from 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Broadax and Kettenbach series. Broadax soils are on plateau summits and lack coarse fragments. Kettenbach soils are on canyon slopes and are loamy-skeletal and moderately deep.
DRAINAGE AND PERMEABILITY: Well drained; moderate to rapid runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for cropland, mainly winter wheat. Native vegetation is mainly Idaho fescue, bluebunch wheatgrass, and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: This soil is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Nez Perce County, Idaho, 1995.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 22 inches (the Ap, BA, and Bt1 horizons).
Argillic horizon - the zone from 17 to 37 inches (the Bt1, 2Bt2, and 2Btk horizon).
Calcic horizon - the zone from 37 to 45 inches (the 2Bk horizon).
Particle-size control section - the zone from 17 to 37 inches (the Bt1, 2Bt2, and 2Btk horizons).