LOCATION TAMMANY IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Calcic Haploxerolls
TYPICAL PEDON: Tammany silt loam -- on an 38 percent west-facing slope at 1,100 feet elevation. When described on September 12, 1989 the soil was moist to 29 inches and dry below. (Colors are for dry soil unless otherwise stated).
A1-- 0 to 4 inches; brown (10YR 4/3) silt loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and plastic; many fine and very fine roots; many fine and very fine tubular pores; 10 percent gravel; neutral (pH 7.2); clear smooth boundary.
A2-- 4 to 10 inches; brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; many fine and very fine roots; many fine and very fine tubular pores; 30 percent gravel, 10 percent cobbles; neutral (pH 7.2); clear wavy boundary. (Combined thickness of the A horizons is 8 to 14 inches)
Bw-- 10 to 17 inches; yellowish brown (10YR 5/4) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common fine and very fine roots; common very fine tubular pores; 40 percent gravel, 15 percent cobbles; neutral (pH 7.2); clear wavy boundary. (4 to 18 inches thick)
Bk-- 17 to 29 inches; pale brown (10YR 6/3) extremely gravelly coarse sandy loam, yellowish brown (10YR 5/4) moist; weak coarse subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine and very fine roots; few very fine tubular pores; 45 percent gravel, 25 percent cobbles; strongly effervescent (10 percent calcium carbonate equivalent); lime disseminated and segregated as coatings on undersides of coarse fragments; moderately alkaline (pH 8.2); clear wavy boundary. (6 to 16 inches thick)
2C-- 29 to 60 inches; light gray (10YR 7/2) extremely gravelly coarse sand, light brownish gray (10YR 6/2) moist; single grain; loose; many fine irregular pores; 50 percent gravel, 30 percent cobbles; slightly effervescent; lime disseminated; moderately alkaline (pH 8.0).
TYPE LOCATION: Nez Perce County, Idaho; about 1 mile north of Lewiston, about 600 feet south and 1,100 feet west of the northeast corner, section 29, T. 36 N., R. 5 W. Latitude - 46 degrees, 26 minutes, 25 seconds north; Longitude - 116 degrees, 59 minutes, 03 seconds west. USGS quadrangle - Lewiston Orchards North.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 8 to 14 inches Depth to secondary carbonates - 15 to 30 inches Depth to 2C horizon - 25 to 40 inches Average annual soil temperature - 55 to 57 degrees F
Particle size control section (weighted averages) Clay content - 8 to 16 percent Coarse fragment content - 50 to 75 percent
A horizon Value - 4 or 5 dry Chroma - 2 or 3, dry or moist Reaction - neutral or mildly alkaline
Bw horizon Chroma - 3 or 4, dry or moist Textures - GRV-L, GRV-SL Coarse fragment content - 35 to 60 percent Gravel content - 25 to 40 percent Cobble content - 10 to 20 percent Clay content - 14 to 22 percent Reaction - neutral or mildly alkaline
Bk horizon Value - 5 or 6 dry, 3 through 5 moist Chroma - 3 or 4, dry or moist Textures - GRX-COSL, GRV-L, CBX-SL, CBX-L Coarse fragment content - 50 to 85 percent Clay content - 8 to 16 percent Calcium carbonate equivalent - 5 to 15 percent
2C horizon Value - 7 or 8 dry, 6 or 7 moist Coarse fragment content - 60 to 90 percent
COMPETING SERIES: These are the Alpowa, Bonnet, Copperton, Hupp, Lakewin, Middle, and Stricker series. The Alpowa, Hupp, Middle, and Stricker soils do not have a sand and gravel substratum within 40 inches. Bonnet soils do not have a cambic horizon. Copperton, Lakewin, and Stricker soils have average annual soil temperatures less than 54 degrees F. Copperton soils have weakly or moderately cemented Bk horizons. Lakewin soils have 15 to 20 percent calcium carbonate equivalent in the Bk horizon.
GEOGRAPHIC SETTING: Tammany soils are on erosional slopes of dissected terraces. Slopes range from 20 to 65 percent. These soils formed in re-worked loamy alluvium from mixed sources over gravelly alluvium from granitic rocks. Elevations are 750 to 1,200 feet. The average annual temperature ranges from 51 to 53 degrees F and the average annual precipitation is 12 to 15 inches. The average frost-free period is from 160 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chard and Pleasant View series. Chard soils lack coarse fragments and are on north- and east-facing slopes. Pleasant View soils are cumulic and are on lower terraces.
DRAINAGE AND PERMEABILITY: Well drained; rapid or very rapid runoff; moderate permeability in the upper part and very rapid permeability in the substratum.
USE AND VEGETATION: These soils are used for cropland and rangeland. Native vegetation is mainly bluebunch wheatgrass, Sandberg bluegrass, silky lupine, and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: This soil is of small extent in north central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Nez Perce County, Idaho 1995.
REMARKS: This revision changes the classification from coarse-loamy to loamy-skeletal and the name from Tammany Creek to Tammany.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 10 inches (A1 and A2 horizons).
Cambic horizon - The zone from 10 to 17 inches (Bw horizon).
Calcic horizon - the zone from 17 to 29 inches (Bk horizon).
Particle-size control section - The zone from 10 to 40 inches (Bw, Bk, and part of the 2C horizons).