LOCATION BONNER ID+MT WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, aniso, glassy over isotic, frigid Typic Vitrixerands
TYPICAL PEDON: Bonner gravelly ashy silt loam, forest; on a 2 percent slope at 2,300 feet elevation. When described on September 9, 1968, the soil was slightly moist. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 0.3 inches; fresh coniferous needles and twigs.
Oe--0.3 to 1.1 inches; partially decayed needles and twigs.
Oa--1.1 to 1.3 inches; well decayed organic matter mixed with light gray Mt. St. Helens volcanic ash.
A--1.3 to 5 inches; pale brown (10YR 6/3) gravelly ashy silt loam, dark brown (10YR 3/3) moist; weak very fine granular structure; soft, very friable, nonsticky and slightly plastic; many fine and medium roots; many fine irregular pores; 15 percent pebbles; slightly acid (pH 6.3); abrupt smooth boundary. (3 to 6 inches thick)
Bw--5 to 21 inches; pale brown (10YR 6/3) gravelly ashy silt loam, brown (10YR 4/3) moist; weak very fine granular structure; soft, very friable, nonsticky and slightly plastic; many fine and medium roots; many very fine irregular pores; 15 percent pebbles; slightly acid (pH 6.3); abrupt smooth boundary. (11 to 18 inches thick)
2BC--21 to 29 inches; very pale brown (10YR 7/3) gravelly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and slightly plastic; many fine roots; many fine tubular pores; 25 percent pebbles and cobbles; slightly acid (pH 6.2); gradual wavy boundary. (7 to 10 inches thick)
3C1--29 to 39 inches; very pale brown (10YR 7/3) very gravelly loamy sand, brown (10YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many fine roots; many fine and few coarse tubular pores; 40 percent pebbles and cobbles; slightly acid (pH 6.1); gradual wavy boundary. (8 to 15 inches thick)
3C2--39 to 60 inches; very pale brown (10YR 7/3) very gravelly loamy sand, brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; few fine roots; many fine and medium irregular pores; 60 percent pebbles and cobbles; neutral (pH 6.7).
TYPE LOCATION: Bonner County, Idaho; about 1.5 miles southeast of Oldtown, Idaho; approximately 100 feet north and 2,100 feet east of the southwest corner, sec. 30, T. 56 N., R. 5 W. Latitude - 48 degrees, 10 minutes, 00 seconds North; Longitude - 116 degrees, 00 minutes, 44 seconds West; USGS - Newport 15 minute quadrangle.
RANGE IN CHARACTERISTICS:
Soil moisture control section - dry 45 to 60 days July to September, moist October through June Average annual soil temperature - 43 to 47 degrees F. Average summer soil temperature - 50 to 55 degrees F. with an O horizon Solum thickness - 24 to 36 inches Reaction - moderately acid to neutral throughout
Volcanic ash mantle - 14 to 26 inches thick Volcanic glass content in the 0.02 to 2.0 mm fraction - 40 to 70 percent Acid-oxalate extractable Al + 1/2 Fe - 1 to 3 percent Phosphate retention - 55 to 90 percent 15-bar water content an air dried samples - 7 to 12 percent
A horizon Value - 5 through 7 dry, 3 through 5 moist Chroma - 1 through 3 dry or moist Texture - A-SIL, GR-A-SIL, CB-A-SIL, GR-A-L, A-L Bulk density - 0.70 to 0.95 g/cc Rock fragments - 0 to 20 percent
Bw horizon Hue - 10YR or 7.5YR Value - 5 through 7 dry, 3 or 4 moist Chroma - 3 or 4 dry or moist Texture - GR-A-SIL, GR-A-L, A-SIL, A-L Bulk density - 0.70 to 0.95 g/cc Rock fragments - 0 to 30 percent
2BC horizon Value - 6 or 7 dry, 4 or 5 moist Chroma - 3 or 4 dry or moist Texture - GR-SL, GR-L Rock fragments - 15 to 35 percent
3C horizon Hue - 10YR or 2.5Y Value - 6 or 7 dry, 4 or 5 moist Chroma - 2 through 4 dry or moist Texture - GRV-LS, GRV-S, GRV-COS, GRX-LS, GRX-S, GRX-COS Rock fragments - 35 to 85 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Bonner soils are on terraces and terrace escarpments. Elevations range from 2,000 to 3,200 feet. Slope ranges from 0 to 15 percent on the terraces and 15 to 65 percent on the escarpments. These soils formed in glacial outwash material derived dominantly from granite, gneiss, and schist. They have a mantle of volcanic ash and loess. The average annual air temperature ranges from 42 to 47 degrees F. and the average annual precipitation ranges from 25 to 35 inches. Frost-free period ranges from 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dufort, Hoodoo, Kaniksu, Kootenai, Pend Oreille, Rathdrum, and Treble soils. Dufort, Pend Oreille, and Treble soils are on foothills and lack sandy-skeletal textures within a depth of 40 inches. Hoodoo soils are on valley bottoms and flood plains and are poorly drained. Kaniksu soils are on terraces and have less than 35 percent coarse fragments within a depth of 40 inches. Kootenai soils are on terraces and have a thicker A horizon and contain less volcanic ash in the surface layers. Rathdrum soils are in swales on terraces and contain high amounts of volcanic ash and have less than 35 percent rock fragments throughout the profile.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow on the terraces and ranges from medium to rapid on the escarpments. Permeability is moderate in the solum and rapid or very rapid in the underlying material.
USE AND VEGETATION: These soils are used for timber production, grazing, homesites, cropland, hay and pasture, recreation, and wildlife habitat. Natural vegetation is mainly grand fir, Douglas-fir, ponderosa pine, lodgepole pine, and western larch, with an understory of pine reedgrass, myrtle pachystima, baldhip rose, common snowberry, longtube twinflower, American trailplant, piper anemone, goldthread, sedge, and common princes pine.
DISTRIBUTION AND EXTENT: Northern Idaho, northeastern Washington, and northwestern Montana. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bonner County, Idaho, 1935.
REMARKS: The revision of 1/92 changed the classification from Coarse-loamy over sandy or sandy-skeletal, mixed, frigid Andic Xerochrepts to Ashy over sandy or sandy-skeletal, mixed, frigid Typic Vitrixerands based on the Andisol criteria. The revision of March 1996 changed the classification from Ashy over sandy or sandy-skeletal, mixed, frigid Typic Vitrixerands based on the Andisol criteria to Ashy over loamy-skeletal, aniso, glassy over isotic, frigid Typic Vitrixerands based on the revised family criteria.
Diagnostic horizons and features recognized in the pedon are:
Ochric epipedon - From 1.3 to 5 inches (A horizon)
Cambic horizon - From 5 to 29 inches (Bw and BC horizons)
Particle-size control section - From 0 to 40 inches (A, Bw, 2BC, 3C1, and part of the 3C2 horizons)
ADDITIONAL DATA: National Soil Survey Laboratory Pedon Numbers -
S68ID-017-002, S78ID-017-002, S78ID-017-008, S86ID-017-002, S68WA-065-001, S68WA-065-002.