LOCATION TOMODO ID
Established Series
Rev. GAH-BDG-EMM
07/2013
TOMODO SERIES
The Tomodo series consists of very deep, well drained soils formed in loamy colluvium with a thick volcanic ash mantle. They are on mountain slopes, ridges and structural benches. Saturated hydraulic conductivity is moderately low and slopes range from 15 to 40 percent. The average annual precipitation is about 40 inches and the average annual temperature is about 43 degrees F.
TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic, frigid Alfic Udivitrands
TYPICAL PEDON: Tomodo ashy silt loam, forested on a 35 percent slope at 3,250 feet elevation. Aspect is southeast. (Colors are for dry soil unless otherwise noted.
Oi--0 to 2 inches; slightly decomposed needles, twigs and leaves. (0 to 2 inches thick)
A--2 to 3 inches; brown (10YR 5/3) ashy silt loam, dark yellowish brown (10YR 3/4) moist; weak coarse granular structure; soft, very friable, nonsticky and non-plastic; common very fine and fine roots; many very fine irregular pores; neutral (pH 6.8); abrupt wavy boundary. (1 to 5 inches thick)
Bw1--3 to 11 inches; yellowish brown (10YR 5/4) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure parting to moderate coarse granular; soft, very friable, nonsticky and slightly plastic; common very fine and fine, and few medium roots; common very fine irregular pores; neutral (pH 6.8); diffuse smooth boundary.
Bw2--11 to 20 inches; brownish yellow (10YR 6/6) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure parting to moderate coarse granular; soft, very friable, nonsticky and slightly plastic; common very fine, fine and medium roots; common very fine irregular pores; slightly acid (pH 6.2); abrupt wavy boundary. (Bw horizons 9 to 17 inches thick)
2E--20 to 23 inches; very pale brown (10YR 7/3) loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots on ped faces and few very fine roots throughout; common very fine tubular pores; 10 percent fine mica flakes; moderately acid (pH 6.0); clear wavy boundary. (0 to 10 inches thick)
2E/B--23 to 30 inches; E - 85 percent very pale brown (10YR 7/3) loam, yellowish brown (10YR 5/4) moist; B - 15 percent yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots along ped faces and few very fine roots throughout; common very fine tubular pores; 10 percent fine mica flakes; moderately acid (pH 6.0); clear wavy boundary. (0 to 18 inches thick)
2Bt/E--30 to 42 inches; B - 60 percent yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; E - 40 percent very pale brown (10YR 7/3) loam, yellowish brown (10YR 5/4) moist; weak very coarse prismatic structure parting to moderate coarse subangular blocky; extremely hard, firm, slightly sticky and moderately plastic; few very fine, fine and medium roots along ped faces; many very fine tubular pores; common faint clay films on faces of peds and common distinct clay films in pores; 10 percent fine mica flakes; strongly acid (pH 5.2); gradual wavy boundary.
2Btx/E--42 to 51 inches; B - 75 percent yellowish brown (10YR 5/4) clay loam, dark yellowish brown (10YR 4/4) moist; E - 25 percent very pale brown (10YR 7/3) loam, brown (10YR 5/3) moist; weak very coarse prismatic structure parting to moderate medium and coarse angular blocky; extremely hard, firm, moderately sticky and moderately plastic; few fine roots along ped faces; many very fine tubular pores; common distinct brown (7.5YR 4/4) moist clay films in pores and on faces of peds; 25 percent of horizon is brittle moist; 10 percent fine mica flakes; strongly acid (pH 5.2); gradual wavy boundary. (2B/E horizons 0 to 21 inches thick)
2Btx1--51 to 62 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 3/4) moist; weak very coarse prismatic structure parting to moderate medium and coarse angular blocky; extremely hard, firm, moderately sticky and moderately plastic; few fine roots along ped faces; many very fine tubular pores; many distinct brown (7.5YR 4/4) moist clay films in pores and on faces of peds; many prominent light gray (10YR 7/2) silt grains in pores and on faces of peds; 40 percent of horizon is brittle when moist; 10 percent fine mica flakes; strongly acid (pH 5.2); gradual smooth boundary. (0 to 12 inches thick)
2Btx2--62 to 66 inches; light yellowish brown (10YR 6/4) clay loam, dark yellowish brown (10YR 3/4) moist; strong medium prismatic structure; extremely hard, very firm, moderately sticky and moderately plastic; few very fine roots along faces of peds; few very fine tubular pores; many prominent brown (7.5YR 4/4) moist clay films on faces of peds; 50 percent of horizon is brittle when moist; 5 percent fine mica flakes; strongly acid (pH 5.4).
TYPE LOCATION: Latah County, Idaho, about 5 miles north and 3 miles east of Cavendish, Idaho; about 1,700 feet south and 1,800 feet west of the northeast corner of section 18, T. 38 N., R. 1 E.; Latitude - 46 degrees, 38 minutes, 19 seconds North; Longitude - 116 degrees, 22 minutes, 41 seconds West. USGS Park Quadrangle.
RANGE IN CHARACTERISTICS:
Depth to fragic characteristics - 20 to 50 inches
Depth to argillic horizon - 15 to 32 inches
Average annual soil temperature - 39 to 45 degrees F. (Frigid temperature regime)
Soil moisture regime - usually moist year round and not dry for 30 consecutive days during June to October. (Udic soil moisture regime)
Thickness of volcanic ash mantle - 14 to 20 inches
Volcanic glass content - 15 to 50 percent
Acid-oxalate extractable Al + 1/2 Fe - 1.3 to 2.7 percent
15 bar water retention - 8 to 12 percent
Phosphate retention - 55 to 90 percent
A horizon
Hue - 7.5YR or 10YR dry
Value - 2 to 5 dry, 2.5 or 3 moist
Chroma - 2 to 4 dry or moist
Textures - ashy silt loam or ashy loam
Clay content - 8 to 10 percent
Reaction - 5.8 to 6.7
Moist bulk density - 0.65 to 0.85 g/cc
Bw horizons
Hue - 7.5YR or 10YR dry
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 4 to 6 dry
Texture - ashy silt loam or ashy loam
Clay content - 8 to 10 percent
Rock fragments - 0 to 1 percent gravel
Reaction - 5.4 to 7.3
Moist bulk density - 0.65 to 0.90 g/cc
2E and 2E/B horizons
E part
Hue - 7.5YR or 10YR dry or moist
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry
Textures - silt loam, loam or very fine sandy loam
Clay content - 12 to 20 percent
B part
Hue - 7.5YR or 10YR dry or moist
Value - 5 or 6 dry, 3 or 4 moist
Textures - silt loam or loam
Clay content - 20 to 24 percent
Rock fragments - 0 to 5 percent gravel
Reaction - 5.2 to 6.0
2Bt/E or 2Btx/E horizons
B part
Hue - 7.5YR or 10YR dry or moist
Value - 5 or 6 dry, 3 to 5 moist
Chroma - 3 to 6 dry or moist
Textures - silt loam, loam or clay loam
Clay content - 20 to 27 percent
E part
Hue - 7.5YR or 10YR dry or moist
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 to 6 dry or moist
Textures - silt loam, loam or very fine sandy loam
Clay content - 15 to 20 percent
Rock fragments - 0 to 5 percent gravel
Reaction - 5.1 to 6.1
2Btx1 horizon
Hue - 10YR to 5YR dry or moist
Value - 5 to 7 dry, 3 to 6 moist
Chroma - 4 to 6 dry, 3 to 6 moist
Texture - clay loam or loam
Clay content - 12 to 35 percent
Rock fragments - 0 to 5 percent gravel
Mica content - 1 to 40 percent
Reaction - 5.1 to 6.1
2Btx2 horizon
Hue - 10YR to 5YR dry or moist
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 4 to 6 dry or moist
Texture - clay loam or loam
Clay content - 18 to 35 percent
Rock fragments - 0 to 15 percent gravel, 0 to 5 percent cobbles, 0 to 20 total rock fragments
Mica content - 1 to 70 percent
Fragic characteristics - 25 to 50 percent of horizon is brittle when moist
Reaction - 4.9 to 5.7
COMPETING SERIES:
Dowper soils: do not have fragic properties
Jacot soils: do not have fragic properties
Mackatie soils: are deep to a paralithic contact of andesite; do not have fragic properties
Secunda soils: do not have fragic properties
Tamara soils: have 2Btb horizons with 5 to 30 percent fragments of basalt; do not have fragic properties
Turpentine soils: have a lithic contact at 43 to 78 inches (109 to 198 cm); do not have fragic properties
GEOGRAPHIC SETTING: Tomodo soils are on mountain slopes, ridges and structural benches at elevations of 1,700 to 4,200 feet (518 to 1280 meters) with slopes of 15 to 40 percent. These soils formed in loamy colluvium with a thick mantle of volcanic ash. The average annual temperature is 38 to 46 degrees F. and the average annual precipitation is 30 to 50 inches (762 to 1270 mm). The frost free season is 50 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Lado,
Norwidge and
Threebear soils. The Lado soils are on hills and do not have fragic characteristics. Norwidge soils are on hills and have silt loam and silty clay loam textures in the argillic horizon. Threebear soils are on hills and are moderately deep to a fragipan.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff and moderately low saturated hydraulic conductivity.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat and watershed. Potential natural vegetation is western redcedar, grand fir, Douglas-fir and western larch with an understory of queencup beadlily, starry false Solomons-seal, longtube twin flower, bunchberry dogwood, goldthread, darkwoods violet, common snowberry and Columbia brome.
DISTRIBUTION AND EXTENT: North central Idaho; Tomodo soils are not extensive. MLRA 43A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Clearwater County, Idaho, 2003.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric horizon - The zone from 0 to 3 inches. (Oi and A horizons)
Volcanic ash mantle - The zone from 2 to 20 inches. (A, Bw1 and Bw2 horizons)
Cambic horizon - The zone from 3 to 20 inches. (Bw1 and Bw2 horizons)
Argillic horizon - The zone from 30 to 66 inches. (2Bt/E, 2Btx/E, 2Btx1 and 2Btx2 horizons)
Particle size control section - The zone from 2 to 42 inches. (A, Bw1, Bw2, 2E, 2E/B, 2Bt/E horizons)
The ranges of values listed under the Range in Characteristics for the soil properties - Bulk density, Volcanic glass content, Acid-oxalate Al +1/2 Fe, Phosphate retention and 15 bar water retention are estimates only.
National Cooperative Soil Survey
U.S.A.