LOCATION HEDOES MT
Established Series
Rev. NRS-CNG-EMM
12/2012
HEDOES SERIES
The Hedoes series consists of very deep, well drained soils that formed in colluvium and alluvium from igneous rocks. These soils are on alluvial fans, stream terraces, hills, and mountains. Slopes are 0 to 60 percent. Mean annual precipitation is about 16 inches, and mean annual temperature is about 43 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Pachic Haplustolls
TYPICAL PEDON: Hedoes loam, pastureland (colors are for dry soil unless otherwise noted).
Ap--0 to 4 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and nonplastic; many medium and fine roots; neutral (pH 6.6); clear boundary.
A2--4 to 9 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and nonplastic; common fine roots; common fine and very fine pores; 5 percent gravel; slightly alkaline (pH 7.4); clear boundary. (combined thickness of A horizons is 8 to 16 inches thick)
Bw--9 to 17 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, very friable, nonsticky and nonplastic; common fine roots; common fine pores; 5 percent gravel; slightly alkaline (pH 7.6); clear wavy boundary. (8 to 26 inches thick)
Bk1--17 to 34 inches; grayish brown (10YR 5/2) coarse sandy loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine roots; 10 percent gravel; strongly effervescent; common fine masses and seams of lime; moderately alkaline (pH 8.4); gradual irregular boundary. (6 to 24 inches thick)
2Bk2--34 to 60 inches; grayish brown (10YR 5/2) very gravelly coarse sandy loam, dark grayish brown (10YR 4/2) moist; single grain; soft, very friable, nonsticky and nonplastic; 45 percent gravel, and 5 percent cobbles; disseminated lime; strongly effervescent, continuous thin lime casts on underside of fragments; moderately alkaline (pH 8.4).
TYPE LOCATION: Blaine County, Montana; 100 feet east and 2,640 feet north of the SW corner of sec. 3, T. 25 N., R. 19 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 8 to 24 inches.
Mollic epipedon thickness - 16 to 35 inches.
Depth to Bk horizon - 16 to 35 inches.
A horizons
Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: loam or sandy loam
Clay content: 5 to 18 percent
Rock fragments: 0 to 25 percent--0 to 5 percent cobbles, 0 to 2 percent gravel
Reaction: pH 6.6 to 7.3
Bw horizon
Hue: 7.5YR, 10YR, or 2.5Y
Value: 4 or 5 dry; 2, 3, or 4 moist
Chroma: 2 or 3, dry or moist
Texture: loam or sandy loam
Clay content: 5 to 18 percent
Rock fragments: 0 to 20 percent--0 to 10 percent cobbles, 0 to 10 percent gravel
Reaction: pH 6.6 to 8.4
Some pedons have a cambic horizon.
Bk1 horizon
Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, coarse sandy loam, or loamy sand
Clay content: 0 to 12 percent
Rock fragments: 5 to 35 percent
Calcium carbonate equivalent: 5 to 10 percent
Reaction: pH 6.6 to 8.4
2Bk2 horizon
Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, coarse sandy loam, or loamy sand
Clay content: 0 to 10 percent
Rock fragments: 30 to 60 percent
Reaction: pH 7.4 to 8.4
Some pedons do not have 2Bk2 horizon.
COMPETING SERIES:
Breece (CO) - do not have accumulations of secondary carbonates.
Breeton (MT) - do not have accumulations of secondary carbonates.
Chrishall (NM) - have a cambic horizon, do not have horizons of secondary carbonate accumulation, and receive more than 20 inches of precipitation.
Coberly (CO) - has sandstone bedrock at depths of 20 to 40 inches.
Dotsero (CO) - have 15 to 30 percent basalt gravel in the control section and no discontinuity that is loamy-skeletal above 40 inches.
Klizhin (NM) - do not have horizons of secondary carbonate accumulations and have buried argillic horizons below a depth of 40 inches.
Parshall (ND) - do not have a discontinuity with more than 30 percent above a depth of 40 inches and are mainly deeper than 24 inches.
Ruso (ND) - have sandy-skeletal materials above a depth of 40 inches.
Tuntsa (NM) - do not have horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING:
Landform - alluvial fans, stream terraces, hills, and mountains.
Elevation - 3,000 to 6,000 feet.
Slope - 0 to 60 percent.
Parent material - alluvium and colluvium from igneous rocks.
Climate - long, cold winters; moist springs, and warm summers.
Mean annual precipitation - 14 to 19 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability above the 2Bk2 horizon and moderately rapid in the 2Bk2 horizon.
USE AND VEGETATION: Hedoes soils are used mainly for range; some areas are used for dryland farming and irrigated hay. Potential native vegetation is rough fescue, bluebunch wheatgrass, prairie junegrass, porcupinegrass, green needlegrass, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Hedoes soils are of moderate extent in and/or adjacent to the mountains in central Montana. MLRAs 43B, 44B, 46, and 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Blaine County, Montana, 1976.
REMARKS: Soil interpretations record: MT0277, MT1083.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to 17 inches (A1, A2, Bw horizons);
Secondary carbonate accumulations from 17 to 60 inches (Bk1, 2Bk2 horizons);
Particle-size control section from 10 to 40 inches (Bw, Bk, 2Bk2 horizons).
Hedoes soils have a frigid temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.