LOCATION NEARL IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic Vertic Haplocryolls
TYPICAL PEDON: Nearl loam, supporting a subalpine fir/western meadowrue habitat type, woodland; on a rolling slope of 15 percent on a south aspect;about 6,915 feet elevation. (Colors are for air dry soil unless otherwise noted.)
Oi-0 to 2 inches; forest litter of needles and leaves; abrupt broken boundary.
A1--2 to 6 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and common medium and coarse roots; many very fine irregular pores; 5 percent pebbles, trace of cobbles and stones; slightly acid (pH 6.2); abrupt wavy boundary. (2 to 6 inches thick)
A2--6 to 12 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure parting to moderate fine subangular blocky; hard, friable, sticky and plastic; common very fine and fine and few medium and coarse roots; many very fine and few fine irregular pores; 5 percent pebbles, trace of cobbles and stones; slightly acid (pH 6.2); abrupt irregular boundary. (5 to 10 inches thick)
Bw1--12 to 23 inches; light yellowish brown (10YR 6/4) cobbly clay loam, yellowish brown (10YR 5/4) moist; moderate medium prismatic structure parting to strong fine subangular blocky; hard, firm, sticky and plastic; few very fine, fine, medium, and coarse roots; common very fine tubular pores; many distinct uncoated silt grains on faces of peds; 10 percent pebbles, 10 percent cobbles, 5 percent stones; slightly acid (pH 6.2); clear wavy boundary. (2 to 15 inches thick)
Bw2--23 to 41 inches; yellowish brown (10YR 5/4) clay, brown (10YR 4/3) moist; moderate coarse prismatic structure parting to moderate coarse subangular blocky; very hard, very firm, sticky and very plastic; few very fine roots; common very fine and few fine tubular pores; very few 1/16 inch wide vertical desication cracks; common fine distinct dark brown (7.5YR 3/2) soft masses of manganese accumulations in matrix, dark brown (7.5YR 3/2) moist; common fine distinct brownish yellow (10YR 6/6) soft masses of iron accumulations in matrix, yellowish brown (10YR 5/6) moist; few fine distinct very dark gray (N 3/) manganese concretions in matrix, very dark gray (N 3/) moist; many fine distinct light gray (2.5Y 7/2) clay depletions on faces of peds and lining fine pores, grayish brown (2.5Y 5/2) moist; few fine prominent gray (5Y 6/1) iron depletions lining fine pores, gray (5Y 5/1) moist; 10 percent pebbles, trace of cobbles and stones; slightly acid (pH 6.1), gradual wavy boundary. (15 to 25 inches thick)
Bss--41 to 60 inches; light yellowish brown (2.5Y 6/4) clay, light olive brown (2.5Y 5/4) moist; weak coarse subangular blocky structure; very hard, very firm, sticky and very plastic; few very fine roots; common very fine tubular pores; very few 1/8 to 1/4 inch wide vertical desication cracks; few distinct slickensides; common coarse distinct grayish brown (2.5Y 5/2) iron depletions in an irregular matrix, dark grayish brown (2.5Y 4/2) moist; few fine prominent dark brown (7.5YR 3/2) soft masses of manganese accumulations lining pores, dark brown (7.5YR 3/2) moist; few fine prominent brownish yellow (10YR 6/6) soft masses of iron adjacent to pores, yellowish brown (10YR 5/6) moist; few fine prominent very dark gray (N 3/) manganese concretions in matrix, very dark gray (N 3/) moist; common fine distinct light gray (10YR 7/2) clay depletions lining pores, grayish brown (10YR 5/2) moist; 10 percent pebbles, trace of cobbles and stones; slightly acid (pH 6.2).
TYPE LOCATION: Clark County, Idaho; about 32 miles northeast of Dubois Idaho; about 2,200 feet west and 1,400 feet north of the southeast corner of section 32, T. 14 N., R. 40 E.; Latitude - 44 degrees, 29 minutes, 03 seconds North; Longitude - 111 degrees, 46 minutes, 05 seconds West.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 10 to 16 inches
Clay content in the particle-size control section, weighted average - 35 to 45 percent
Rock fragments in the particle-size control section, weighted average - 0 to 35 percent
Mean annual soil temperature - 35 to 40 degrees F.
Mean summer soil temperature - 40 to 45 degrees F.
Moisture control section - between 4 and 12 inches; dry throughout the moisture control section for less than 30 consecutive days
in the four months following the summer solstice
These soils have a perched water table at a depth of 1.0 to 2.5 feet from June through July. It occurs during and shortly after peak
snowmelt periods and after heavy rains of several days duration.
A horizon
Value - 3 or 4 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Reaction - slightly acid or neutral
Bw1 horizon
Hue - 7.5YR or 10YR
Value, matrix - 5 to 7 dry, 3 to 5 moist
Chroma, matrix - 2 to 4 dry or moist
Texture, less than 2 mm fraction - clay loam or silty clay loam
Clay content - 27 to 40 percent
Rock fragment content - 0 to 35 percent
Pebbles - 0 to 25 percent
Cobbles - 0 to 30 percent
Stones - 0 to 5 percent
Reaction - slightly acid or neutral
Bw2 and Bss horizons
Hue - 5YR to 5Y
Texture, less than 2 mm fraction - silty clay, silty clay loam, or clay
Clay content - 35 to 50 percent
Rock fragment content - 0 to 15 percent
Pebbles - 0 to 10 percent
Cobbles - 0 to 10 percent
Stones - 0 to 5 percent
Reaction - moderately acid to slightly alkaline
Cracks - very few or few subsurface initiated reversible cracks
COMPETING SERIES: These are the Elkhead and Leaps series. The Elkhead soils have horizons of secondary carbonate accumulation. The Leaps soils have an ustic moisture regime and are well drained.
GEOGRAPHIC SETTING: The Nearl soils occur on the complex slopes of a slump-earthflow topography in mountain basins and in saddles. Slopes range from 4 to 20 percent. The soil formed in a cap of local alluvium derived from mixed sources over residuum from fine textured lacustrine sediments. Elevations range from 5,700 to 8,000 feet. The average annual precipitation is 24 to 35 inches. The average annual air temperature is 33 to 38 degrees F. The frost free season is 15 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fitzwil, Rhylow and Koffgo series. All three soils occur intermixed with the Nearl soil on ridges and knolls that are associated with relic volcanic caps. They also occur on adjacent mountain sideslopes. Each is well drained and has greater than 35 percent rock fragments in the particle-size control section. Fitzwil soils have argillic horizons that average 18 to 27 percent clay beginning at depths of 24 to 40 inches. Rhylow and Koffgo soils average less than 18 percent clay throughout the profile.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to moderate runoff; slow permeability.
USE AND VEGETATION: Nearl soils are used for wildlife habitat, recreation and livestock grazing. These soils commonly support a subalpine fir/western meadowrue plant association.
DISTRIBUTION AND EXTENT: Southeastern Idaho and southwestern Montana. The soil is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Targhee National Forest, Fremont County, Idaho, 1997.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the mineral soil surface to 10 inches (the A1 and A2 horizons).
Cambic horizon - the zone from 10 to 60 inches (the Bw1, Bw2, and Bss horizons).
Particle-size control section - the zone from 10 to 40 inches (the Bw1, Bw2, and part of the Bss horizons).
Distinct or prominent redox concentrations - the zone from 21 to 60 inches (the Bw2 and Bss horizons).
Vertic feature - the zone from 21 to 60 inches (Bw2 and Bss horizons)
Moisture regime - udic