LOCATION ROACHGULCH WY
Tentative Series
IRD. DEW/JCK
02/2017
ROACHGULCH SERIES
The Roachgulch series consist of very deep, moderately well drained soils that formed in alluvium. These soils are on alluvial fans and stream terraces. Slopes are 0 to 8 percent. Mean annual precipitation is about 191 mm, and mean annual air temperature is about 7 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquic Haplargids
TYPICAL PEDON: Roachgulch sandy clay loam, 1 percent slope in cropland at an elevation of 1,457 meters (colors are for dry soil unless otherwise noted).
Ap--0 to 20 cm; yellowish brown (10YR 5/4) sandy clay loam, brown (10YR 4/3) moist; weak medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots throughout; very slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (18 to 35 cm thick)
Bt1--20 to 42 cm; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots throughout, common very fine tubular pores; 10 percent faint clay films on all faces of peds; very slightly effervescent; slightly alkaline (pH 7.7); clear smooth boundary.
Bt2--42 to 60 cm; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots throughout, many very fine tubular pores; 5 percent faint clay films on faces of peds; 5 percent fine 10YR 3/1 manganese masses, 5 percent fine 7.5YR 5/6 oxidized iron masses, 2 percent fine 10YR 6/2 iron depletions; very slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (combined thickness of Bt horizons is 18 to 50 cm)
C--60 to 88 cm; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots throughout; 10 percent fine 7.5YR 5/6 oxidized iron masses, 5 percent fine 10YR 6/2 iron depletions; very slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (20 to 70 cm thick)
Btb--88 to 110 cm; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 5 percent faint clay bridging between sand grains; 5 percent fine 10YR 3/1 manganese masses, 3 percent fine 7.5YR 5/6 oxidized iron masses, 10 percent fine 2.5Y 6/1 iron depletions; very slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 40 cm thick)
C'--110 to 200 cm; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; single grain; loose, nonsticky and nonplastic; 2 percent fine 7.5YR 5/6 oxidized iron masses, 5 percent fine 2.5Y 6/1 iron depletions; slightly alkaline (pH 7.4).
TYPE LOCATION: Park county Wyoming; 743 meters south and 184 meters east of the northwest corner of section 24, T. 51N., R. 98W.; YU Bench NE USGS quadrangle; latitude 44 degrees 22 minutes 44.69 seconds N. and longitude 108 degrees 35 minutes 29.81 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 8 to 10 degrees C
Depth to seasonal high water table - 90 to 180 cm
Rock fragments - 0 to 15 percent gravel
Note: where cultivated, saturation is, in part, from intensive flood irrigation.
A horizon:
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4
Texture: loam, sandy clay loam or clay loam
Clay content: 18 to 30 percent
Rock fragments: 0 to 15 percent gravel
Electrical conductivity: 2 to 8 mmhos/cm
Reaction: 7.4 to 8.0
Bt horizons:
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 4 or 5
Texture: sandy clay loam, clay loam or loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 15 percent gravel
Electrical conductivity: 2 to 8 mmhos/cm
Reaction: 7.4 to 8.0
C horizons:
Hue: 7.5YR to 2.5Y
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3, 4 or 5
Texture: sandy loam or fine sandy loam
Clay content: 10 to 18 percent
Electrical conductivity: 2 to 4 mmhos/cm
Rock fragments: 0 to 15 percent gravel
Reaction: 7.4 to 7.8
Btb horizon:
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 4 or 5
Texture: sandy clay loam, clay loam, silty clay loam or loam
Clay content: 20 to 35 percent
Electrical conductivity: 2 to 8 mmhos/cm
Rock fragments: 0 to 15 percent gravel
Reaction: 7.4 to 7.8
COMPETING SERIES:
Jimmerfield (WY) - have horizons of secondary calcium carbonate accumulation; have hues redder than 7.5YR
Manzanar (CA) - have horizons of strong gleying; have a lithologic discontinuity
Sheetsflat (WY) - have horizons of secondary calcium carbonate accumulation below the surface mantle
Snydersditch (WY) - have horizons of secondary calcium carbonate accumulation
GEOGRAPHIC SETTING:
Landform - alluvial fans and stream terraces
Elevation - 1,085 to 1,500 meters
Slope - 0 to 8 percent slopes
Parent material - alluvium
Mean annual precipitation - 127 to 229 mm
Mean annual air temperature - 6 to 8 degrees C
Frost-free period - 110 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS: None
DRAINAGE AND PERMEABILITY: Moderately well drained; moderate to moderately rapid permeability.
USE AND VEGETATION: Roachgulch soils are used mainly for irrigated alfalfa and grass hay, although some areas are cultivated with dry edible beans, sugar beets, silage corn, and barley.
DISTRIBUTION AND EXTENT: Roachgulch soils are of small extent in northwest Wyoming. MLRA 32.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Park County, Wyoming; 2016. The name is taken from a local landscape feature.
REMARKS:
Ochric epipedon - from 0 to 20 cm (Ap horizon)
Argillic horizon - from 20 to 60 cm (Bt1 and Bt2 horizons)
Redoximorphic concentrations - from 42 to 200 cm (Bt2, C, Btb and C' horizons)
Redoximorphic depletions - from 42 to 200 cm (Bt2, C, Btb and C' horizons)
Particle-size control section - from 20 to 60 cm (Bt1 and Bt2 horizons)
Roachgulch soils have a mesic temperature regime and an aridic moisture regime.
National Cooperative Soil Survey
U.S.A.