LOCATION REEDWEST MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Reedwest loam, in cropland. (Colors are for dry soil unless otherwise noted)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure parting to weak medium and fine granular; soft, very friable, slightly sticky and slightly plastic; common fine and very fine and few medium roots; many fine pores; slightly alkaline (pH 7.6); abrupt smooth boundary. (5 to 10 inches thick)
Bt1--6 to 13 inches; dark grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; many fine pores; common distinct clay films on faces of peds and lining pores; slightly alkaline (pH 7.6); clear smooth boundary.
Bt2--13 to 19 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; few fine and very fine roots; common fine and very fine pores; common distinct clay films on faces of peds and lining pores; slightly alkaline (pH 7.6); gradual wavy boundary. (Combined thickness of Bt horizons is 6 to 20 inches.)
Bk--19 to 27 inches; light brownish gray (2.5Y 6/2) loam, grayish brown (2.5Y 5/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; many fine pores; common medium masses of lime; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 20 inches thick)
Cr--27 to 60 inches; soft calcareous sandstone.
TYPE LOCATION: Sweet Grass County, Montana; 200 feet south and 1,300 feet east of the nortwest corner of section 33, T. 5 N., R. 15 E.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 41 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 15 inches.
Depth to Bk horizon - 11 to 30 inches.
Depth to Cr horizon - 20 to 40 inches.
A horizon - Hue: 10YR or 2.5Y
Value: 3, 4, or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Texture: loam, silt loam or clay loam
Clay content: 15 to 33 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles or channers
Reaction: pH 6.1 to 7.8
Bt horizons - Hue: 10YR or 2.5Y
Value: 4, 5, or 6 dry; 2, 3, 4, or 5 moist
Chroma: 2, 3, or 4
Texture: loam, sandy clay loam, or clay loam
Clay content: 18 to 35 percent clay
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles or channers
Reaction: pH 6.6 to 7.8
Bk horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 6, 7, or 8 dry; 4, 5 or 6 moist
Chroma: 2, 3, or 4
Texture: loam, clay loam, fine sandy loam or sandy clay loam
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles; 0 to 10 percent pebbles or channers
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Absarook (MT) - has a lithic contact at 20 to 40 inches.
Beartooth (MT) - does not have a paralithic contact above 60 inches; has loamy-skeletal material directly underlying the argillic horizon.
Beeno (WY) - has a Btk horizon.
Bielenberg (MT) - has a paralithic contact at 40 to 58 inches; does not have horizon of secondary carbonate accumulation.
Bookcliff (UT) - has a lithic contact at 40 to 60 inches.
Burtoner (MT) - has a lithic contact at 23 to 40 inches.
Clancy (MT) - has a lithic contact at 40 to 60 inches; does not have horizon of secondary carbonate accumulation.
Clasoil (MT) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation.
Dooley (MT) - does not have a paralithic contact above 60 inches.
Empedrado (CO) - does not have a paralithic contact above 40 inches.
Fairfield (MT) - does not have a paralithic contact above 60 inches; has a calcic horizon.
Farnuf (MT) - does not have a paralithic contact above 60 inches.
Felor (SD) - does not have a paralithic contact above 40 inches.
Greenway (SD) - does not have a paralithic contact above 60 inches.
Gurney (SD) - has a lithic contact at 20 to 40 inches.
Hangdo (UT) - does not have a paralithic contact above 60 inches.
Hoppers (MT) - has a lithic contact at 20 to 40 inches.
Hyalite (MT) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation; has a sandy-skeletal discontinuity above a depth of 40 inches.
Jeffcity (MT) - has a lithic contact at 23 to 40 inches.
Kokoruda (MT) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation.
Livona (ND) - does not have a paralithic contact above 40 inches.
Martinsdale (MT) - does not have a paralithic contact above 60 inches.
Maudlin (CO) - has a lithic contact at 20 to 40 inches.
Meagher (MT) - does not have a paralithic contact above 60 inches.
Moen (CO) - has a lithic contact at 20 to 40 inches; does not have horizon of secondary carbonate accumulation.
Pianohill (MT) - has a lithic contact at 20 to 40 inches; does not have horizon of secondary carbonate accumulation.
Placerton (MT) - has a lithic contact at 40 to 60 inches.
Reeder (ND) - is at elevations of less than 3,600 feet.
Snakejohn (UT) - has a lithic contact at 40 to 60 inches.
Sponseller (AZ) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation.
Tragmon (CO) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation.
Trazuni (NM) - does not have a paralithic contact above 60 inches; does not have horizon of secondary carbonate accumulation.
Ulrant (WY) - does not have a paralithic contact above 60 inches.
Vida (MT) - does not have a paralithic contact above 60 inches.
Watne (MT) - does not have a paralithic contact above 60 inches.
Watrous (ND) - has a lithic contact at 20 to 40 inches.
Wemple (MT) - does not have a paralithic contact above 60 inches.
Williams (ND) - does not have a paralithic contact above 60 inches.
Yegen (MT) - does not have a paralithic contact above 60 inches.
GEOGRAPHIC SETTING:
Landform - sedimentary plains, hills, dikes, escarpments.
Elevation - 3,600 to 6,200 feet.
Parent material - material weathered from sedimentary beds.
Slope - 0 to 60 percent.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 15 to 19 inches.
Mean annual air temperature - 39 to 45 degrees F.
Frost-free period - 70 to 120 days.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Used mainly for cropland, hayland and rangeland. Native vegetation is bluebunch wheatgrass, needleandthread, western wheatgrass, Idaho fescue, big sagebrush and numerous forbs.
DISTRIBUTION AND EXTENT: Reedwest soils are of large extent in south central Montana.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gallatin County, Montana, 1997; Proposed in Sweet Grass County, Montana, 1996.
REMARKS: Soil Interpretations Record MT1621. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 13 inches (Ap, Bt1 horizons); an argillic horizon from 6 to 19 inches (Bt1, Bt2 horizons); a horizon of secondary carbonate accumulation from 19 to 27 inches (Bk horizon); a paralithic contact at 27 inches (Cr horizon). Reedwest soils have a frigid temperature regime and an ustic moisture regime.