LOCATION UDECIDE MT
Established Series
Rev. DES/GFB/SJJ
04/2016
UDECIDE SERIES
The Udecide soils consists of moderately deep, well drained soils that formed in alluvium, colluvium, or residuum derived from weakly consolidated siltstone, loamstone, and sandstone. These soils are on alluvial fans, interfluves, hills, knolls, escarpments, strath terraces and sedimentary plains. Slopes are 2 to 45 percent. Mean annual precipitation is about 12 inches, and mean annual air temperature is about 42 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Udecide sandy clay loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 5 inches; grayish brown (10YR 5/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial and tubular pores; 5 percent pebbles; neutral (pH 7.0); clear wavy boundary. (4 to 8 inches thick)
Bt1--5 to 9 inches; dark grayish brown (10YR 4/2) sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial and tubular pores; common distinct dark brown (10YR 3/3) clay films on faces of peds and bridging sand grains; 5 percent pebbles; neutral (pH 7.2); clear wavy boundary.
Bt2--9 to 14 inches; grayish brown (10YR 5/2) loam, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial and tubular pores; common distinct dark brown (10YR 3/3) clay films on faces of peds and bridging sand grains; 5 percent pebbles; neutral (pH 7.2); gradual wavy boundary. (Combined thickness of Bt horizons is 6 to 15 inches).
Bk1--14 to 20 inches; light brownish gray (10YR 6/2) gravelly loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial and tubular pores; 15 percent pebbles; disseminated lime; common fine masses and threads of lime; few faint light gray (10YR 7/1) lime coatings on undersides of pebbles; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary.
Bk2--20 to 28 inches; light brownish gray (10YR 6/2) gravelly sandy clay loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; common very fine and fine interstitial and tubular pores; 15 percent pebbles; disseminated lime; common medium masses and threads of lime; common distinct lime coatings on undersides of pebbles; violently effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (Combined thickness of Bk horizons is 8 to 20 inches)
Cr--28 to 60 inches; light brownish gray (2.5Y 6/2) weakly consolidated sandstone that crushes to loamy sand.
TYPE LOCATION: Jefferson County, Montana; 2,100 feet north and 2,600 feet east of the SW corner of sec. 29, T. 2 N., R. 1 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 47 degrees F.
Moisture control section - between 4 and 12 inches, dry in some part for six-tenths or more of the cumulative days per year when the soil temperature at 20 inches is 41 degrees or higher.
Mollic epipedon thickness- 7 to 10 inches.
Depth to argillic horizon - 4 to 8 inches.
Depth to the Bk horizon - 10 to 23 inches.
Depth to Cr horizon - 20 to 40 inches.
A horizon - Hue: 10YR or 2.5Y
Value: 2 or 3 moist
Chroma: 2 or 3
Texture: sandy clay loam, clay loam, silt loam or sandy loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 35 percent--0 to 20 percent cobbles, 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
Bt horizons - Hue: 7.5YR, 10YR, or 2.5Y
Value: 4, 5, or 6 dry; 3 or 4 moist
Chroma: 2, 3 or 4
Texture: loam, clay loam, or sandy clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 20 percent--0 to 5 percent cobbles, 0 to 15 percent pebbles
Reaction: pH 6.6 to 7.8
Bk horizons - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3 or 4
Texture: loam, sandy loam, or sandy clay loam
Clay content: 10 to 30 percent
Rock fragments: 0 to 30 percent--0 to 5 percent cobbles, 0 to 25 percent pebbles
Calcium carbonate equivalent: 10 to 20 percent
Reaction: pH 7.9 to 8.4
Cr horizon - interbedded semiconsolidated sandstone, siltstone, and loamstone. It may also contain thin strata of semiconsolidated shale.
COMPETING SERIES:
Assinniboine (MT) - has fine sandy loam, loamy fine sand, or fine sand C horizons; does not have a paralithic contact above a depth of 60 inches.
Beavwan (MT) - has a discontinuity of sandy-skeletal material above a depth of 40 inches; does not have a paralithic contact above a depth of 60 inches.
Berlake (CO) - does not have a lithological discontinuity above a depth of 40 inches; noncalcareous to a depth of 30 inches; does not have a paralithic contact above a depth of 60 inches.
Bostwick (CO) - is noncalcareous to depths of 30 inches or more; does not have a paralithic contact above a depth of 60 inches.
Cheesman (CO) - has hues of 5YR or redder.
Crittenden (MT) - has a sandy-skeletal 2C horizon; does not have a paralithic contact above a depth of 60 inches.
Duffson (CO) - has lithic bedrock (R) at depths of 20 to 40 inches.
Eapa (SD) - has less than 45 percent sand in the Bt horizon; does not have a paralithic contact above a depth of 60 inches.
Evanot (CO) - does not have a paralithic contact above a depth of 60 inches.
Evanston (WY) - has less than 45 percent sand in the Bt horizon; does not have a paralithic contact above a depth of 60 inches.
Jarre (CO) - is noncalcareous to depths of 30 inches or more; does not have a paralithic contact above a depth of 60 inches.
Joplin (MT) - has less than 45 percent sand in the Bt horizon; is less than 10 inches to the base of the argillic horizon; does not have a paralithic contact above a depth of 60 inches.
Kenilworth (MT) - has a discontinuity of till at depths of 10 to 20 inches; does not have a paralithic contact above a depth of 60 inches.
Kevin (MT) - has less than 45 percent sand in the Bt horizon; is less than 10 inches to the base of the argillic horizon; does not have a paralithic contact above a depth of 60 inches.
Marmarth (ND) - does not have coarse fragments in the Bt or Bk horizons; has a stony phase; is at elevations under 3,800 feet; requires more than 400 cooling degree days.
Perrypark (CO) - is noncalcareous to depths of 30 inches or more; does not have a paralithic contact above a depth of 60 inches.
Peyton (CO) - is noncalcareous to depths of 30 inches or more; does not have a paralithic contact above a depth of 60 inches.
Reicess (WY) - does not have a lithological discontinuity above a depth of 40 inches; does not have a paralithic contact above a depth of 60 inches.
Sugakool (WY) - does not have a lithological discontinuity above a depth of 40 inches; has 5YR and redder hues; does not have a paralithic contact above a depth of 60 inches.
Telstad (MT) - has less than 45 percent sand in the Bt horizon; does not have a paralithic contact above a depth of 60 inches.
Turret (CO) - is noncalcareous to depths of 30 inches or more; does not have a paralithic contact above a depth of 60 inches.
GEOGRAPHIC SETTING:
Landform - alluvial fans; hills; knolls; interfluves; escarpments; strath terraces; sedimentary plains.
Elevation - 3,800 to 6,200 feet.
Slope - 2 to 45 percent.
Parent material - alluvium, colluvium, or residuum derived from weakly consolidated siltstone, loamstone, and sandstone.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 70 to 115 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability.
USE AND VEGETATION: Udecide soils are primarily used for rangeland and cropland. The potential native vegetation is mainly bluebunch wheatgrass, Western wheatgrass, blue grama, prairie junegrass, rubber rabbitbrush, and big sagebrush.
DISTRIBUTION AND EXTENT: Udecide soils are of small extent in southwestern Montana. MLRA 44.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gallatin County, Montana, 1997; proposed in Jefferson County, Montana, 1993.
REMARKS: Soil interpretation record: MT1585, MT1611. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the surface to 9 inches (A, Bt1 horizons); an argillic horizon from 5 to 14 inches (Bt1, Bt2 horizons); horizons of secondary calcium carbonate accumulation from 14 to 28 inches (Bk1, Bk2 horizons); weakly consolidated sandstone bedrock at 28 inches (Cr horizon); a particle-size control section from 5 to 14 inches (Bt1, Bt2 horizons). Udecide soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
National Cooperative Soil Survey
U.S.A.