LOCATION DYCE MT

Established Series
REV. KTS-GFB-RJS
01/2012

DYCE SERIES

The Dyce series consists of moderately deep, well drained soils that formed in colluvium, slide deposits and/or residuum derived from interbedded shale, siltstone and sandstone. These soils are on hills, escarpments and landslides. Slopes are 0 to 60 percent. Mean annual precipitation is about 330 mm, and the mean annual air temperature is about 4 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Aridic Paleustalfs

TYPICAL PEDON: Dyce loam, in rangeland (colors are for dry soil unless otherwise noted).

A--0 to 5 cm; light olive brown (2.5Y 5/3) loam, dark olive brown (2.5Y 3/3) moist; moderate fine and medium platy structure parting to weak very fine and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; many very fine and fine vesicular pores throughout; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (5 to 10 cm thick)

Bt--5 to 28 cm; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; strong medium and coarse subangular blocky structure; extremely hard, very firm, very sticky and very plastic; common very fine and fine roots throughout; common very fine and fine dendritic tubular pores throughout; many prominent clay films on faces of peds; 5 percent gravel; slightly alkaline (pH 7.6); gradual wavy boundary. (15 to 40 cm thick)

Btk--28 to 43 cm; light yellowish brown (2.5Y 6/3) clay loam, olive brown (2.5Y 4/3) moist; moderate medium subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; common very fine and fine roots throughout; common very fine and fine dendritic tubular pores throughout; many distinct clay films on faces of peds; 5 percent gravel; finely disseminated calcium carbonate and many fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (0 to 36 cm thick)

Bk--43 to 66 cm; light yellowish brown (2.5Y 6/3) loam, olive brown (2.5Y 4/3) moist; weak medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine and fine roots throughout; common very fine and fine dendritic tubular pores throughout; 5 percent gravel; finely disseminated calcium carbonate and many fine and medium patchy soft masses and threads of calcium carbonate throughout; strongly effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (15 to 40 cm thick)

Cr--66 cm; semi-consolidated mixed sedimentary beds.

TYPE LOCATION: Beaverhead County, Montana; Mill Point topographic quadrangle. UTM 12T, 3355627e, 5001591n; 183 meters north and 152 meters west of the SE corner of sec. 8, T. 8 S., R 12 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 4 to 8 degrees C.
Ochric epipedon thickness - 5 to 10 cm
Depth to argillic horizon - 5 to 10 cm
Depth to secondary calcium carbonate accumulation - 15 to 30 cm
Depth to a paralithic contact - 50 to 100 cm

Note: Some pedons may have an E and/or BC horizon.

A horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Clay content: 15 to 27 percent
Rock fragments: 0 to 40 percent--0 to 20 percent gravel, 0 to 20 percent cobbles
Reaction: pH 6.6 to 7.4

Bt horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: silty clay loam or clay
Clay content: 35 to 50 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 7.4 to 7.9

Btk horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: clay loam or silty clay loam
Clay content: 30 to 40 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.9 to 8.4

Bk horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 to 4; dry or moist
Texture: loam, sandy clay loam or silt loam
Clay content: 10 to 27 percent
Rock Fragments: 0 to 35 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.6

COMPETING SERIES:
Deepone (MT) - is very deep

GEOGRAPHIC SETTING:
Landform - hills, escarpments and landslides
Elevation - 1790 to 1985 meters
Slope - 0 to 60 percent
Parent material - colluvium, slide deposits and/or residuum derived from interbedded shale, siltstone and sandstone
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 250 to 360 mm
Mean annual air temperature - 3.5 to 7 degrees C.
Frost-free period - 70 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Cabbart, Delpoint, Udecide and Varney soils. The Cabbart soils are mostly on ridges and are shallow and loamy. The moderately deep Delpoint and Udecide soils are on similar landscape positions as the Dyce soils but are fine-loamy and formed from siltstone or sandstone materials. The Varney soils are very deep and are in valley or drainage positions, they are fine-loamy, and formed from alluvium.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Dyce soils are used mainly for rangeland and wildlife habitat. Potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, prairie junegrass, poa (species), prickly pear cactus, big sagebrush, and other grasses and forbs.

DISTRIBUTION AND EXTENT: Dyce soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2004.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 0 to 5 cm (A horizon)
Argillic horizon - from 5 to 43 cm (Bt and Btk horizons)
Horizons with secondary calcium carbonate accumulation - from 28 to 66 cm (Btk and Bk horizons)
Paralithic contact - at 66 cm (Cr horizon)
Pale great group feature - An absolute increase in clay of more than 20 percent within a vertical distance of 7.5 cm at the upper boundary of the Bt horizon
Particle-size control section - from 5 to 43 cm (Bt and Btk horizons)

Dyce soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.

Additional Information: Classification was updated from Aridic Haplustalfs to Aridic Paleustalfs (02/27/2008).

National Cooperative Soil Survey
U.S.A.