LOCATION WINIFRED           MT+CO
Established Series
Rev. GFB-DRS-CJH
10/1999

WINIFRED SERIES


The Winifred series consists of moderately deep, well drained soils that formed in residuum weathered from semiconsolidated shale or in alluvium over the deposited semiconsolidated shale. These soils are on sedimentary plains, hills, and escarpments. Slopes are 0 to 65 percent. Mean annual precipitation is about 17 inches, and mean annual air temperature is about 42 degrees F.

TAXONOMIC CLASS: Fine, smectitic, frigid Entic Haplustolls

TYPICAL PEDON: Winifred silty clay loam, rangeland (colors are for dry soil unless otherwise noted).

A1--0 to 3 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine granular structure; slightly hard, friable, sticky and plastic; many fine and very fine roots; many very fine pores; neutral (pH 7.0); clear wavy boundary. (2 to 4 inches thick)

A2--3 to 6 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to moderate fine subangular blocky; hard, friable, sticky and plastic; many fine and very fine roots; many very fine pores; neutral (pH 7.2); clear wavy boundary. (3 to 8 inches thick)

Bw--6 to 14 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to strong fine subangular blocky; very hard, friable, sticky and plastic; common fine and many very fine roots; many very fine pores; few fine threads and masses of lime; disseminated lime; strongly effervescent; slightly alkaline (pH 7.8); gradual irregular boundary. (6 to 12 inches thick)

Bk1--14 to 22 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; strong medium prismatic structure parting to moderate medium and fine subangular blocky; very hard, friable, sticky and plastic; common fine and many very fine roots; many very fine pores; common medium masses of lime; strongly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (5 to 15 inches thick)

Bk2--22 to 32 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and coarse prismatic structure parting to weak medium subangular blocky; very hard, firm, sticky and plastic; few very fine roots; common very fine pores; common medium masses of lime; strongly effervescent; slightly alkaline (pH 7.8); gradual wavy boundary. (4 to 15 inches thick)

Cr--32 to 60 inches; grayish brown and yellowish brown mudstone; slightly effervescent; slightly alkaline (pH 7.6).

TYPE LOCATION: Fergus County, Montana; 900 feet north and 800 feet west of the SE corner of sec. 9, T. 15 N., R. 18 E.

RANGE IN CHARACTERISTICS:

Soil temperature - 42 to 47 degrees F.

Moisture control section - between 4 and 12 inches.

Mollic epipedon thickness - 7 to 15 inches.

Depth to bedrock - 20 to 40 inches.

Depth to Bk horizon - 11 to 22 inches.

Some pedons have a BC horizon.

A horizons - Hue: 10YR or 2.5Y

Value: 3, 4, or 5 dry; 2 or 3 moist

Chroma: 2 or 3

Texture: clay loam, silty clay loam, or clay

Clay content: 27 to 50 percent

Rock fragments: 0 to 35 percent--0 to 20 percent cobbles, 0 to 15 percent pebbles

Reaction: pH 6.6 to 7.8

Bw horizon - Hue: 10YR or 2.5Y

Value: 4 or 5 dry, 3 or 4 moist

Chroma: 2 or 3

Texture: clay loam, silty clay, clay, silty clay loam

Clay content: 35 to 50 percent

Rock fragments: 0 to 15 percent--0 to 10 percent cobbles, 0 to 5 percent pebbles

Effervescence: none to strongly

Reaction: pH 7.4 to 8.4

Bk horizons - Hue: 10YR or 2.5Y

Value: 5, 6, or 7 dry; 4, 5, or 6 moist

Chroma: 2 or 3

Texture: clay, silty clay, silty clay loam, clay loam

Clay content: 35 to 50 percent

Rock fragments: 0 to 15 percent--0 to 10 percent cobbles, 0 to 5 percent pebbles

Calcium carbonate equivalent: 5 to 15 percent

Reaction: pH 7.4 to 9.0

COMPETING SERIES:

Dapoin (CO) - does not have a paralithic contact above a depth of 40 inches.

Linwell (MT) - does not have a paralithic contact above a depth of 40 inches.

GEOGRAPHIC SETTING:

Landform - sedimentary plains, hills, and escarpments.

Elevation - 2,000 to 5,000 feet. Elevation up to 6,200 feet is allowed in the foothills of the mountains and from 7,600 to 8,400 feet in Colorado.

Slope- 0 to 65 percent.

Parent material - residuum weathered from semiconsolidated shale or in alluvium deposited over the shale.

Climate - long, cold winters; moist springs and summers

Mean annual precipitation - 15 to 19 inches.

Mean annual air temperature - 39 to 45 degrees F.

Frost-free period - 90 to 125 days. It ranges down to 70 days in the foothills of the mountains.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Winifred soils are used mainly for nonirrigated cropland and rangeland. Potential native vegetation is mainly green needlegrass, western wheatgrass, bluebunch wheatgrass, Sandberg bluegrass, prairie junegrass, fringed sagewort, and big sagebrush.

DISTRIBUTION AND EXTENT: Winifred soils are extensive in central Montana.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Reconnaissance Soil Survey of central Montana, 1942.

REMARKS: Soil interpretations records: MT0135, MT0820.

Diagnostic horizons and features recognized in this pedon are: mollic epipedon - from the soil surface to 7 inches, mixed (A1, A2, and part of Bw horizon); cambic horizon - from 6 to 14 inches (Bw horizon); horizons of secondary carbonate accumulation - from 14 to 32 inches (Bk1, Bk2 horizon); paralithic contact - at a depth of 32 inches (Cr horizon); particle-size control section - from 10 to 32 inches (Bw, Bk1, Bk2 horizons). Winifred soils have a frigid temperature regime and an ustic moisture regime.


National Cooperative Soil Survey
U.S.A.