LOCATION VOLDSETH MT

Tentative Series
REV. DJP/EMM
09/2014

VOLDSETH SERIES

The Voldseth series consists of very deep, somewhat poorly drained soils that formed in alluvium or colluvium derived from sedimentary, igneous, or metamorphic rock. These soils are on stream terraces, alluvial fans and valley floors in intermontane basins. Slopes are 0 to 8 percent. Mean annual precipitation is about 400 mm, and mean annual temperature is about 5 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Oxyaquic Argiustolls

TYPICAL PEDON: Voldseth loam, 4 percent slope in irrigated cropland at an elevation of 1680 meters (colors are for dry soil unless otherwise noted).

Ap--0 to 14 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium and fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots throughout; many very fine and fine irregular pores throughout; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (8 to 16 cm thick)

Bt1--14 to 24 cm; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common very fine and fine, few medium roots throughout; many very fine and fine tubular and interstitial pores; 60 percent distinct clay films on faces of peds; 5 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary.

Bt2--24 to 60 cm; light brownish gray (10YR 6/2) clay loam, dark grayish brown (10YR 4/2) moist; strong coarse subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; many very fine tubular and interstitial pores; 40 percent clay films on faces of peds; 10 percent gravel; moderately alkaline (pH 8.0); clear smooth boundary. (combined thickness of Bt horizons is 28 to 70cm thick)

Bk1--60 to 84 cm; light gray (10YR 7/2) gravelly silt loam, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; moderately hard, firm, slightly sticky and slightly plastic; common very fine roots; many very fine tubular and interstitial pores; 20 percent gravel; strongly effervescent, 10 percent fine carbonate masses in matrix and 40 percent fine carbonate concentrations on bottom of rock fragments, 18 percent calcium carbonate equivalent; 20 percent fine prominent dark yellowish brown (10YR 4/6) redox concentrations and 15 percent fine distinct light brownish gray (10YR 6/2) redox depletions; moderately alkaline (pH 8.4); gradual smooth boundary. (22 to 42 cm thick)

Bk2--84 to 150 cm; very pale brown (10YR 7/3) very gravelly loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; 45 percent gravel; violently effervescent, 20 percent fine carbonate masses in matrix, 50 percent fine carbonate concentrations on bottom of rock fragments and 22 percent calcium carbonate equivalent; 15 percent fine prominent dark yellowish brown (10YR 4/6) redox concentrations and 10 percent fine distinct light gray (10YR 7/2) redox depletions; strongly alkaline (pH 8.6).

TYPE LOCATION: Meagher County, Montana; about 8 miles southwest of Martinsdale; located about 600 feet north and 580 feet east of the SW corner of sec. 18, T. 7 N., R. 11 E; Lebo topographic quad; lat. 46 degrees 21 minutes 39 seconds N. and long. 110 degrees 24 minutes 19 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Soil Moisture: The soil moisture control section is moist December to August from natural precipitation events and from irrigation practices; driest September to November; ustic moisture regime.
Mean Annual Soil Temperature: 4 to 7 degrees C.
Depth to anthric saturation: 60 to 90 cm from June to August. Seepage from irrigation canals is the source of the water.
Mollic epipedon thickness: 20 to 30 cm.
Depth to Bk horizons: 40 to 60 cm.
Depth to loamy-skeletal material: 74 to 94 cm.

A horizon:
Hue: 10YR or 2.5Y
Value: 3 to 5 dry; 2 or 3 moist
Chroma: 2 or 3, dry or moist
Clay content: 16 to 26 percent
Rock fragment content: 0 to 15 percent; 0 to 10 percent cobbles and stones; 0 to 15 percent gravel
Reaction: pH 6.6 to 7.6

Bt1 horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6 dry; 3 or 4 moist
Chroma: 2 to 4, dry or moist
Texture: loam or clay loam
Clay content: 22 to 34 percent
Rock fragments: 0 to 15 percent; 0 to 5 percent cobbles; 0 to 15 percent gravel
Reaction: pH 6.8 to 7.8

Bt2 horizon:
Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 2 to 4, dry or moist
Texture: loam or clay loam
Clay content: 24 to 35 percent
Rock fragments: 0 to 15 percent; 0 to 5 percent cobbles; 0 to 15 percent gravel
Reaction: pH 7.0 to 8.0

Some pedons have a thin Btk horizon.

Bk1 horizon:
Hue: 10YR or 2.5Y
Value: 6 to 8 dry; 4 to 7 moist
Chroma: 2 to 4, dry or moist
Texture: silt loam or loam
Clay content: 18 to 30 percent
Calcium carbonate equivalent: 15 to 40 percent
Rock fragments: 15 to 35 percent; 0 to 15 percent cobbles; 15 to 35 percent gravel
Reaction: pH 8.0 to 8.5

Bk2 horizon:
Hue: 10YR or 2.5Y
Value: 6 to 8 dry; 4 to 7 moist
Chroma: 2 to 4 dry or moist
Texture: silt loam or loam,
Clay content: 12 to 26 percent
Calcium carbonate equivalent: 15 to 40 percent
Rock fragments: 35 to 60 percent--0 to 10 percent cobbles; 35 to 60 percent gravel
Reaction: pH 8.2 to 8.5

COMPETING SERIES:
Chivers (UT) - has hues redder then 10YR.
Fuertes (CO) - do not have a calcic horizon.
Groveland (MT) - does not have a loamy-skeletal subsoil.
Millburne (WY) - occurs at elevations above 2040 meters.

GEOGRAPHIC SETTING:
Parent material: alluvium or colluvium derived from sedimentary, igneous, and metamorphic rock
Landform: stream terraces, alluvial fans, and valley floors
Slope: 0 to 8 percent
Elevation: 1,400 to 1,950 meters
Climate: long, cold winters; moist springs; short summers
Mean annual temperature: 3 to 7 degrees C.
Mean annual precipitation: 350 to 480 millimeters
Precipitation Pattern: precipitation falls most during spring and early summer
Frost-free period: 70 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Groveland, Hereimcreek, Martinsdale, and Meagher soils. The Groveland soils do not have a loamy-skeletal subsoil and are on similar positions. The Hereimcreek soils have gleyed horizons and are on terrace treads and drainageways. Martinsdale and Meagher soils do not have redox features.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained, low runoff, moderately slow permeability.

USE AND VEGETATION: Voldseth soils are used for rangeland and irrigated and nonirrigated cropland. The potential native vegetation is mainly rough fescue, bluebunch wheatgrass, Idaho fescue, green needlegrass, needleandthread, western wheatgrass, Sandberg bluegrass, prairie junegrass, forbs, and shrubs.

DISTRIBUTION AND EXTENT: Voldseth soils are of small extent in west-central Montana. MLRA 43B, 44B, and 46.

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

SERIES PROPOSED: Meagher County, Montana 2007. The Voldseth name is a named reservoir on the Lennep Topographic Quadrangle.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 24 cm (Ap and Bt1 horizons).
Argillic horizon - the zone from 14 to 60 cm (Bt1 and Bt2 horizons).
Calcic horizon - the zone from 60 to 150 cm (Bk1 and Bk2 horizons).
Particle-size control section - the zone from 14 to 60 cm (Bt1 and Bt2 horizons).

Voldseth soils have a frigid temperature regime and an ustic moisture regime.

Redoxomorphic features attributed to irrigation practices.

Taxonomic Version: Tenth Edition, 2006.

National Cooperative Soil Survey
U.S.A.