LOCATION WYOLA MT+ND SD WY

Established Series
NRS-DRS-CJH
12/2022

WYOLA SERIES

The Wyola series consists of very deep, well drained soils that formed in silty alluvium, loess, or in glaciofluvial or glaciolacustrine material. These soils are on alluvial fans, stream terraces, drainageways, sedimentary plains and till plains. Slopes are 0 to 25 percent. Mean annual precipitation is about 16 inches, and the mean annual air temperature is about 42 degrees F.

TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argiustolls

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

A--0 to 2 inches; dark grayish brown (2.5Y 4/2) silt loam, very dark grayish brown (2.5Y 3/2) moist; weak thick platy structure; hard, friable, slightly sticky and plastic; many fine and few medium roots; many fine and medium pores; slightly alkaline (pH 7.4); clear wavy boundary. (2 to 10 inches thick)

Bt1--2 to 6 inches; grayish brown (2.5Y 5/2) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate medium and coarse prismatic structure parting to moderate medium angular blocky; very hard, firm, very sticky and very plastic; common faint clay films on faces of peds; common very fine roots; common fine tubular pores; slightly alkaline (pH 7.4); clear wavy boundary.

Bt2--6 to 16 inches; dark grayish brown (2.5Y 4/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; moderate medium and coarse prismatic structure parting to strong medium angular blocky; very hard, firm, very sticky and very plastic; continuous faint clay films on faces of peds; common very fine roots; common fine tubular pores; slightly alkaline (pH 7.6); clear wavy boundary. (Combined Bt horizons 10 to 26 inches thick)

Bk1--16 to 23 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; strong coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, very firm, very sticky and very plastic; few very fine and fine roots; few fine pores; strongly effervescent; common fine threads and medium masses of lime; moderately alkaline (pH 8.0); gradual wavy boundary.

Bk2--23 to 29 inches; olive (5Y 5/3) silty clay, olive (5Y 4/3) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, very firm, very sticky and very plastic; few fine roots; common very fine and fine pores; strongly effervescent; common fine threads and medium masses of lime; moderately alkaline (pH 8.2); gradual wavy boundary.

Bk3--29 to 39 inches; olive (5Y 5/3) silty clay, olive (5Y 4/3) moist; weak medium subangular blocky structure; very hard, very firm, very sticky and very plastic; few fine roots; common fine pores; strongly effervescent; common fine threads and medium masses of lime; moderately alkaline (pH 8.2); diffuse irregular boundary.

Bk4--39 to 60 inches; pale olive (5Y 6/3) silty clay loam; olive (5Y 4/3) moist; weak coarse subangular blocky structure; few fine roots; few very fine pores; strongly effervescent; few fine masses of lime; moderately alkaline (pH 8.2) (Combined Bk horizons 25 to 48 inches thick)

TYPE LOCATION: Big Horn County, Montana; 180 feet west of trail; 860 feet east and 950 feet north of the SW corner of sec. 8, T.9 S., R. 35 E.

RANGE IN CHARACTERISTICS:

Soil temperature - 42 to 47 degrees F.

Moisture control section - between 4 and 12 inches, and are never dry in all parts for more than 30 consecutive days. Are frozen November through March.

Mollic epipedon thickness - 7 to 16 inches (may include part of all of the argillic horizon).

Depth to Bk horizon - 12 to 30 inches.

A BCk, By or C horizon is allowed.

Phases recognized--saline; PE is greater than 31; and PE is greater than 31, saline. PE is greater than 31 phase for use in North Dakota and South Dakota.

A horizon - Hue: 7.5YR, 10YR or 2.5Y

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

Chroma: 2 or 3

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

Clay content: 20 to 45 percent

Rock fragments: 0 to 5 percent pebbles

EC: 0 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm

Reaction: pH 5.6 to 7.8

Bt1 and Bt2 horizons - Hue: 7.5YR, 10YR or 2.5Y

Value: 3, 4, 5 or 6 dry; 2, 3 or 4 moist

Chroma: 2, 3 or 4

Texture: silty clay loam, silty clay or clay

Clay content: 35 to 50 percent

Rock fragments: 0 to 5 percent pebbles

EC: 0 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm

Reaction: pH 6.1 to 8.4

A Btk horizon 4 to 18 inches thick is allowed.

Bk horizons - Hue: 7.5YR, 10YR, 2.5Y or 5Y

Value: 5 or 6 dry; 4 or 5 moist

Chroma: 2, 3 or 4

Texture: silt loam, silty clay loam, silty clay or clay

Clay content: 25 to 45 percent

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

Calcium carbonate equivalent: 5 to 15 percent

EC: 0 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm

Reaction: pH 7.4 to 8.4

COMPETING SERIES:

Absarokee (MT) - bedrock between depths of 20 to 40 inches.

Acree (CO) - hues of 5YR or redder in the argillic horizon; a discontinuity in the argillic horizon.

Bearpaw (MT) - high bulk density till above depths of 40 inches.

Brolliar (AZ) - bedrock between depths of 20 to 40 inches.

Danvers (MT) - calcic horizon.

Delson (CO) - noncalcareous throughout the profile.

Herm (CO) - noncalcareous throughout the profile.

Morapos (CO) - dry in all parts of the moisture control section for 45 consecutive days after the middle of July.

Nortez (CO) - bedrock between depths of 20 to 40 inches.

Peninsula (CO) - calcic horizon.

Pramiss (CO) - bedrock between depths of 20 to 40 inches.

Quilt (UT) - noncalcareous throughout the profile.

Regent (ND) - bedrock between depths of 20 to 40 inches.

Reget (WY) - paralithic contact at depths of 20 to 40 inches.

Ricot (CO) - hues of 5YR or redder in the argillic horizon; a discontinuity in the argillic horizon.

Tamaneen (MT) - over 35 percent coarse fragments between depths of 20 and 40 inches.

Tomasaki (UT) - noncalcareous throughout the profile.

Tukuhnik (UT) - secondary carbonates deeper than 30 inches.

Work (MT) - greater than 15 percent fine sand or coarser in the control section.

GEOGRAPHIC SETTING:

Landform - alluvial fans, stream terraces, drainageways, sedimentary plains and till plains.

Elevation - 1,600 to 5,000 feet.

Slope - 0 to 25 percent.

Parent material - silty alluvium, loess, or in glaciofluvial or glaciolacustrine material.

Climate - long, cold winters; moist springs; and warm summers.

Mean annual precipitation - 14 to 19 inches.

Mean annual air temperature - 39 to 45 degrees F.

Frost-free period - 90 to 135 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Belfield, Daglum, Grail and Regent soils. Belfield, Daglum and Grail are on on similar landscape positions as the Wyola soil. Belfield and Daglum have natric horizons. Grail soils have a mollic epipedon more than 16 inches thick. Regent soils are above the Wyola soils on the landscape. They have a paralithic contact at a depth of 20 to 40 inches.

DRAINAGE AND PERMEABILITY: Well drained; slow permeability.

USE AND VEGETATION: Wyola soils are used mainly for dryland crops. Some areas are used for irrigated crops and as rangeland. Potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, green needlegrass, and perennial forbs.

DISTRIBUTION AND EXTENT: Wyola soils are extensive throughout Montana, western North Dakota and South Dakota.

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

SERIES ESTABLISHED: Lower Yellowstone Area, Montana, 1972.

REMARKS: Soil interpretations records: MT0017, MT1020, MT0252, MT0807, and MT0767.

Diagnostic horizons and features recognized in this pedon are: mollic epipedon - from the soil surface to 16 inches (Ap, Bt1, Bt2 horizons); argillic horizon and particle-size control section - from 2 to 16 inches (Bt1, Bt2 horizons). Wyola soils have a frigid temperature regime and an ustic moisture regime.

National Cooperative Soil Survey
U.S.A.