LOCATION KEVIN MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Kevin clay loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 6 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; hard, friable, sticky and plastic; many very fine roots; many fine pores; 5 percent pebbles; slightly alkaline (pH 7.6); abrupt smooth boundary. (4 to 8 inches thick)
Bt--6 to 9 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, friable, sticky and plastic; many very fine roots; many fine pores; continuous distinct grayish brown (10YR 5/2) very dark grayish brown (10YR 3/2) moist clay films on faces of peds; 5 percent pebbles; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (3 to 5 inches thick)
Bk1--9 to 19 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist moderate medium prismatic structure parting to weak medium subangular blocky; very hard, friable, sticky and plastic; common very fine roots; many very fine pores; 5 percent pebbles with continuous thin lime crusts on surface; many very fine masses of lime; strongly effervescent; moderately alkaline (pH 8.4); gradual smooth boundary. (12 to 20 inches thick)
Bk2--19 to 30 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure; very hard, friable, sticky and plastic; common very fine roots; common very fine pores; 5 percent pebbles with continuous distinct lime crusts on surface; few lignite chips; common fine masses of lime; strongly effervescent; strongly alkaline (pH 8.6); gradual smooth boundary.
Bk3--30 to 44 inches; light brownish gray (2.5Y 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure; very hard, friable, sticky and plastic; few roots; 5 percent pebbles; few fine masses of lime; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary.
BC--44 to 60 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; massive; very hard, firm, sticky and plastic; few roots; 5 percent pebbles; few fine lignite chips; few fine masses of lime; few fine seams of gypsum; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Cascade County, Montana; 1,400 feet north and 150 feet east of the SW corner of sec. 11, T. 22 N., R. 4 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches; dry in some part six-tenths or more of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Mollic epipedon thickness - 7 to 10 inches.
Depth to Bk horizon - 7 to 10 inches.
Moist bulk density of till - 1.6 to 1.8 gram/cm
Soil phases - gravelly, very gravelly, calcareous.
A horizon - Hue: 10YR, 2.5Y, or 5Y
Chroma: 2 or 3
Texture: clay loam or loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 60 percent--0 to 50 percent pebbles, 0 to 10 percent cobbles
Reaction: pH 6.6 to 7.8
Bt horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3
Texture: clay loam or clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 15 percent
Reaction: pH 6.6 to 8.4
Bk horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent pebbles
Moist bulk density: 1.55 to 1.75 gram/cm
Calcium carbonate equivalent: .5 to 15 percent
Reaction: pH 7.4 to 9.0
BCky or Bky horizons - Hue: 10YR, 5Y, or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2, 3, or 4
Clay content: 27 to 35 percent
Rock fragments: 0 to 15 percent
Moist bulk density: 1.55 to 1.75 gram/cm
Calcium carbonate equivalent: 1 to 15 percent
Gypsum: 1 to 5 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Assinniboine (MT) - has the base of the argillic horizon deeper than 10 inches; does not have high bulk density till above 60 inches.
Berlake (CO) - is noncalcareous to a depth of 40 inches or more.
Bostwick (CO) - is noncalcareous to a depth of 40 inches or more.
Cheeseman (CO) - has bedrock at a depth of 20 to 40 inches.
Crittenden (MT) - is sandy skeletal below a depth of 25 inches.
Duffson (CO) - has bedrock at a depth of 20 to 40 inches.
Eapa (SD) - formed in alluvium or colluvium; does not have the high bulk density till above a depth of 60 inches.
Emlin (CO) - has a calcic horizon.
Evanot (CO) - has the base of the argillic horizon deeper than 10 inches; formed in eolian deposits; does not have high bulk density till above a depth of 60 inches.
Evanston (WY) - has the base of the argillic horizon deeper than 10 inches; does not have the high bulk density till above a depth of 60 inches.
Jarre (CO) - is noncalcareous to depths of 40 inches or more.
Kenilworth (MT) - has a discontinuity above a depth of 40 inches.
Joplin (MT) - has less than 35 percent clay in the argillic horizon.
Marmarth (ND) - has bedrock at a depth of 20 to 40 inches or more.
Morval (NM) - has a calcic horizon.
Notter (UT) - has a loamy-skeletal C horizon.
Nuley (MT) - has a calcic horizon; has sandy discontinuity.
Perrypark (CO) - is noncalcareous to a depth of 40 inches or more.
Peyton (CO) - is noncalcareous to a depth of 40 inches or more.
Reicess (WY) - has the base of the argillic horizon deeper than 24 inches.
Sugarkool (WY) - has hues redder than 10YR in the argillic horizon; the base of the argillic horizon is deeper than 10 inches.
Telstad (MT) - the base of the argillic horizon is deeper than 10 inches.
Turret (CO) - is noncalcareous to a depth of 40 inches or more.
Udecide (MT) - has a paralithic contact of semiconsolidated sandstone at depths of 20 to 40 inches.
Varney (MT) - has a calcic horizon.
Villa Grove (CO) - has 5 to 20 percent exchangeable sodium in the surface and in the argillic horizon.
GEOGRAPHIC SETTING:
Landform - till plains; hills.
Elevation - 2,200 to 5,000 feet.
Slope- 0 to 45 percent.
Parent material - calcareous continental till of an early or pre-Wisconsin glacial substage.
Climate - long, cold, dry winters; moist springs; moist summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 100 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Kevin soils are used mainly for nonirrigated cropland and the more strongly rolling morainic areas are used for range. Potential native vegetation is western wheatgrass, needleandthread, green needlegrass, clubmoss, and fringed sagewort.
DISTRIBUTION AND EXTENT: Kevin soils are extensive on the glaciated plains of northern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Blaine County, Montana, 1969.
REMARKS: Soil interpretations record: MT0105, MT0690.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - from the soil surface to 7 inches (mixed)(Ap, part of Bt horizons); argillic horizon - from 6 to 9 inches (Bt horizon); horizons of carbonate accumulation - (Bk1, Bk2, Bk3 horizons); particle-size control section - from 6 to 40 inches (Bt, Bk1, Bk2, Bk3 horizons). Kevin soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.