LOCATION KENILWORTH MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Argiustolls
TYPICAL PEDON: Kenilworth fine sandy loam, cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 5 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; neutral (pH 6.6); abrupt smooth boundary. (5 to 8 inches thick)
Bt1--5 to 8 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine tubular pores; common faint clay films on prism faces; neutral (pH 6.8); clear smooth boundary. (0 to 4 inches thick)
Bt2--8 to 12 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 4/3) moist; moderate medium and coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine tubular pores; many faint clay films on prism faces; neutral (pH 6.8); clear wavy boundary. (5 to 10 inches thick)
2Bt3--12 to 16 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate medium prismatic structure parting to moderate fine and medium subangular blocky; hard, friable, sticky and plastic; few very fine roots; many very fine tubular pores; many faint clay films on faces of peds; neutral (pH 6.8); gradual wavy boundary. (0 to 4 inches thick)
2Bk1--16 to 29 inches; light brownish gray (10YR 6/2) clay loam, grayish brown (10YR 5/2) moist; weak medium prismatic structure parting to moderate fine and medium subangular blocky; hard, friable, sticky and plastic; few very fine roots; many very fine tubular pores; many medium and coarse masses of lime; violently effervescent, mildly alkaline (ph 7.8); gradual wavy boundary. (10 to 22 inches thick).
2Bk2--29 to 60 inches; light brownish gray (2.5YR 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate fine and medium angular blocky structure; hard, firm, sticky and plastic; common very fine tubular pores; few fine masses of lime in the upper part, strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Chouteau County, Montana; 2,000 feet north and 1,400 feet west of the SE corner of sec. 21, T. 28 N., R. 11 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 15 inches.
Depth to 2Bk and lithologic discontinuity - 10 to 26 inches.
BC, C, or 2Bky horizons are allowed.
Ap horizon - Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: fine sandy loam, sandy loam, loam, or sandy clay loam
Clay content: 5 to 25 percent
Reaction: pH 6.6 to 7.8
Bt1 horizon - Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3
Texture: fine sandy loam or sandy clay loam
Clay content: 15 to 25 percent and more than 45 percent fine and coarser sand
Reaction: pH 6.6 to 7.8
Bt2 horizon - Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2, 3, or 4
Texture: sandy clay loam, fine sandy loam, or loam
Clay content: 18 to 30 percent and more than 45 percent fine and coarser sand
Reaction: pH 6.6 to 7.8
Bulk density: 1.40 to 1.60
2Bt3 horizon - Chroma: 3 or 4
Texture: sandy clay loam or clay loam
Clay content: 20 to 35 percent and 20 to more than 45 percent fine and coarser sand
Reaction: pH 6.6 to 7.8
Bulk density: 1.40 to 1.60
2Bk1 horizon - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2, 3, or 4
Textures: clay loam or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 5 percent pebbles
Calcium carbonate equivalent - 5 to 15 percent
Reaction: pH 7.4 to 8.4
Bulk density: greater than 1.6
A fine sandy loam Bk horizon is allowed above the discontinuity.
2Bk2 horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2, 3, or 4
Textures: clay loam or silty clay loam
Clay content: 27 to 35 percent
Rock fragments: 0 to 5 percent pebbles
Calcium carbonate equivalent - 5 to 15 percent
Gypsum: 0 to 5 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Assinniboine (MT) - has fine sandy loam, loamy fine sand, or fine sand C horizons.
Beavwan (MT) - has a discontinuity of sandy-skeletal material above a depth of 40 inches.
Berlake (CO) - does not have a lithological discontinuity above a depth of 40 inches; is noncalcareous to a depth of 30 inches.
Bostwick (CO) - is noncalcareous to depths of 30 inches or more.
Cheeseman (CO) - has bedrock at depths of 20 to 40 inches and have hues of 5YR or redder.
Crittenden (MT) - has a sandy-skeletal 2C horizon.
Duffson (CO) - has bedrock at depths of 20 to 40 inches.
Eapa (SD) - has less than 45 percent sand in the Bt horizon.
Emlin (CO) - does not have a lithological discontinuity above a depth of 40 inches.
Evanston (WY) - has less than 45 percent sand in the Bt horizon.
Evanot (CO) - does not have a lithological discontinuity above a depth of 40 inches.
Jarre (CO) - is noncalcareous to depths of 30 inches or more.
Joplin (MT) - has less than 45 percent sand in the Bt horizon; is less than 10 inches to the base of the argillic horizon.
Kevin (MT) - has less than 45 percent sand in the Bt horizon; is less than 10 inches to the base of the argillic horizon.
Marmarth (ND) - has bedrock at depths of 20 to 40 inches.
Morval (NM) - has 5 to 25 percent gravel in the control section.
Notter (UT) - is skeletal below 22 inches.
Nuley (MT) - has a gravelly coarse sand 2C horizon below a depth of 15 inches; bedrock at depths of 40 to 60 inches.
Perrypark (CO) - is noncalcareous to depths of 30 inches or more.
Peyton (CO) - is noncalcareous to depths of 30 inches or more.
Reicess (WY) - does not have a lithological discontinuity above a depth of 40 inches.
Sugakool (WY) - does not have a lithological discontinuity above a depth of 40 inches; has 5YR and redder hues.
Telstad (MT) - has less than 45 percent sand in the Bt horizon.
Turret (CO) - is noncalcareous to depths of 30 inches or more.
Udecide (MT) - has a paralithic contact of semiconsolidated sandstone at depths of 20 to 40 inches.
Varney (MT) - has loamy stratified materials below depths of 23 inches.
Villa Grove (CO) - has less than 45 percent sand in the Bt horizon.
GEOGRAPHIC SETTING:
Landform - stream terraces; alluvial fans; till plains.
Elevation - 2,300 to 4,000 feet.
Slope- 0 to 8 percent.
Climate - cool with long, cold winters; moist springs; hot, dry summers.
Parent material - alluvium or in eolian and alluvial deposits over till or over glaciofluvial or glaciolacustrine deposits.
Mean annual precipitation - 10 to 14 inches, most of which falls in spring and early summer.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 105 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the upper 12 inches and slow in the lower part.
USE AND VEGETATION: Kenilworth soils are used for dryland crops and rangeland. Wheat and barley are the principal crops. The potential plant community is needleandthread, prairie sandreed, western wheatgrass, bluebunch wheatgrass, blue grama, forbs, and shrubs.
DISTRIBUTION AND EXTENT: The series is of moderate extent north-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Toole County, Montana, 1991. Series proposed in Chouteau County, Montana, 1986.
REMARKS: Soil interpretation record: MT1080. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 8 inches (Ap, Bt1 horizons); an argillic horizon from 5 to 16 inches (Bt1, Bt2, and 2Bt horizons); horizon of lime accumulation from 16 to 29 inches (2Bk horizons). Kenilworth soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.