LOCATION FAIRFIELD MT+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Fairfield clay loam, cultivated (colors are for dry soil unless otherwise noted).
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; strong medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many fine pores; 5 percent pebbles; neutral (pH 6.6); clear smooth boundary. (3 to 8 inches thick)
Bt--6 to 10 inches; grayish brown (10YR 5/2) clay loam, dark brown (10YR 3/3) moist; weak medium prismatic structure parting to moderate medium angular blocky; hard, friable, moderately sticky and moderately plastic; common fine roots; common fine and very fine pores; few distinct clay films on vertical faces of peds and patchy horizontal faces of peds; 5 percent pebbles; slightly alkaline (pH 7.4); clear smooth boundary. (4 to 7 inches thick)
Bk1--10 to 17 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine roots; common fine and very fine pores; 5 percent pebbles; continuous faint lime coatings on pebbles; common fine masses of lime; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (3 to 9 inches thick)
Bk2--17 to 22 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; common fine and very fine pores; 5 percent pebbles; many distinct lime coatings on pebbles; many fine masses of lime; violently effervescent; strongly alkaline; gradual wavy boundary.
Bk3--22 to 30 inches; light yellowish brown (10YR 6/4) loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; 10 percent pebbles; many distinct lime coatings on pebbles; many fine masses of lime; violently effervescent; strongly alkaline; gradual wavy boundary. (Combined thickness of the Bk2 and Bk3 horizons is 10 to 40 inches.)
Bk4--30 to 60 inches; light gray (10YR 7/2) loam, light yellowish brown (10YR 6/4) moist; massive; hard, friable, slightly sticky and slightly plastic; many fine masses of lime; 15 percent pebbles; common faint lime coatings on pebbles, violently effervescent; strongly alkaline (pH 9.0)
TYPE LOCATION: Teton County, Montana; about 650 feet north and 2,300 feet west of the SE corner of sec. 17, T. 27 N., R. 6 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 7 to 10 inches.
Depth to calcic horizon - 7 to 10 inches.
A Btk horizon is allowed.
Soil phases - cobbly; stony; gravelly substratum.
Ap horizon - Hue: 10YR or 7.5YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: loam or clay loam
Clay content: 18 to 32 percent
Rock fragments: 0 to 35 percent--0 to 15 percent cobbles and stones, 0 to 20 percent pebbles
Rock fragments, surface cover: 0.01 to 0.1
Reaction: pH 6.6 to 8.4
Bt horizon - Hue: 2.5Y, 10YR, or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3
Texture: clay loam, loam, or silty clay loam
Clay content: 25 to 35 percent
EC: 0 to 2 mmhos/cm
Rock fragments: 0 to 35 percent--0 to 10 percent cobbles, 0 to 25 percent pebbles
Reaction: pH 6.6 to 8.4
Bk1 horizon - Hue: 2.5Y, 10YR, or 7.5YR
Value: 5, 6, 7, or 8 dry; 4, 5, 6 or 7 moist
Chroma: 2 or 3
Texture: clay loam, loam, or silty clay loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 35 percent--0 to 10 percent cobbles, 0 to 25 percent pebbles
EC: 2 to 4 mmhos/cm
Calcium carbonate equivalent: 15 to 35 percent
Reaction: pH 6.6 to 8.4
Bk2, Bk3 and Bk4 horizons - Hue: 2.5Y, 10YR, or 7.5YR
Value: 6, 7, or 8 dry; 5, 6, or 7 moist
Chroma: 2, 3, or 4
Texture: clay loam, fine sandy loam, loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 35 percent--0 to 15 percent cobbles, 0 to 20 percent pebbles
Calcium carbonate equivalent: 10 to 30 percent
EC: 2 to 4 mmhos/cm
Reaction: pH 7.4 to 9.0
COMPETING SERIES:
Absarook (MT) - has a lithic contact at a depth of 20 to 40 inches.
Beartooth (MT) - loamy-skeletal horizons below depths of 12 to 30 inches.
Beeno (WY) - paralithic contact at depths of 20 to 40 inches.
Bielenberg (MT) - does not have secondary carbonate accumulation above a depth of 40 inches.
Bookcliff (UT) - mollic epipedon thicker than 10 inches; lithic bedrock above a depth of 60 inches.
Burtoner (MT) - paralithic contact at 20 to 38 inches.
Clancy (MT) - has a lithic contact above a depth of 60 inches.
Clasoil (MT) - does not have horizons of secondary carbonate accumulation; argillic horizons are 8 to 24 inches thick.
Dooley (MT) - formed in an eolian or alluvium mantle over a discontinuity of till; base of the argillic horizon is deeper than 10 inches; does not have a calcic horizon.
Empedrado (CO) - argillic horizon with its base deeper than 10 inches; does not have a calcic horizon.
Farnuf (MT) - base of the argillic horizon is deeper than 10 inches; does not have a calcic horizon.
Felor (SD) - base of the argillic horizon is deeper than 10 inches; has a discontinuity immediately below the argillic horizon.
Greenway (SD) - has argillic horizon with its base deeper than 10 inches; discontinuity within the argillic horizon.
Gurney (SD) - lithic contact at depths of 20 to 40 inches.
Hangdo (UT) - does not have secondary carbonate accumulation above a depth of 40 inches.
Hoppers (MT) - lithic contact at 20 to 40 inches.
Hyalite (MT) - discontinuity of sandy-skeletal material above 40 inches and immediately below the argillic horizon.
Jeffcity (MT) - has lithic contact at depths of 23 to 40 inches.
Kokoruda (MT) - does not have horizons of secondary carbonate accumulation.
Livona (ND) - base of the argillic horizon is below a depth of 10 inches; discontinuity within the argillic horizon.
Martinsdale (MT) - has the base of the argillic horizon deeper than 10 inches; depth to secondary carbonates is deeper than 11 inches.
Maudlin (CO) - lithic contact at depths of 20 to 40 inches.
Meagher (MT) - has a discontinuity of loamy-skeletal material; depth to calcic horizon is deeper than 11 inches.
Moen (CO) - lithic contact at depths of 20 to 40 inches.
Pianohill (MT) - lithic contact at 20 to 40 inches.
Placerton (MT) - has a lithic contact above a depth of 60 inches.
Reeder (ND) - paralithic contact at depths of 20 to 40 inches.
Reedwest (MT) - paralithic contact at 20 to 40 inches.
Snakejohn (UT) - lithic contact at 40 to 60 inches.
Sponseller (AZ) - does not have secondary carbonate accumulation above a depth of 40 inches; does not have a calcic horizon.
Tragmon (CO) - does not have secondary carbonate accumulation above a depth of 40 inches; does not have a calcic horizon.
Trazuni (NM) - does not have horizons of secondary carbonate accunulation.
Ulrant (WY) - lithic contact at 40 to 60 inches.
Vida (MT) - does not have a calcic horizon.
Watne (MT) - depth to calcic horizon is 16 to 28 inches.
Watrous (ND) - lithic contact at depths of 20 to 40 inches.
Williams (ND) - base of the argillic horizon is deeper than 10 inches; does not have a calcic horizon.
Yegen (MT) - base of the argillic horizon is deeper than 10 inches; depth to carbonates is deeper than 20 inches.
GEOGRAPHIC SETTING:
Landform - stream terraces; alluvial fans; moraines; till plains.
Elevation - 3,400 to 6,200 feet.
Slope - 0 to 35 percent.
Parent material - alluvium; colluvium; till; glacial outwash.
Climate - cold, dry winters; moist springs; moist summers.
Mean annual precipitation - 14 to 19 inches.
Mean annual temperature - 39 to 45 degrees F.
Frost-free period - 70 to 125 days.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Fairfield soils are used mainly for irrigated and nonirrigated cropland and for range. Potential native vegetation is bluebunch wheatgrass and prairie junegrass.
DISTRIBUTION AND EXTENT: Fairfield soils are extensive mainly in the west-central part of Montana.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Reconnaissance of Northern Plains of Montana, 1929.
REMARKS: Soil interpretations records: MT0095, MT0840, MT0360. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 10 inches (Ap, Bt horizons); an argillic horizon from 6 to 10 inches (Bt horizon); accumulation of secondary carbonates from 10 to 60 inches (Bk1, Bk2, Bk3, Bk4 horizons); a particle-size control section from 6 to 40 inches (Bt, Bk1, Bk2, Bk3 and part of Bk4 horizons). Fairfield soils have a frigid temperature regime and an ustic moisture regime.
ADDITIONAL DATA: Laboratory samples S70MT-027-1, S70MT-027-2, S70MT-027-6.