LOCATION SAPPINGTON MT

Established Series
Rev. JB-JJU-RJS
06/2011

SAPPINGTON SERIES

The Sappington series consists of very deep, well drained soils that formed in calcareous alluvium, slope alluvium, colluvium or outwash. These soils are on stream terraces, alluvial fans, fan remnants, knolls, outwash plains and hills. Slopes are 0 to 25 percent. Mean annual precipitation is about 11 inches, and mean annual air temperatures is about 43 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Calcidic Argiustolls

TYPICAL PEDON: Sappington loam, cultivated (colors are for dry soil unless otherwise noted).

Ap--0 to 4 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; 1 percent gravel; slightly alkaline (pH 7.6); abrupt smooth boundary. (4 to 6 inches thick)

Bt--4 to 6 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate fine angular blocky; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine tubular and interstitial pores; continuous faint clay films on faces of peds; 1 percent gravel; slightly alkaline (pH 7.5); abrupt smooth boundary. (2 to 4 inches thick)

Btk--6 to 9 inches; pale brown (10YR 6/3) loam, brown (10YR 5/3) moist; moderate medium prismatic structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and fine tubular and interstitial pores; few faint clay films on faces of peds; 1 percent gravel; common distinct coatings of white calcium carbonate on faces of peds; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 5 inches thick)

Bk1--9 to 20 inches; very pale brown (10YR 8/2) loam, very pale brown (10YR 7/3) moist; weak coarse prismatic structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and fine tubular and interstitial pores; 1 percent gravel; many distinct coatings of calcium carbonate on faces of peds; violently effervescent; moderately alkaline (pH 8.3); gradual smooth boundary. (7 to 15 inches thick)

Bk2--20 to 34 inches; very pale brown (10YR 8/3) loam, pale brown (10YR 6/3) moist; weak coarse angular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular and interstitial pores; 2 percent gravel; finely disseminated calcium carbonate, few fine masses of calcium carbonate, and few distinct coatings of calcium carbonate on faces of peds; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (8 to 20 inches thick)

Bk3--34 to 72 inches; very pale brown (10YR 7/3) loam, brown (10YR 5/3) moist; massive; hard, very friable, slightly sticky and slightly plastic; few fine roots; few very fine and fine tubular and interstitial pores; 2 percent gravel; finely disseminated calcium carbonate and few fine masses of calcium carbonate; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Lewis and Clark County, Montana; 50 feet north and 2,560 feet east of the southwest corner of sec. 27, T. 10N, R. 2W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 40 to 47 degrees F.
Mollic epipedon thickness - 7 to 9 inches and includes part of the Bt horizon
Depth to base of argillic horizon - less than 10 inches
Depth to calcic horizon - 7 to 10 inches

Ap horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry
Chroma: 2 or 3; dry or moist
Texture: loam, clay loam, sandy clay loam or sandy loam
Clay content: 15 to 35 percent
Rock fragments: 0 to 35 percent--0 to 25 percent gravel, 0 to 10 percent cobbles
Reaction: pH 6.6 to 7.8

Bt horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4; dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 25 percent gravel
Reaction: pH 6.6 to 7.8

Btk horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam or sandy loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 25 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.4 to 8.4

Bk1, Bk2 horizons
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 2 to 4; dry or moist
Texture: loam or sandy loam
Clay content: 5 to 27 percent (10 to 18 percent noncarbonate clay)
Rock fragments: 0 to 25 percent gravel
Calcium carbonate equivalent: 15 to 40 percent
Reaction: pH 7.9 to 8.4

Bk3 horizon
Hue: 7.5YR, 10YR or 2.5Y; dry or moist
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 to 4; dry or moist
Texture: loam or sandy loam
Clay content: 10 to 27 percent (10 to 18 percent noncarbonate clay)
Rock fragments: 0 to 25 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - stream terraces, alluvial fans, fan remnants, knolls, outwash plains and hills
Elevation - 3,500 to 6,500 feet
Slope - 0 to 25 percent
Parent material - calcareous alluvium, slope alluvium, colluvium or outwash
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 10 to 14 inches
Mean annual temperature - 38 to 45 degrees F.
Frost-free period - 70 to 120 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amesha, Crago, and Musselshell soils. These soils do not have mollic epipedons or argillic horizons. They are on similar landform positions.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: Sappington soils are used mainly for rangeland and cropland. Potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, Sandberg bluegrass, prairie junegrass, needleandthread, green needlegrass, forbs, and shrubs.

DISTRIBUTION AND EXTENT: Sappington soils are moderately extensive in central and southwestern Montana. MLRAs - 43B, 44B.

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

SERIES ESTABLISHED: Broadwater County area, Montana, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 7 inches, mixed (A, Bt, part of Btk horizons)
Argillic horizon - from 4 to 9 inches (Bt, Btk horizons)
Secondary calcium carbonate accumulation - from 6 to 72 inches (Btk, Bk1, Bk2, Bk3 horizons)
Calcic horizon - from 9 to 34 inches (Bk1, Bk2 horizons)
Particle-size control section - from 4 to 40 inches (Bt, Btk, Bk1, Bk2, and part of the Bk3 horizons)

Sappington soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.

ADDITIONAL DATA: Laboratory data - S70MT-049-2, S70MT-409-3; Soil interpretations records - MT0382 and MT0679.

National Cooperative Soil Survey
U.S.A.