LOCATION MAGPIE MT
Established Series
KTS-RJS
01/2012
MAGPIE SERIES
The Magpie series consists of very deep, somewhat poorly drained soils that formed in alluvium. These soils occur on stream terraces, fan remnants and drainageways. Slopes are 0 to 4 percent. Mean annual precipitation is about 300 mm, and the mean annual air temperature is about 5 degrees C.
TAXONOMIC CLASS: Clayey over sandy or sandy-skeletal, smectitic over mixed, frigid Typic Natrustalfs
TYPICAL PEDON: Magpie loam, in irrigated pasture (colors are for dry soil unless otherwise noted).
Oi--0 to 4 cm; slightly decomposed matted roots; abrupt smooth boundary. (0 to 8 cm thick)
E--4 to 11 cm; gray (10YR 6/1) loam, very dark gray (10YR 3/1) moist; moderate very coarse platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots throughout; many very fine irregular pores throughout; finely disseminated calcium carbonate; very slightly effervescent; strongly alkaline (pH 9.0); abrupt smooth boundary. (6 to 15 cm thick)
Btn--11 to 31 cm; grayish brown (10YR 5/2), clay, very dark grayish brown (10YR 3/2) moist; strong coarse columnar structure; extremely hard, very firm, very sticky and very plastic; many very fine and fine roots throughout; common very fine dendritic tubular pores throughout; many prominent clay films on faces of peds; finely disseminated calcium carbonate throughout; slightly effervescent; very strongly alkaline (pH 9.4); gradual wavy boundary. (8 to 33 cm thick)
Btkn1--31 to 42 cm; light brownish gray (10YR 6/2), clay loam, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common very fine and fine roots throughout; common very fine and fine dendritic tubular pores throughout; many distinct clay films on faces of peds; finely disseminated calcium carbonate and many fine and medium irregular soft masses of calcium carbonate throughout; strongly effervescent; very strongly alkaline (pH 9.6); gradual wavy boundary.
Btkn2--42 to 54 cm; pale brown (10YR 6/3) clay loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine and fine roots throughout; common very fine and fine dendritic tubular pores throughout; many distinct clay films on faces of peds; 5 percent gravel and 5 percent cobbles; finely disseminated calcium carbonate and many fine and medium patchy soft masses and threads of calcium carbonate throughout; effervescent; very strongly alkaline (pH 9.6); clear wavy boundary. (combined thickness of Btkn1, Btkn2 horizons - 20 to 75 cm)
2C--54 to 152 cm; white (10YR 8/1) extremely gravelly sand, light brownish gray (10YR 6/2) moist; single grain; loose, nonsticky and nonplastic; 55 percent gravel and 10 percent cobbles; finely disseminated calcium carbonate; slightly effervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Beaverhead County, Montana; Coyote Creek topographic quadrangle; UTM 12T, 320785e, 4987743n; 1200 feet north and 100 feet west of the SE corner of sec.25, T. 9S, R. 14W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 7 degrees C.
Depth to seasonal high water table - 60 to 100 cm
Depth to top of natric horizon - 5 to 20 cm
Depth to secondary calcium carbonate accumulation - 28 to 41 cm
Depth to lithologic discontinuity - 50 to 100 cm
Note: Some pedons have an A horizon (5 to 8 cm thick) above the E horizon.
E horizon
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1 or 2; dry or moist
Clay content: 16 to 26 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Sodium adsorption ratio: 13 to 40
Electrical conductivity: 4 to 16 mmhos/cm
Reaction: pH 8.5 to 9.0
Btn horizon
Value: 5 or 6 dry; 3 to 5 moist
Chroma: 2 or 3; dry or moist
Texture: silty clay loam, clay loam, silty clay or clay
Clay content: 35 to 55 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 1 to 10 percent
Sodium adsorption ratio: 13 to 100
Electrical conductivity: 8 to 24 mmhos/cm
Reaction: pH 8.5 to 10.0
Btkn horizons
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: clay loam, sandy clay loam or silty clay loam
Clay content: 27 to 40
Rock fragments: 0 to 25 percent--0 to 25 percent gravel, 0 to 10 percent cobbles
Calcium carbonate equivalent: 5 to 15 percent
Sodium adsorption ratio: 13 to 100
Electrical conductivity: 8 to 24 mmhos/cm
Reaction: pH 8.5 to 10.0
2C horizon
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 2 or 3; dry or moist
Texture: sand or loamy sand
Clay content: 0 to 10 percent
Rock Fragments: 45 to 70 percent--45 to 70 percent gravel, 0 to 30 percent cobbles
Calcium carbonate equivalent: 0 to 5 percent
Sodium adsorption ratio: 0 to 13
Electrical conductivity: 0 to 4 mmhos/cm
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - stream terraces, fan remnants and drainageways
Elevation - 1775 to 1985 meters
Slope - 0 to 4 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; warm short summers
Mean annual precipitation - 230 to 360 mm.
Mean annual air temperature - 4 to 7 degrees C.
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow over very rapid permeability.
USE AND VEGETATION: Magpie soils are used mainly for irrigated and non-irrigated pasture. Potential native vegetation is mainly big sagebrush, basin wildrye, inland saltgrass, foxtail barley, thickspike wheatgrass, greasewood, POA (species), and other grasses and forbs.
DISTRIBUTION AND EXTENT: Magpie soils are of small extent in southwestern Montana. MLRA - 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Horse Prairie-South Valley Area - Part of Beaverhead County, Montana, 2011; proposed in Beaverhead County, Montana, 2007.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - from 0 to 11 cm (E horizon)
Natric horizon - from 11 to 54 cm (Btn, Btkn1, Btkn2 horizons)
Secondary calcium carbonate accumulation - from 31 to 54 cm (Btkn1, Btkn2)
Lithologic discontinuity - at 54 cm (2C horizon)
Particle-size control section from 11 to 100 cm (Btn, Btkn1, Btkn2 and part of the 2C horizons)
Magpie soils have a frigid temperature regime, an ustic moisture regime and an oxyaquic moisture subclass.
National Cooperative Soil Survey
U.S.A.