LOCATION DEADSEA MT
Established Series
REV. KTS-RJS
01/2012
DEADSEA SERIES
The Deadsea series consists of very deep, well drained soils that formed in alluvium. These soils occur on fan remnants. These soils are subject to prolonged saturation from flood irrigation. Slopes are 1 to 4 percent. Mean annual precipitation is about 330 mm, and the mean annual air temperature is about 5 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Oxyaquic Haplustalfs
TYPICAL PEDON: Deadsea gravelly loam, in irrigated hayland on a 3 percent slope at an elevation of 1960 meters (colors are for dry soil unless otherwise noted).
Oi--0 to 5 cm; slightly decomposed matted roots; strongly acid (pH 5.5) abrupt smooth boundary. (0 to 5 cm thick)
A--5 to 18 cm; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; many fine and medium prominent strong brown (7.5YR 4/6) moist redox concentrations (due to prolonged saturation from flood irrigation); weak medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine dendritic tubular pores; 15 percent gravel and 2 percent cobbles; moderately acid (pH 6.0); clear smooth boundary. (10 to 15 cm thick)
Bt--18 to 43 cm; brown (10YR 5/3) very gravelly clay loam, brown (10YR 4/3) moist; many fine and medium distinct strong brown (7.5YR 4/6) moist redox concentrations (due to prolonged saturation from flood irrigation); moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine, fine and medium roots; common very fine and fine dendritic tubular pores; 40 percent faint clay films on all faces of peds; 30 percent gravel and 10 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (15 to 36 cm thick)
Bk1--43 to 74 cm; very pale brown (10YR 8/2) very gravelly sandy loam, pale brown (10YR 6/3) moist; weak fine and medium subangular blocky structure; soft, very friable, non-sticky and non-plastic; common very fine and fine roots; common very fine and fine irregular pores; 30 percent gravel and 10 percent cobbles; finely disseminated calcium carbonate and 50 percent distinct, irregular, calcium carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (20 to 51 cm thick)
Bk2--74 to 152 cm; very pale brown (10YR 8/2) very gravelly sandy loam, brown (10YR 5/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine and fine irregular pores; 35 percent gravel and 5 percent cobbles; finely disseminated calcium carbonate and 50 percent distinct, irregular, calcium carbonate nodules on bottom of rock fragments; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Beaverhead County, Montana; located about 2000 feet south and 1200 feet east of the northwest corner of sec. 9, T. 8 S., R 13 W; Bachelor Mountain topographic quadrangle; UTM 12T, 327053e, 4992999n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C.
Particle-size control section - 20 to 35 percent clay
Depth to calcic horizon - 25 to 60 cm
A horizon
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 or 3; dry or moist
Clay content: 18 to 25 percent
Rock fragments: 10 to 30 percent--10 to 30 percent gravel, 0 to 15 percent cobbles
Reaction: pH 5.6 to 6.5
Bt horizon
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3; dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 20 to 35 percent
Rock fragments: 35 to 65 percent--20 to 50 percent gravel, 0 to 30 percent cobbles
Reaction: pH 6.1 to 7.3
Bk horizons
Value: 6 to 8 dry; 4 to 6 moist
Chroma: 2 or 3; dry or moist
Texture: sandy loam or loam
Clay content: 8 to 18 percent
Rock Fragments: 35 to 70 percent--30 to 60 percent gravel, 0 to 30 percent cobbles
Calcium Carbonate Equivalent: 10 to 35 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - fan remnants
Elevation - 1800 to 1980 meters
Slope - 1 to 4 percent
Parent material - alluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 250 to 355 mm
Mean annual air temperature - 4 to 7 degrees F.
Frost-free period - 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Deadsea soils are used mainly for irrigated grass hay and irrigated pasture. The vegetation is mainly Garrison creeping foxtail, meadow foxtail, timothy, tufted hairgrass, Poa (species), and other miscellaneous sedges, rushes, and forbs.
DISTRIBUTION AND EXTENT: Deadsea 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, 2008.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 5 to 18 cm (A horizon)
Argillic horizon - from 18 to 43 cm (Bt horizon)
Calcic horizon - from 43 to 152 cm (Bk horizons)
Particle-size control section - from 18 to 43 cm (Bt horizon)
Deadsea soils have a frigid temperature regime, an ustic moisture regime and an oxyaquic moisture subclass.
Note: The redox concentrations and oxyaquic condition are not from a seasonally high water table, but are a result of prolonged flood irrigation. Under flood irrigation this soil is saturated with water in one or more layers within 100 cm of the mineral soil surface for more than or equal to 30 cumulative days.
National Cooperative Soil Survey
U.S.A.