LOCATION LOSTRIVER MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Aridic Ustifluvents
TYPICAL PEDON: Lostriver clay, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 3 inches; light brownish gray (2.5Y 6/2) clay, dark grayish brown (2.5Y 4/2) moist; weak very fine granular structure; extremely hard, extremely firm, very sticky and very plastic; common very fine roots; many very fine pores; strongly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (2 to 6 inches thick)
C--3 to 9 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; massive; extremely hard, extremely firm, very sticky and very plastic; common very fine roots; common very fine pores; strongly effervescent; very strongly alkaline (pH 9.4); abrupt wavy boundary. (0 to 15 inches thick)
Cyz--9 to 60 inches; grayish brown (2.5Y 5/2) clay consisting of clay with thin strata of silty clay loam and clay loam, dark grayish brown (2.5Y 4/2) moist; massive; extremely hard, extremely firm, very sticky and very plastic; few very fine roots; common very fine pores; common fine masses of gypsum and other salts; strongly effervescent; very strongly alkaline (pH 9.4).
TYPE LOCATION: Hill County, Montana; 800 feet north and 800 feet east of the SW corner of sec. 3, T. 35 N., R. 12 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Soil moisture control section - between 4 and 12 inches, dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at 20 inches is 41 degrees F or above.
A horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5, or 6 dry; 3, 4, or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, clay, or silty clay
Clay content: 27 to 55 percent clay
Electrical conductivity: 2 to 8 mmhos/cm
Sodium adsorption ratio: 8 to 13
Reaction: pH 7.4 to 9.4
Calcium carbonate equivalent: 0 to 10
Some pedons have an Ayz horizon.
C horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam; clay or silty clay with or without thin strata of loam, clay loam, or silty clay loam
Clay content: 35 to 55 percent clay
Electrical conductivity: 4 to 16 mmhos/cm
Sodium adsorption ratio: 13 to 20
Reaction: pH 7.4 to 9.6
Calcium carbonate equivalent: 5 to 10
Cyz horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6, or 7 dry; 3, 4, 5, or 6 moist
Chroma: 2, 3, or 4
Texture: clay loam, silty clay loam; clay or silty clay with or without thin strata of loam, clay loam, or silty clay loam
Clay content: 35 to 55 percent clay
Electrical conductivity: 8 to 16 mmhos/cm
Sodium adsorption ratio: 13 to 30
Gypsum: 2 to 5 percent
Reaction: pH 7.4 to 9.6
Calcium carbonate equivalent: 5 to 10
Gypsum and other salts are inherent in the parent material. Some profiles have thin strata of sandy material below 40 inches.
COMPETING SERIES:
Harlake (MT) - has an SAR of less than 13 and EC less than 8 mmhos/cm below the Ap horizon.
GEOGRAPHIC SETTING:
Landform - flood plains.
Elevation - 2,000 to 2,800 feet.
Slopes- 0 to 2 percent.
Parent material - alluvium.
Climate - long, cold winters; moist springs; hot, dry summers.
Mean annual precipitation - 10 to 14 inches, most of which falls during spring and early summer.
Mean annual air temperature - 40 to 45 degrees F.
Frost-free period - 100 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability. Runoff is low or medium depending on slope.
USE AND VEGETATION: Lostriver soils are used mainly as rangeland. Few areas are used for nonirrigated cropland. The potential plant community is western wheatgrass, inland saltgrass, alkali sacaton, greasewood, and gardner saltbush.
DISTRIBUTION AND EXTENT: Lostriver soils are of moderate extent in Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Hill County, Montana, 1994.
REMARKS: Soil interpretation record: MT1352. Diagnostic horizon and features recognized in this pedon: an ochric epipedon from 0 to 7 inches mixed (A, C horizons); a particle size control section from 10 to 40 inches. Lostriver soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.
ADDITIONAL DATA: Laboratory data--S91MT-041-1.