LOCATION TOREX MTEstablished Series
TAXONOMIC CLASS: Sandy over loamy, mixed, superactive, frigid Entic Haplustolls
TYPICAL PEDON: Torex loamy sand, cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 8 inches, dark grayish brown (10YR 4/2) loamy sand, very dark brown (10YR 2/2) moist; very weak subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many fine and very fine roots; slightly alkaline (pH 7.6); clear wavy boundary. (5 to 8 inches thick)
A1--8 to 17 inches, dark grayish brown (10YR 4/2) loamy sand, very dark brown (10YR 2/2) moist; weak coarse prismatic structure; slightly hard, very friable, nonsticky and nonplastic; many fine and very fine pores: few medium pores; common fine and very fine roots; few pebbles; slightly alkaline (pH 7.6); clear wavy boundary. (8 to 12 inches thick)
A2--17 to 24 inches, grayish brown (10YR 5/2) loamy sand, dark grayish brown (10YR 4/2) moist; very weak, very coarse prismatic structure; soft, very friable, nonsticky and nonplastic; many fine and very fine pores and few medium pores; common fine and very fine roots; slightly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (7 to 12 inches thick)
2C--24 to 60 inches, light gray (2.5Y 7/2) very fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; many fine and very fine pores and few medium pores; many fine threads and fine masses of lime; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Cascade County, Montana; 1,800 feet east and 1,200 feet south of the NW corner of section 28, T.19N., R.2E.
RANGE IN CHARACTERISTICS: The depth to the underlying contrasting texture is 20 to 40 inches. The mollic epipedon is 12 to 20 inches thick. The hue is 10YR or 2.5Y throughout the soil. The mean annual soil temperature ranges from 42 to 47 degrees F.
The Ap, A1, and A2 horizons have value of 3 or 4 dry, 2 or 3 moist, and chroma of 2 or 3. They are loamy fine sand, fine sand, or loamy sand. Reaction is neutral or slightly alkaline.
The A2 horizon is lacking in some pedons and is replaced by a C or Cca horizon. These horizons have value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 or 3. They are slightly or moderately alkaline. Texture is loamy sand, loamy fine sand, or fine sand.
The underlying contrasting 2C horizon has value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 or 3. It is silt loam, very fine sandy loam, or loam, and has 20 to 35 percent clay.
Some pedons have a very gravelly loamy sand 3C horizon below depths of 50 inches.
COMPETING SERIES: This is the Ervide series. Ervide soils have sandstone below the 2C horizons at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Torex soils are undulating to strongly rolling, and are on terraces and uplands at elevations of 2,000 to 4,000 feet. The soils formed in sandy alluvium deposited over very fine sandy loam or silt loam sediments or clay loam till. Average annual precipitation is 14 to 19 inches. Mean annual temperature is 42 to 45 degrees F.; mean January temperature is 20 to 25 degrees F.; and mean July temperature is 65 to 70 degrees F. The frost-free period is 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ervide soils and the Lihen, Yetull and Tally soils. Lihen soils have sandy control sections. Yetull soils have ochric epipedons. Tally soils have coarse-loamy control sections.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; permeability is rapid in the A horizons and is moderate in the IIC horizons.
USE AND VEGETATION: Torex soils are used for dry-farmed cropland and for rangeland. Wheat, barley, and grass-legume hay and pasture are the main crops. Native vegetation is prairie sandreed, little bluestem, sand dropseed, needle-and-thread grass, Indian ricegrass, prairie junegrass, and yucca.
DISTRIBUTION AND EXTENT: Central and northern Montana. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Cascade County, Montana, 1975.