LOCATION TOBY NDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aridic Haplustepts
TYPICAL PEDON: Toby fine sandy loam - on a 2 percent slope in a cultivated field. (Colors are for dry soil unless otherwise stated)
Ap--0 to 8 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium and fine subangular blocky and weak fine granular structure; slightly hard, very friable, slightly sticky and nonplastic; many fine roots; many fine pores; neutral; abrupt smooth boundary. (6 to 10 inches thick)
Bw1--8 to 22 inches; brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; weak coarse prismatic structure parting to weak coarse subangular blocky; slightly hard, very friable, slightly sticky and nonplastic; common fine roots; common fine pores; neutral; gradual wavy boundary.
Bw2--22 to 38 inches; light olive brown (2.5Y 5/4) fine sandy loam, olive brown (2.5Y 4/4) moist; weak coarse prismatic structure parting to weak coarse subangular blocky; slightly hard, very friable, slightly sticky and nonplastic; common fine roots; common fine pores; slightly alkaline; gradual wavy boundary. (Combined Bw horizons 21 to 40 inches thick)
C--38 to 60 inches; grayish brown (2.5Y 5/2) fine sandy loam, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few fine roots; few fine pores; slight effervescence; moderately alkaline.
TYPE LOCATION: Bowman County, North Dakota; 2,600 feet west and 2,530 feet south of the north east corner, sec. 11, T. 130 N., R. 106 W.
RANGE IN CHARACTERISTICS: The depth to the base of the cambic and depth to carbonates ranges from 30 to 45 inches. The soil has 0 to 5 percent rock fragments.
The A horizon has hue of 10YR, value of 5 or 6 and 3 or 4 moist, and chroma of 2 or 3. It is fine sandy loam, sandy loam or loam. It is neutral or slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 5 or 6 and 4 or 5 moist, and chroma of 2 to 4. It is fine sandy loam or sandy loam. It is neutral to moderately alkaline.
The C horizon is fine sandy loam, loam, sandy loam or loamy fine sand. It is neutral to moderately alkaline.
COMPETING SERIES: These are the Spang soils. Spang soils have hue redder than 10YR throughout and formed in alluvium from porcelanite.
GEOGRAPHIC SETTING: The level to strongly sloping Toby soils are on fans, terraces, hills and ridges. The slope ranges from 0 to 15 percent. The soils formed in alluvium and eolian deposits. The mean annual air temperature varies from 40 to 46 degrees F, and the mean annual precipitation varies from 11 to 16 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fleak, Havre, Kremlin, Rhame and Zeona soils. Fleak soils are shallow to soft sandstone and are on side slopes and ridges higher in the landscape. Havre soils are fine-loamy and are on adjacent flood plains and lower terraces. Kremlin soils are fine-loamy and have a mollic epipedon. They are on toe slopes. Rhame soils are moderately deep to bedded sandstone and less than 30 inches to carbonates and the base of the cambic horizon. The Rhame soils are on higher slopes than the Toby soils. Zeona soils are sandy. They are on ridges, hummocks and dunes.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium. Permeability is moderately rapid.
USE AND VEGETATION: These soils are used for crops, hay, and pasture. Native grasses include blue grama, needleandthread, prairie sandreed, and western wheatgrass.
DISTRIBUTION AND EXTENT: Toby soils are of small extent in southwestern North Dakota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Hill County, Montana, 1963.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 8 inches (Ap horizon); cambic horizon - the zone from 8 to 38 inches (Bw1 and Bw2 horizons); greater than 0.15 percent organic carbon in the upper 16 inches (Ap and Bw1 horizons).