LOCATION LITTLEMO NDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Aridic Haplustolls
TYPICAL PEDON: Littlemo silt loam - on a 1 percent northeast facing, plane slope in a cultivated field. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.)
Ap--0 to 6 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; neutral; abrupt smooth boundary. (4 to 9 inches)
Bw1--6 to 10 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; neutral; abrupt smooth boundary.
Bw2--10 to 17 inches; light olive brown (2.5Y 5/4) loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; neutral; clear smooth boundary. (Combined Bw horizons 5 to 16 inches thick)
Bk1--17 to 22 inches; light yellowish brown (2.5Y 6/4) loam, olive brown (2.5Y 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; violent effervescence; moderately alkaline; clear smooth boundary.
Bk2--22 to 28 inches; light gray (2.5Y 7/2) clay loam, light yellowish brown (2.5Y 6/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few fine and medium irregularly shaped masses of carbonates; violent effervescence; moderately alkaline; clear wavy boundary. (Combined Bk horizons 0 to 20 inches thick)
2C1--28 to 34 inches; pale yellow (2.5Y 8/2) gravelly sandy clay loam, pale yellow (2.5Y 7/4) moist; single grain; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; about 15 percent gravel; few fine irregularly shaped masses of carbonates on undersides of pebbles; violent effervescence; moderately alkaline; clear wavy boundary.
2C2--34 to 60 inches; light yellowish brown (2.5Y 6/4) very gravelly coarse sandy loam, olive brown (2.5Y 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; about 40 percent gravel; strong effervescence; moderately alkaline.
TYPE LOCATION: Billings County, North Dakota; 2,500 feet south and 200 feet east of the northwest corner, sec. 33, T. 138 N., R. 102 W.
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 11 to 24 inches. The thickness of the mollic epipedon ranges from 7 to 16 inches. The depth to horizons with greater than 35 percent rock fragments commonly is between 25 to 38 inches, but ranges from 20 to 40 inches.
The A horizon has hue of 10YR, value of 4 or 5 and 2 or 3 moist, and chroma of 2 or 3. It is silt loam or loam and is medium acid to slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 2 to 4 moist, and chroma of 2 or 4. It is silt loam or loam and is slightly acid to moderately alkaline.
The Bk horizon has hue of 10YR or 2.5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It is loam, silt loam or clay loam and is slightly alkaline to strongly alkaline. The calcium carbonate equivalent is 15 to 35 percent. Some pedons have 2Bk or 2BCk horizons.
The 2C horizon has hue of 10YR or 2.5Y, value of 5 to 8 and 3 to 7 moist, and chroma of 2 to 4. It is sandy clay loam, coarse sandy loam, loam or sandy loam containing 15 to 70 percent rock fragments. It is slightly alkaline to strongly alkaline. Textures of loamy coarse sand and loamy sand are below depths of 40 inches in some pedons.
COMPETING SERIES: These are the Anamac, Boxwell, Conn, Fortbenton, Kremlin and Waterhill series. Boxwell soils have soft bedrock at depths of 20 to 40 inches. Anamac, Con, Fortbenton and Kremlin soils have less than 35 percent rock fragments throughout and do not have a discontinuity.
GEOGRAPHIC SETTING: Littlemo soils are on level to moderately sloping fans and high terraces of the Little Missouri River. The soils are on plane or slightly concave positions. Slopes typically are less than 4 percent, but range from 0 to 9 percent. The soil formed in loamy alluvium underlain by stratified loamy sediments containing appreciable amounts of gravel. Mean annual temperature ranges from 39 to 45 degrees F and the mean annual precipitation from 13 to 16 inches. Most of the precipitation falls in the spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: There are the competing Kremlin soils and the Boxwell, Cabbart, Chanta, Lonna, Rhame, Subwell, and Tinsley soils. Chanta, Kremlin, and Subwell soils are on similar landscapes. Chanta soils are fine-loamy over sandy or sandy-skeletal. Subwell soils are loamy-skeletal. Boxwell and Rhame are on adjacent side slopes. They have a paralithic contact at depths of 20 to 40 inches. Cabbart and Tinsley soils are on crests of hills and steep slopes on uplands. Cabbart soils have a paralithic contact at depths of less than 20 inches. Tinsley soils have sand and gravel at depths of 7 to 14 inches. Lonna soils are on fans or foot slopes. They do not have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderate in the upper part and moderately rapid or rapid in the lower part.
USE AND VEGETATION: Used mainly for small grains, hay and pasture. Native vegetation is western wheatgrass, needleandthread and blue grama.
DISTRIBUTION AND EXTENT: Eastern Montana and southwestern North Dakota. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Billings County, North Dakota, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - zone from the surface of the soil to a depth of 10 inches (A and Bw1 horizons); cambic horizon - zone from 10 to 17 inches (Bw2 horizon); calcic horizon zone from 17 to 28 inches (Bk1 and Bk2 horizons).
ADDITIONAL DATA: NSSL laboratory data pedon numbers S89ND007-1 and S89ND007-2 (Typical Pedon).