LOCATION AMOR ND+MT SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Amor loam - on a 3 percent south-facing plane slope in a cultivated field. When described the soil was moist below 8 inches. (Colors are for dry soil unless otherwise stated)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) loam; very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to weak medium and fine granular; slightly hard, friable, slightly sticky and nonplastic; many roots and pores; neutral; abrupt smooth boundary. (5 to 9 inches thick)
Bw1--8 to 13 inches; brown (10YR 5/3) loam; dark brown (10YR 3/3) moist; a few stains of dark grayish brown (10YR 4/2) on faces of peds; weak coarse prismatic structure parting to weak coarse and medium subangular blocky; hard, friable, slightly sticky and slightly plastic; common roots; many fine pores; neutral; gradual wavy boundary.
Bw2--13 to 19 inches; light brownish gray (2.5Y 6/2) loam; dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable, slightly sticky and slightly plastic; common fine roots; common fine pores; slight effervescence; slightly alkaline; gradual wavy boundary. (Combined Bw horizons 4 to 27 inches thick)
Bk--19 to 31 inches; light gray (2.5Y 7/2) loam; grayish brown (2.5Y 5/2) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few fine roots; common fine pores; few masses of carbonates; violent effervescence; moderately alkaline; gradual wavy boundary. (0 to 21 inches thick)
Cr--31 to 60 inches; pale yellow (2.5Y 7/3) and light gray (5Y 7/2) soft sandstone and siltstone; light olive gray (5Y 6/2) and light olive brown (2.5Y 5/3) moist; slight effervescence; moderately alkaline.
TYPE LOCATION: Bowman County, North Dakota; 6 1/2 miles west and 1 mile north of Bowman; 2,300 feet east and 180 feet north of the southwest corner, sec. 2, T. 131 N., R. 103 W.
RANGE IN CHARACTERISTICS: Depth to soft sandstone typically is 30 to 40 inches but ranges from 20 to 40 inches. Depth to carbonates ranges from 10 to 40 inches. The 10- to 40-inch control section averages 15 to 40 percent fine sand and coarser. Stony phases are recognized.
The A horizon has hue of 10YR, value of 3 to 5 and 2 or 3 moist, and chroma of 2 or 3. It is loam, silt loam or clay loam. Some pedons contain up to 15 percent rock fragments. It is slightly acid to slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 7 and 3 to 6 moist, and chroma of 2 to 4. It is sandy clay loam, fine sandy loam, loam or clay loam. It has weak or moderate prismatic structure. It is neutral to moderately alkaline. It is non-effervescent to slightly effervescent.
The Bk horizon has hue of 10YR or 2.5Y, value of 5 to 8 and 4 to 6 moist, and chroma of 2 to 4. It is loam, silt loam, fine sandy loam or clay loam. It is slightly alkaline or moderately alkaline. It contains from 5 to 30 percent calcium carbonate equivalent. Carbonates are both disseminated and in masses. Some pedons have a BCk horizon with similar properties.
Some pedons have a C horizon. It has hue of 2.5Y, value of 6 or 7 and 4 to 6 moist, and chroma of 2 or 3. It is loam. It is slightly alkaline or moderately alkaline.
The Cr horizon is stratified soft fine grained sandstone, siltstone, and mudstone. Some pedons have carbonate accumulations below the top of the bedrock.
COMPETING SERIES: These are the Azaar, Diagulch, Max, Peerless, Quigley, Shambo, Tansem, Tewfel and Twin Creek series. Azaar soils have indurated sandstone bedrock within depths of 20 to 40 inches. Diagulch, Max, Peerless, Quigley, Shambo, Tansem and Twin Creek soils do not have paralithic beds within depths of 20 to 40 inches. Tewfel soils have paralithic beds of shale within depths of 20 to 40 inches and have a frost-free period of less than 90 days.
GEOGRAPHIC SETTING: Amor soils are on level to moderately steep uplands. Slope gradients typically range from 0 to 10 percent, but some are as steep as 25 percent. The soils formed in residuum weathered from stratified soft sandstone, siltstone and mudstone. Mean annual air temperature ranges from 39 to 45 degrees F, and precipitation ranges from 13 to 18 inches. Precipitation comes in the spring and summer. It ranges up to 20 inches in the foothills of the mountains. The frost-free season ranges from 110 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Shambo soils and the Arnegard, Cabba, Flasher, Reeder and Vebar soils. Shambo soils are on terraces and nearly level areas. Arnegard soils are in concave swales and on foot slopes. They do not have paralithic beds within a depth of 40 inches and have a mollic epipedon more than 16 inches thick. Cabba and Flasher soils are on adjacent steeply sloping uplands. They have paralithic beds at depths of less than 20 inches. Reeder soils are on less sloping upland areas adjacent to the Amor soils. They have argillic horizons. Vebar soils are on adjacent uplands. They are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained. Runoff ranges from negligible to high depending on the slope. Permeability is moderate.
USE AND VEGETATION: Commonly cropped to small grains, flax, corn, hay and grass in a crop summer fallow rotation. Native vegetation is mid and short prairie grasses such as green needlegrass, needleandthread, western wheatgrass and blue grama.
DISTRIBUTION AND EXTENT: Southwestern North Dakota, northwestern South Dakota, and eastern Montana. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Bowman County, North Dakota, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - zone from the surface of the soil to a depth of 13 inches (Ap and Bw1 horizons); cambic horizons - zone from 13 to 19 inches (Bw2 horizon).