LOCATION REGENT ND+MT SD
Established Series
CJH
01/2023
REGENT SERIES
The Regent series consists of moderately deep, well drained, slowly permeable soils formed in residuum weathered from alkaline soft shale, siltstone or mudstone. These soils are on uplands and have slope of 0 to 45 percent. Mean annual air temperature is 42 degrees F, and mean annual precipitations is 16 inches.
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argiustolls
TYPICAL PEDON: Regent silty clay loam - cultivated. (Colors are for dry soil unless otherwise stated)
A--0 to 10 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky and moderate fine granular structure; firm, plastic; common fine roots; common fine pores; neutral; clear smooth boundary. (5 to 10 inches thick)
Bt1--10 to 18 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure separating to strong fine angular blocky; firm, plastic; few roots; common fine pores; dark grayish brown (10YR 4/2) clay films on faces of peds; slightly alkaline; clear wavy boundary.
Bt2--18 to 26 inches; light brownish gray (2.5Y 6/2) silty clay, olive brown (2.5Y 4/3) moist; weak coarse prismatic structure separating to moderate medium subangular blocky; firm, plastic; few roots; common very fine pores; faint clay films on faces of peds; few faint white masses of carbonates; slightly alkaline; gradual wavy boundary. (Combined Bt horizons 6 to 22 inches thick)
Bk--26 to 39 inches; pale olive (5Y 6/3) silty clay loam, olive (5Y 5/3) moist; weak coarse prismatic structure separating to moderate medium subangular blocky; firm, plastic; few fine pores; common fine threads and few masses of carbonates; strongly effervescent; moderately alkaline; clear wavy boundary. (0 to 22 inches thick)
Cr--39 to 62 inches; pale olive (5Y 6/3) soft shale; moderately alkaline.
TYPE LOCATION: Stark County, North Dakota; northwest corner, sec. 3, T. 139 N., R. 97 W.
RANGE IN CHARACTERISTICS: Depth to soft shale, siltstone or mudstone bedrock ranges from 20 to 40 inches. Thickness of the mollic epipedon ranges from 7 to 16 inches. Stony phases are recognized.
The A horizon has hue of 10YR or 2.5Y, value of 4 or 5, 2 or 3 moist, and chroma of 2 or 3. It is clay loam, silty clay loam, silty clay, silt loam or cobbly loam. Reaction is slightly acid to slightly alkaline.
The Bt horizon has hue of 10YR, 2.5Y or 5Y, value of 4 to 6, 2 to 5 moist, and chroma of 2 to 4. It is silty clay loam, clay or silty clay and typically averaging between 35 and 50 percent clay. Reaction is slightly alkaline to strongly alkaline. Some pedons have a thin Bw horizon below the Bt horizon.
The Bk horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 5 to 7 and 4 to 6 moist, and chroma of 4 or less. It is silty clay loam, silty clay, clay loam or clay. It is slightly alkaline to strongly alkaline. Some pedons have a Bky, BCk or BCky horizon.
The Cr horizon is soft platy alkaline shale, siltstone or mudstone which is stratified with silty layers in some pedons. Some pedons have a C horizon above the Cr horizon.
COMPETING SERIES: These are the
Bearpaw,
Cerro,
Dutton,
Linnet,
Mondamin and
Wyola series. Bearpaw, Cerro, Linnet, Mondamin and Wyola soils do not have bedrock within depths of 40 inches. In addition, Cerro soils are stony below a depth of 26 inches and are above elevations of 6000 feet. Dutton soils occur in areas of lower precipitation.
GEOGRAPHIC SETTING: Regent soils are on level to very steep, long and plane or slightly convex slopes on uplands. The slope gradients commonly are 2 to 4 percent but range from 0 to 45 percent. The soils formed in residuum weathered from alkaline soft shale, siltstone or mudstone. Mean annual air temperature ranges from 39 to 45 degrees F, and mean annual precipitation from 13 to 18 inches. Elevation ranges from 1600 to 3600 feet above mean sea level. Average frost-free period ranges from 110 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Wyola soils and the
Grail,
Moreau,
Morton and
Rhoades soils. Wyola, Grail and Rhoades soils commonly are on lower, less sloping areas than Regent soils. In addition, Wyola soils are on terraces of nearby stream valleys and Grail soils are in concave swales and on fans. Grail soils have a mollic epipedon more than 16 inches thick and do not have paralithic beds within a depth of 40 inches. Rhoades soils have a natric horizon with strong columnar structure. Moreau soils are on steeper convex slopes. They do not have an argillic horizon. Morton soils are on nearby landscapes. They are fine-silty.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low to very high depending on slope. Permeability is slow.
USE AND VEGETATION: Cultivated areas are used for growing small grains, flax, hay and pasture. Native vegetation is mid and short grasses such as western wheatgrass, green needlegrass, blue grama and some forbs and upland sedges.
DISTRIBUTION AND EXTENT: Southwestern North Dakota, eastern Montana, northwestern South Dakota. The soil is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Salina, Kansas
SERIES ESTABLISHED: Wibaux County, Montana, 1944.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 10 inches (A horizon); argillic horizon - the zone from 10 to 26 inches (Bt1 and Bt2 horizons).
ADDITIONAL DATA: S54ND-45-3, S54ND-21-1, S58ND-13-1, S58ND-45-4, S58ND- 45-9 and S58ND-45-10 in Soil Survey Investigations Report No. 2, pages 109-203.
National Cooperative Soil Survey
U.S.A.