LOCATION SWENODA ND+MN SDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Pachic Hapludolls
TYPICAL PEDON: Swenoda fine sandy loam - in cultivation. (Colors are for moist soil unless otherwise stated)
Ap--0 to 9 inches; black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak coarse granular structure; slightly hard and very friable; slightly sticky and slightly plastic; many very fine and fine roots; neutral; clear smooth boundary.
A--9 to 13 inches; black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; moderate medium subangular blocky structure; slightly hard and very friable; slightly sticky and slightly plastic; many very fine and fine roots; neutral; clear wavy boundary. (Combined A horizons 8 to 18 inches thick)
Bw1--13 to 19 inches; very dark grayish brown (10YR 3/2) fine sandy loam, grayish brown (10YR 5/2) dry; weak coarse prismatic structure parting to moderate medium subangular blocky; slightly hard and very friable; slightly sticky and slightly plastic; common very fine and fine roots; slightly alkaline; clear wavy boundary.
Bw2--19 to 29 inches; dark yellowish brown (10YR 4/4) fine sandy loam, light yellowish brown (10YR 6/4) dry; weak coarse prismatic structure parting to moderate medium subangular blocky; slightly hard and very friable; slightly sticky and slightly plastic; few very fine and fine roots; slightly alkaline; gradual wavy boundary.
Bw3--29 to 33 inches; dark brown (10YR 4/3) fine sandy loam, pale brown (10YR 6/3) dry; weak coarse subangular blocky structure; slightly hard and very friable; slightly sticky and slightly plastic; few very fine and fine roots; about 2 percent gravel; slightly alkaline; clear wavy boundary. (Combined Bw horizons 4 to 26 inches thick)
2Bk--33 to 39 inches; grayish brown (2.5Y 5/2) loam, light gray (2.5Y 7/2) dry; common fine prominent yellowish brown (10YR 5/4) redoximorphic concentrations; weak coarse subangular blocky structure; soft and friable; slightly sticky and slightly plastic; about 4 percent gravel; violent effervescence; moderately alkaline; clear wavy boundary. (0 to 35 inches thick)
2C--39 to 60 inches; olive brown (2.5Y 4/4) loam, light yellowish brown (2.5Y 6/4) dry; common fine distinct light brownish gray (2.5Y 6/2) redoximorphic depletions and light olive brown (2.5Y 5/6) redoximorphic concentrations; massive; slightly hard and friable; slightly sticky and slightly plastic; about 4 percent gravel; slight effervescence; moderately alkaline.
TYPE LOCATION: Griggs County, North Dakota; 135 feet west and 1,750 feet south of the northeast corner of sec. 34, T. 147 N., R. 58 W.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon is greater than 16 inches. The depth to silty or loamy sediments typically is about 30 inches and ranges between 20 and 40 inches. The depth to carbonates typically is about 30 inches and ranges between 16 and 40 inches. A thin stone line is at the upper boundary of the 2Bk or 2C horizon in some pedons.
The A horizon has hue of 10YR, value of 2 or 3 and 2 to 4 dry, and chroma of 1. Chroma of 2 is allowed if it is below 7 inches or if the horizon is dry. It typically is fine sandy loam or sandy loam, but is loam or loamy fine sand in some pedons. It is slightly acid or neutral.
The Bw horizon has hue of 10YR or 2.5Y, value of 2 to 4 and 3 to 6 dry, and chroma of 1 to 4. Few to common, faint to distinct redoximorphic features are in lower parts of some pedons. The Bw horizon is fine sandy loam or sandy loam. Some pedons have thin horizons of loamy sand or loamy fine sand in the B or C horizon, but the average texture of the material between depths of 10 inches and the upper boundary of the 2C horizon is fine sandy loam or sandy loam. The Bw horizon is neutral or slightly alkaline. Some pedons have 2Bw, Bk or C horizons.
The 2Bk horizon has hue of 2.5Y or 5Y, value of 4 to 6 and 6 to 8 dry, and chroma of 2 to 6. It is silt loam or silty clay loam, or loam or clay loam till. It is slightly alkaline or moderately alkaline.
The 2C horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 6 to 8 dry, and chroma of 2 to 6. It is silt loam or silty clay loam, or loam or clay loam till. It is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Clontarf, Embden, Emrick, Flathead and Inkster None of these soils have a discontinuity of finer textured materials within 40 inches. In addition, Inkster soils have sand-sized fraction dominated by shale fragments.
GEOGRAPHIC SETTING: The Swenoda soils are nearly level to moderately sloping on uplands. The slopes are plain or convex. Slope gradients typically are less than 4 percent but range from 0 to 9 percent. The soil formed in loamy sediments overlying laminated lacustrine silt to clay or loam or clay loam till. Mean annual air temperature ranges from 36 to 48 degrees F, and mean annual precipitation ranges from 16 to 24 inches. Growing season is 120 to 130 days; average growing season precipitation ranges from 15 to 18 inches; and growing degree days are about 2500 to 3000.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Clontarf and Embden soils and the Beotia, Hamar, Hecla, Malachy, Towner, Ulen and Wyndmere soils. Beotia soils are fine-silty and are on slightly higher positions. Clontarf, Malachy and Towner soils are on similar landscapes. Malachy soils are calcareous within depths of 10 inches and do not have a discontinuity of finer textured materials within 40 inches. Towner soils have sandy particle-size in the upper control section and have contrasting textures. Embden, Ulen and Wyndmere soils are on slightly lower concave positions. The Ulen and Wyndmere soils have a calcic horizon within depths of 16 inches and have a wetter soil moisture control section. Hecla and Hamar soils are on broad flats and swales. Hamar and Hecla soils have a sandy particle-size control section and have wetter soil moisture control sections.
DRAINAGE AND PERMEABILITY: Moderately well drained or well drained. Surface runoff is low to medium. Permeability is moderately rapid in the upper part and moderate or moderately slow in the finer textured underlying material. The moderately well drained phase has a seasonal high water table at depths of 3 to 5 feet at some time during the period of April through June.
USE AND VEGETATION: When cultivated the principal crops are corn, alfalfa, small grains and tame pasture. Native grasses include big bluestem, prairie sandreed, little bluestem, needlegrass, western wheatgrass, sideoats grama, needleandthread, bluegrama, sedges and forbs.
DISTRIBUTION AND EXTENT: Northeastern South Dakota, eastern North Dakota, and western Minnesota. The series is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Marshall County, South Dakota, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 19 inches (Ap, A and Bw1 horizons); cambic horizon - the zone from 19 to 33 inches (Bw1 and Bw2 horizons).