LOCATION PLAYMOOR SD+NDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, frigid Cumulic Endoaquolls
TYPICAL PEDON: Playmoor silty clay loam - on flood plain of Whetstone River under native grass. When described the soil was wet to 60 inches. (Colors are for moist soil unless otherwise stated.)
Az--0 to 6 inches; black (5Y 2/1) silty clay loam, dark gray (5Y 4/1) dry; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine accumulations of salt; strong effervescence; slightly alkaline; clear wavy boundary. (6 to 22 inches thick)
Bz--6 to 16 inches; very dark gray (5Y 3/1) silty clay loam, gray (N 5/0) dry; weak medium and coarse subangular blocky structure parting to weak fine and medium granular; slightly hard, friable, slightly sticky and slightly plastic; many fine accumulations of salt; common fine nests of gypsum; strong effervescence; slightly alkaline; abrupt wavy boundary. (0 to 24 inches thick)
Bkz--16 to 23 inches; black (5Y 2/1) silty clay loam, dark gray (N 4/0) dry; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine accumulations of salt; few medium accumulations of carbonate; strong effervescence; slightly alkaline; clear wavy boundary.
Bk--23 to 38 inches; very dark gray (5Y 3/1) silty clay loam, gray (N 5/1) dry; few fine faint very dark grayish brown (10YR 3/2) redox concentrations; weak coarse subangular blocky structure; hard, friable, sticky and slightly plastic; few fine and medium accumulations of carbonate; strong effervescence; slightly alkaline; clear wavy boundary. (Combined Bk horizons are 0 to 32 inches thick.)
Cg--38 to 60 inches; gray (5Y 5/1) silty clay loam, light gray (5Y 6/1) dry; many fine distinct very dark grayish brown (10YR 3/2) and few medium distinct yellowish brown (10YR 5/6) redox concentrations; massive; hard, firm, sticky and plastic; few fine and medium accumulations of carbonate; strong effervescence; slightly alkaline.
TYPE LOCATION: Roberts County, South Dakota; about one-third mile north of Wilmot; 2212 feet east and 1760 feet north of the southwest corner of sec. 31, T. 123 N., R. 49 W.
RANGE IN CHARACTERISTICS: The 10 to 40 inch particle size control section typically is silty clay loam, but silt loam is within the range averaging between 20 and 35 percent noncarbonate clay. Some pedons have thin layers within the control section containing more than 35 percent clay. The mollic epipedon ranges from 24 to more than 60 inches in thickness. The electrical conductivity ranges from 4 to 16 mmho/cm in the upper 20 inches of the profile. Exchangeable sodium percentage ranges from about 8 to 16 percent. Reaction is slightly alkaline to strongly alkaline throughout. Buried A horizons are common. The A horizon and control section contain carbonate.
The A horizon has hue of 10YR, 2.5Y, 5Y, or neutral; value of 2 or 3 and 3 to 5 dry; and chroma of 1 or less. It is silty clay loam or silt loam. Fine accumulations of salt range from few to many in the A horizon.
The Bz horizon has hue of 10YR, 2.5Y, 5Y, or neutral; value of 2 to 4 and 3 to 7 dry; and chroma of 1 or less. It is silty clay loam or silt loam. Accumulations of salts, carbonate, and gypsum are few to many. Some pedons have a BC horizon with colors of the Bz horizon. Some pedons do not have Bz horizons.
The Bk horizon has hue of 2.5Y, 5Y, or neutral; value of 2 to 6 and 4 to 7 dry; and chroma of 0 or 1. It is silty clay loam or silt loam. Some pedons have a Bg horizon with colors of the Bk horizon.
The Cg horizon has hue of 2.5Y or 5Y, value of 3 to 6 and 5 to 7 dry, and chroma of 0 to 2. Glacial till or thin strata of sand, silt or clay are below a depth of 40 inches in some pedons. Some pedons have a Cyg horizon.
COMPETING SERIES: These are the Downata, Halleck, Inkom, Lamoure, and Rauville series. Downata, Halleck, and Inkom soils do not have electrical conductivities greater than 4 in the upper 20 inches of the control section. The Lamoure and Rauville soils contain less visible salt throughout the profile and contain less than 8 percent exchangeable sodium.
GEOGRAPHIC SETTING: The Playmoor soils are on nearly level flood plains and broad flats. Slope gradients are less than 2 percent. They formed in silty and clayey alluvial sediments and have high water tables. Mean annual air temperature ranges from 36 to 48 degrees F., and mean annual precipitation from 17 to 24 inches. Growing season is about 120 to 130 days; average growing season precipitation ranges from 14 to 18 inches; and growing degree days are about 2500 to 3000.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lamoure soils and the Dovray, Forman, LaDelle, Ludden, Peever, and Poinsett soils. The Lamoure and Ludden soils are in similar landscapes. Dovray soils are deeper to carbonate, have a fine textured series control section, and are on similar landscapes. The Forman, Peever, and Poinsett soils do not have redox features with chroma of 2 or less within depths of 40 inches and are on adjacent uplands. In addition, the Forman and Peever soils have argillic horizons. LaDelle soils are moderately well drained and do not have concentrations of salt in the upper part of the profile, and are on slightly higher positions on the landscape. Ludden soils have a fine textured series control section.
DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is negligible or low. Permeability is moderate or moderately slow. The water table is near the surface in the spring and at depths of 20 to 40 inches in the fall. The soils flood for short periods when streams overflow.
USE AND VEGETATION: Mostly used as pasture or hayland. Some areas are used to grow corn, small grains, and feed crops. Native vegetation is nuttall alkaligrass, switchgrass, cordgrass, foxtail barley, western wheatgrass, sedges, and forbs.
DISTRIBUTION AND EXTENT: Northeastern South Dakota and adjacent parts of North Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Marshall County, South Dakota, 1970.
REMARKS: The Playmoor soils have 15 to 20 percent calcium carbonate equivalent at depths greater than 16 inches.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 38 inches (Az, Bz, Bkz, Bk horizons).