LOCATION LUDDEN ND+MN SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Endoaquerts
TYPICAL PEDON: Ludden clay - in a level cultivated field. (Colors are for moist soil unless otherwise stated)
Ap--0 to 5 inches; black (10YR 2/1) clay, dark gray (N 4/0) dry; moderate medium subangular blocky structure parting to moderate very fine angular blocky; extremely hard, firm, sticky and very plastic; slight effervescence; slightly alkaline; abrupt smooth boundary.
A--5 to 14 inches; black (10YR 2/1) clay, dark gray (N 4/0) dry; moderate medium angular blocky structure; extremely hard, firm, sticky and very plastic; slight effervescence; slightly alkaline; gradual smooth boundary. (Combined A horizons thickness 5 to 20 inches)
Bw--14 to 30 inches; black (10YR 2/1) clay, dark gray (N 4/0) dry; moderate medium angular blocky structure; extremely hard, firm, sticky and very plastic; common gypsum crystals in the lower part; common medium masses of carbonate; slight effervescence; moderately alkaline; gradual wavy boundary. (0 to 30 inches thick)
Cg1--30 to 46 inches; dark gray (5Y 4/1) clay, dark gray (N 4/0) dry; massive with varves; extremely hard, firm, sticky and very plastic; many medium masses of carbonate; strong effervescence; moderately alkaline; gradual smooth boundary.
Cg2--46 to 60 inches; very dark gray (5Y 3/1) clay, gray (5Y 5/1) dry; massive with varves; extremely hard, firm, sticky and very plastic; common snail shells; common coarse masses of carbonate; strong effervescence; moderately alkaline.
TYPE LOCATION: Dickey County, North Dakota; 50 feet north and 50 feet east of the southwest corner, sec. 32, T. 131 N., R. 59 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 24 to 48 inches in thickness. The 10- to 40-inch particle size control section is silty clay, clay or silty clay loam averaging between 35 and 60 percent clay. Some pedons have an O horizon. Saline phases are recognized.
The A horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 2 or 3, 3 to 5 dry, and chroma of 1 or less. It is a clay, silty clay or silty clay loam. It is slightly acid to moderately alkaline. Some pedons have an Ab horizon.
The B horizon has hue of 10YR, 2.5Y, 5Y, or is neutral, value of 2 to 4 and 4 to 6 dry, and chroma of 2 or less. It is clay, silty clay or silty clay loam. It is moderately alkaline. Some pedons have Bkyg, Bzg, Byg, Bss or Bssy horizons.
The Cg horizon has hue of 2.5Y, 5Y, or is neutral, value of 2 to 5 and 3 to 7 dry, and chroma of 2 or less. It is clay or silty clay. It is clay loam below 40 inches in some pedons. It is moderately alkaline.
COMPETING SERIES: This is the Grano series. Grano soils have mollic epipedons less than 24 inches thick.
GEOGRAPHIC SETTING: The soil is on low, level floodplains of streams. Slope ranges from 0 to 1 percent. Ludden soils formed in clay alluvium that was deposited slowly and the organic matter enrichment of the soil kept pace with the rate of deposition. Mean annual precipitation is 15 to 23 inches and mean annual air temperature is 36 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lamoure, La Prairie and Ryan soils on adjacent floodplains, levees and low terraces. La Prairie soils are fine-loamy and are on slightly higher, better drained areas. Lamoure soils have less clay and more silt. Ryan soils have a natric horizon.
DRAINAGE AND PERMEABILITY: Poorly or very poorly drained. Runoff is negligible to low. Permeability is slow. These soils are flooded and water ponds on them for brief periods. An apparent seasonal high water table is at a depth of 0.5 foot above the surface to 1.5 feet below the surface at some time during the period of March through July in the poorly drained phase. It is at a depth of 0.5 foot above the surface to 1.0 foot below the surface at some time during the period of November through July in the very poorly drained phase. It is at a depth of 2 feet above the surface to 1 foot below the surface at some time during the period of November through July in the ponded phase.
USE AND VEGETATION: Mostly cropped to small grains, hay and pasture. Native grasses are big bluestem, green needlegrass, western wheatgrass and other tall grasses.
DISTRIBUTION AND EXTENT: These soils are extensive. They are adjacent to larger drainageways in central and eastern North Dakota, northeastern South Dakota and east-central Minnesota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Lamoure County, North 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 30 inches (Ap, A, and Bw horizons); Vertisol criteria - cracks greater than 1 cm wide to depth of greater than 50 cm during dry periods; the site will be redescribed in the future to better document other Vertisol criteria.
ADDITIONAL DATA: North Dakota State University Agr. Exp. Sta. sample numbers: S64ND-9-2, S63ND-11-56, S60ND-11-119, S59ND-23-73, and S63ND-23-1.