LOCATION GWINNER NDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Vertic Argiudolls
TYPICAL PEDON: Gwinner silty clay loam - on 1 percent slopes in small grain field. Soil was moist throughout when described. (Colors are for moist soil unless otherwise stated)
Ap--0 to 7 inches; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure parting to moderate fine granular; slightly hard, friable; slightly sticky and plastic; few very fine roots; neutral; abrupt smooth boundary.
A--7 to 11 inches; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; moderate medium subangular blocky structure; slightly hard, friable; slightly sticky and plastic; few fine roots; neutral; clear wavy boundary. (Combined A horizons 9 to 14 inches thick)
Bt1--11 to 21 inches; black (10YR 2/1) silty clay, very dark gray (10YR 3/1) dry; strong medium prismatic structure parting to moderate fine and medium angular blocky; hard, firm; sticky and plastic; few fine roots; many distinct clay films on faces of peds; neutral; gradual wavy boundary. (8 to 18 inches thick)
2Bt2--21 to 27 inches; dark grayish brown (2.5Y 4/2) clay loam, grayish brown (2.5Y 5/2) dry; moderate medium prismatic structure parting to moderate fine and medium subangular blocky; hard, firm; sticky and plastic; many faint clay films on faces of peds; about 6 percent gravel; common fine and medium streaks of Bt1 material throughout; slightly alkaline; clear wavy boundary. (0 to 15 inches thick)
2Bk--27 to 31 inches; light olive brown (2.5Y 5/3) clay loam, pale yellow (2.5Y 7/3) dry; moderate medium subangular blocky structure; slightly hard, friable; slightly sticky and slightly plastic; about 6 percent gravel; many fine irregular shaped masses of carbonates; violent effervescence; moderately alkaline; gradual wavy boundary.
2Bky--31 to 38 inches; grayish brown (2.5Y 5/2) clay loam, light gray (2.5Y 7/2) dry; common fine distinct light yellowish brown (2.5Y 6/4) redoximorphic concentrations; weak medium subangular blocky structure; slightly hard, friable; slightly sticky and slightly plastic; about 6 percent gravel; common nests of gypsum; common fine irregular shaped masses of carbonates; strong effervescence; moderately alkaline; gradual wavy boundary. (Combined Bk horizons 10 to 40 inches thick)
2C--38 to 60 inches; light olive brown (2.5Y 5/3) loam, light yellowish brown (2.5Y 6/3) dry; common medium faint light yellowish brown (2.5Y 6/4) redoximorphic concentrations and common fine prominent gray (5Y 5/1) redoximorphic depletions; massive; slightly hard, friable; slightly sticky and slightly plastic; about 6 percent gravel; strong effervescence; moderately alkaline.
TYPE LOCATION: Ransom County, North Dakota; about 5 miles south of Lisbon; 1820 feet east and 130 feet south of the northwest corner of Sec. 11, T. 133 N., R. 56 W.
RANGE IN CHARACTERISTICS: Depth to carbonates ranges from 20 to 33 inches. When the soil is dry, cracks 1/2 to 1 inch wide and several feet long extend downward into the upper Bt horizon. The thickness of the mollic epipedon ranges from 16 to 31 inches and includes all or part of the Bt horizon. The depth to the underlying till ranges from 18 to 32 inches. The till has 2 to 10 percent rock fragments of which about 20 to 30 percent are shale. Most pedons redoximorphic features below a depth of 30 inches. The particle-size control section commonly is 35 to 45 percent clay, but has up to 50 percent clay in the upper Bt horizon in some pedons.
The A horizon has hue of 10YR, value of 2 or 3 and 3 or 4 dry, and chroma of 1. It typically is silty clay loam, but the range includes silt loam and clay loam. It is slightly acid to slightly alkaline.
The Bt horizon has hue of 10YR or 2.5Y, value of 2 to 4 and 3 to 5 dry, and chroma of 1 or 2. Tongues or coatings are along vertical ped faces. The Bt horizon is silty clay or clay. It is neutral or slightly alkaline.
The 2Bt horizon has hue of 2.5Y, value 3 or 4 and 4 to 6 dry, and chroma of 2 or 3. Tongues or coatings are along vertical faces of peds. It is slightly alkaline or moderately alkaline.
The 2Bk and 2Bky horizons have hue of 2.5Y, value of 4 or 5 and 5 to 7 dry, and chroma of 2 to 4. They are loam or clay loam and are slightly alkaline or moderately alkaline. They have common or many masses of carbonates. The Bky horizon has few to many nests of gypsum.
The 2C horizon has hue of 2.5Y, value of 4 or 5 and 6 or 7 dry, and chroma of 3. It is loam or clay loam. It is moderately alkaline. Carbonates are disseminated or in few to common masses. It has nests of gypsum in some pedons. It has few to many redoximorphic features.
COMPETING SERIES: These are the Burnel, Harmony, Laplatta and Sieche series. Burnel soils have thinner A horizons and formed in alluvium. Harmony soils are free of rock fragments throughout and formed entirely in glaciolacustrine sediments. Laplatta soils have drier summers and formed in residuum from tuff, conglomerate, sandstone or limestone. Sieche soils have distinct coatings of clean silt and sand grains on faces of peds in the lower A and upper Bt horizons and are on slopes of more than 9 percent.
GEOGRAPHIC SETTING: The Gwinner soils are on level to undulating uplands having plane and concave slopes. Slope gradients typically are less than 3 percent but range from 0 to 6 percent. Gwinner soils formed in clayey glaciolacustrine sediments over loamy till. Mean annual air temperature ranges from 39 to 45 degrees F, and mean annual precipitation from 18 to 22 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aastad, Barnes, Forman, Hamerly, Kranzburg, Lismore, Parnell, Peever, Svea and Tonka soils. Aastad, Kranzburg, Lismore and Svea soils are on similar positions and do not have an argillic horizon. In addition, Aastad and Svea soils are fine-loamy and Kranzburg and Lismore soils are fine-silty. Barnes, Forman and Peever soils are on higher positions and have a mollic epipedon less than 16 inches thick. In addition, Barnes and Forman soils are fine-loamy. Hamerly soils are adjacent to depressions, have a calcic horizon within a depth of 16 inches and are somewhat poorly drained. Parnell and Tonka soils are in depressions and are very poorly and poorly drained, respectively.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is slow or medium. Permeability is slow or moderately slow. A wet soil moisture status is at a depth of 4 to 6 feet.
USE AND VEGETATION: Most areas are cultivated. Small grains and corn are the principal crops. Native vegetation is little bluestem, sideoats grama, blue grama, big bluestem, green needlegrass, western wheatgrass, sedges and forbs.
DISTRIBUTION AND EXTENT: Southeastern North Dakota and possibly northeastern South Dakota. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Ransom County, North Dakota, 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 21 inches (Ap, A and Bt1 horizons); argillic horizon - the zone from 11 to 21 inches (Bt1 horizon); The 2Bt2 horizon has clay films but not the clay increase to be argillic.