LOCATION MAGNUS ND
Established Series
Rev. CJH
01/2023
MAGNUS SERIES
The Magnus series consists of very deep, moderately well drained, moderately slowly or slowly permeable soils formed in calcareous clayey alluvium. These soils are on low terraces and flood plains and have slopes ranging from 0 to 6 percent. Mean annual air temperature is 42 degrees F, and mean annual precipitation is 16 inches.
TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Vertic Haplustolls
TYPICAL PEDON: Magnus silty clay - cultivated. (Colors are for dry soil unless otherwise stated)
Ap--0 to 7 inches; grayish brown (2.5Y 5/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; strong fine granular structure; hard, friable, few large and common fine roots; many fine pores; slight effervescence; moderately alkaline; abrupt smooth boundary.
A1--7 to 15 inches; dark grayish brown (2.5Y 4/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; weak coarse prismatic and moderate and strong medium and very fine angular blocky structure; very hard, firm; common roots; many fine pores; black (10YR 2/1) moist thin layers; slight effervescence; moderately alkaline; clear smooth boundary.
A2--15 to 26 inches; dark gray (10YR 4/1) silty clay, very dark gray (10YR 3/1) crushed, black (10YR 2/1) moist; moderate coarse prismatic and strong medium and fine angular blocky structure; very hard, firm; common fine pores; shiny pressure faces on surface of peds; few small carbonate nodules; slight effervescence; moderately alkaline; gradual wavy boundary. (Combined A horizons 16 to 30 inches thick)
Bw--26 to 36 inches; grayish brown (2.5Y 5/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; weak coarse prismatic and strong medium angular blocky structure; very hard, firm; shiny pressure faces on vertical faces of prisms; common fine carbonate nodules; slight effervescence; moderately alkaline; gradual wavy boundary. (8 to 14 inches thick)
BC--36 to 54 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and fine angular blocky structure; very hard, firm; a few vertical cracks with pressure faces; common fine carbonate nodules, slight effervescence; moderately alkaline; gradual boundary. (0 to 20 inches thick)
C--54 to 60 inches; light brownish gray (2.5Y 6/2) and light yellowish brown (2.5Y 6/4) stratified silty clay, silt loam and silty clay loam, olive brown (2.5Y 4/4) and dark grayish brown (2.5Y 4/2) moist; massive; firm; few medium carbonate nodules; strong effervescence; moderately alkaline.
TYPE LOCATION: Burleigh County, North Dakota; about 4 miles north of Bismarck; 2,360 feet east and 2060 feet north of southwest corner, sec. 26, T. 138 N., R. 80 W.
RANGE IN CHARACTERISTICS: The control section has one or more dark colored buried surface layers. The mollic epipedon ranges from 16 to 40 inches in thickness.
The A horizon has hue of 10YR or 2.5Y, value of 3 to 5 dry and 2 or 3 moist, and chroma of 2. Some pedons have chroma of 1 in the lower part of the A horizon. It is silty clay or silty clay loam. It is neutral to moderately alkaline. In some pedons, the A horizon does not have carbonates.
The Bw horizon has hue of 10YR or 2.5Y, value of 3 to 5 dry and 2 or 3 moist, and chroma of 1 or 2. It is silty clay or clay. The Bw and BC horizons contain few to common fine nodules or threads of carbonates. They are slightly alkaline or moderately alkaline. Some pedons have Bk and BCk horizons.
The C horizon is silt loam, silty clay loam or silty clay. Some pedons contain thin strata of loam or sandy loam. It is slightly alkaline or moderately alkaline. Gypsum segregations are in the C horizon in some pedons.
COMPETING SERIES: There are no other series in the same family.
GEOGRAPHIC SETTING: Magnus soils are on level to gently sloping low terraces and flood plains that flood. Slopes range from 0 to 6 percent. The soils formed in calcareous clayey alluvium. The climate is cool semiarid. Mean annual air temperature is 34 to 45 degrees F, and mean annual precipitation is 12 to 18 inches. Most of the precipitation comes in the spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Banks,
Farland,
Harriet,
Havrelon,
Lohler,
Mandan,
Parshall,
Wyola,
Straw and
Velva soils. The Banks, Havrelon, Lohler and Velva soils are on nearby flood plains. Farland, Mandan, Parshall and Wyola soils are on nearby higher lying terraces. Harriet and Straw soils are on the same terrace as the Magnus. Banks, Farland, Havrelon, Mandan, Parshall and Velva soils have coarser textures and contain less than 35 percent clay. Harriet soils have natric horizons. Lohler soils do not have mollic epipedons. Wyola soils have argillic horizons. Straw soils are fine-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is negligible to high depending on slope. Permeability is moderately slow or slow. Magnus soils flood for a short time in the spring.
USE AND VEGETATION: Cultivated areas are used for growing small grains, corn, hay, and pasture. Native vegetation is mainly western wheatgrass, green needlegrass, and snowberry.
DISTRIBUTION AND EXTENT: West-central North Dakota, mainly along larger streams. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Burleigh 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 36 inches (Ap, A1, A2 and Bw horizons).
National Cooperative Soil Survey
U.S.A.