LOCATION BLUE EARTH MN+IAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Mollic Fluvaquents
TYPICAL PEDON: Blue Earth mucky silty clay loam with a plane level slope in the bottom of a former postglacial lake; cultivated field. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 25 cm (0 to 10 inches); black (10YR 2/1) mucky silty clay loam (coprogenous earth), dark gray (5Y 4/1) dry; weak fine granular structure; very friable; few snail shells and fragments of snail shells; slightly effervescent; slightly alkaline; abrupt smooth boundary. [20 to 30 cm (8 to 12 inches thick)]
Cg--25 to 173 cm (10 to 68 inches); very dark gray (10YR 3/1) mucky silty clay loam (coprogenous earth), very dark gray (5Y 3/1) clay loam, and dark olive gray (5Y 3/2) clay loam; few fine prominent dark brown (7.5YR 3/2) and few fine dark reddish brown (5YR 3/2) Fe concentrations; massive with distinct bedding planes; very friable; snail shells ranging from few to many in different parts; strongly effervescent; slightly alkaline.
2Cg1--173 to 183 cm (68 to 72 inches); dark olive gray (5Y 3/2) clay loam; massive; friable; few snail shells; strongly effervescent; slightly alkaline; clear smooth boundary.
2Cg2--183 to 203 cm (72 to 80 inches); very dark gray (5Y 3/1) clay loam; massive; friable; common snail shells; strongly effervescent; slightly alkaline.
TYPE LOCATION: Martin County, Minnesota; about 9 miles south and 7 miles east of Fairmont; about 472 m (1,550 feet) east and 30 m (100 feet) south of the northwest corner of sec. 28, T. 101 N., R. 29 W.; USGS East Chain quadrangle; lat. 43 degrees 31 minutes 44 seconds N. and long. 94 degrees 19 minutes 16 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: The thickness of the coprogenous earth and the depth to loamy glacial till or glacial lacustrine sediments ranges from 76 cm (30 to more than 203 cm (80 inches). Free carbonates are in all parts of these sediments. The coprogenous earth contains from 0 to 25 percent by volume of shell fragments.
The Ap or A horizon has hue of 10YR, 2.5Y, 5Y or neutral, value of 2 or 3 and chroma of 0 to 2. It is mucky silty clay loam, mucky silt loam, mucky silty clay, silt loam or silty clay loam. Some pedons have muck (sapric) surface layers less than 20 cm (8 inches) thick.
The Cg horizon has hue of 10YR, 2.5Y, 5Y or neutral, value of 2 to 4, and chroma of 0 to 2. It is silt loam, silty clay loam, loam, or clay loam, or mucky analogues. The sand fraction is mostly fragments of shells. It is slightly alkaline or moderately alkaline. The calcium carbonate equivalent ranges from 5 to 40 percent.
The 2Cg horizon has hue of 2.5Y or 5Y, value of 3 to 5, and chroma of 1 or 2. It is loam, silt loam, clay loam, or silty clay loam. It contains 0 to 8 percent by volume of rock fragments of mixed lithology. It is slightly alkaline or moderately alkaline and has a calcium carbonate equivalent of 5 to 20 percent. A firm till phase of clay loam with a moist bulk density of 1.6 to 1.9 gm/cc is also recognized.
COMPETING SERIES: These are the Moundprairie and Uturin (T) series. These soils do not have coprogenous earth in the series control section.
GEOGRAPHIC SETTING: These soils have plane or slightly concave slopes with gradient of 0 to 1 percent. They are in small to large lake basins in glacial moraines, flood plains, and lacustrine plains. These basins formerly had lakes, and most of the lakes were drained since settlement. These sediments are underlain by loamy till or lacustrine sediments of the Late Wisconsin glaciation at depths of 76 cm (2.5 to more than 203 cm. Mean annual temperature is 7 to 11 degrees C (45 to 50 degrees F). Mean annual precipitation is 610 mm to 813 mm (24 to 32 inches). Frost free days range from 155 to 200. Elevations above sea level range from 213 m to 480 m (700 to 1570 feet).
GEOGRAPHICALLY ASSOCIATED SOILS: These are other poorly drained and very poorly drained mineral and organic soils within the basin and the Clarion and Lester soils and their respective topographic associates on the adjacent uplands.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained. Surface runoff is negligible to ponded. The saturated hydraulic conductivity, measured in cm per hour, is .05 to 5.1 (.02 to 2.0 inches) in the upper material and .05 to 1.5 (.02 to .6 inches) in the lower part. Seasonal high saturation ranges from plus 91 to 30 cm (3 to 1 foot) for undrained areas of this soil. Areas that are drained have variable depths to saturation based on the effectiveness of the drainage network.
USE AND VEGETATION: Most of this soil is cropped to corn and soybeans. Some is used for pasture or hay. Invasive vegetation (after drainage) is mostly sedges, reeds, and grasses. They lack native vegetation in the conventional sense because these soils were, until recently, sediments in the bottom of lakes.
DISTRIBUTION AND EXTENT: MLRA-103. Southern Minnesota and north-central Iowa. Moderately extensive.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Rock County, Minnesota, 1945.
REMARKS: Problems remain in the classification of these series because no taxon has been defined in Soil Taxonomy that adequately accommodates soils that have formed entirely in coprogenous earth. Diagnostic horizons and features recognized in this pedon are: Surface horizon that meets requirements of a mollic epipedon except it is underlain by stratified C horizon. A firm till substratum is recognized in the geomorphic surface landform of the Kandiyohi till.
In the past some sloping fens were included in the concpet of Blue Earth. Blue Earth is being restricted to ponded basins and lake beds.
ADDITIONAL DATA: Refer to MAES Central File Code No. 1135 for results of some laboratory analysis of a representative pedon of this series.