LOCATION MCINTOSH MN+SDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Aquic Calciudolls
TYPICAL PEDON: McIntosh silt loam with a slightly convex slope of 1 percent on a ground moraine in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; weak very fine granular structure; friable; slightly sticky; common roots; slightly effervescent; moderately alkaline; abrupt smooth boundary. (6 to 10 inches thick)
Ak--8 to 13 inches; very dark gray (2.5Y 3/1) silt loam, dark gray (10YR 4/1) dry; weak very fine subangular blocky structure; friable; slightly sticky; common roots; few gypsum crystals; violently effervescent; moderately alkaline; clear irregular boundary. (0 to 10 inches thick)
Bk--13 to 29 inches; light olive brown (2.5Y 5/3) silt loam; weak fine subangular blocky structure; friable; slightly sticky; few roots; few gypsum crystals; violently effervescent; moderately alkaline; clear smooth boundary. (6 to 20 inches thick)
2Bk--29 to 34 inches; light olive brown (2.5Y 5/4) loam; weak very fine granular structure; friable; about 3 percent gravel; slightly sticky; few roots; common fine prominent strong brown (7.5YR 5/8) Fe concentrations and few prominent gray (10YR 6/1) Fe depletions; strongly effervescent; moderately alkaline; clear smooth boundary. 0 to 24 inches thick)
2C--34 to 80 inches; light olive brown (2.5Y 5/4) loam; massive; friable; slightly sticky; few small dark colored concretions; many medium prominent gray (10YR 6/1) Fe depletions and few medium prominent strong brown (7.5YR 5/8) Fe concentrations; about 3 percent gravel; slightly effervescent; moderately alkaline.
TYPE LOCATION: Stevens County, Minnesota; about 1 1/2 miles north of Hancock; about 2,060 feet north and 75 feet east of the southwest corner of sec. 27, T. 124 N., R. 41 W., USGS Page Lake quadrangle, lat. 45 degrees 31 minutes 9 seconds N., long. 95 degrees 48 minutes 33 seconds W., NAD83.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 7 to 16 inches. The thickness of the silty mantle and depth to glacial till ranges from 24 to 40 inches. Some pedons have a sandy loam or coarser textured layer as much as 5 inches thick between the two sediments. The upper sediment typically does not have rock fragments, but in some pedons it contains up to 5 percent by volume. The glacial till contains 2 to 10 percent by volume of gravel of mixed lithology. These soils have free carbonates throughout and are slightly alkaline or moderately alkaline throughout. The calcic horizon is within depths of 16 inches and has 20 to 35 percent calcium carbonate equivalent. The control section has 18 to 35 percent clay. Concentrations of gypsum crystals are in some pedons, but they are not diagnostic for the series. Redox depletions occur within 40 inches of the surface.
The A horizon has hue of 10YR or 2.5Y, value of 2 or 3, and chroma of 1 or 2. It typically is silt loam, but the range includes silty clay loam or loam that has less than 15 percent fine sand or coarser.
The Bk horizon has hue of 2.5Y or 10YR, value of 4 to 6, and chroma of 2 to 4. It is silt loam, silty clay loam, or loam that has less than 15 percent fine sand or coarser. Carbonates generally are dispersed throughout the matrix, but some pedons have a few soft concentrations of carbonates.
The 2C horizon has hue of 2.5Y, value of 4 to 6, and chroma of 3 to 6. In some pedons a silt loam or silty clay loam C horizon is immediately below the Bk horizon. Except for the coarser textured layer which is at the base of the upper sediment in some pedons, the 2C horizon is loam or clay loam.
COMPETING SERIES: This is the Rondell series. Rondell soils lack a lithologic discontinuity within the series control section.
GEOGRAPHIC SETTING: These soils have slightly convex slopes with gradient of 0 to 3 percent on glacial till plains or ground moraines. The McIntosh soils formed in 24 to 40 inches of silty lacustrine sediments or loess and calcareous loam or clay loam glacial till. Mean annual air temperature is 38 to 45 degrees F. Mean annual precipitation is 19 to 27 inches. The frost free days range from 120 to 170 days. The elevation above sea level ranges from 850 to 1,950 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Byrne, Doland, Tara, and Winger soils which formed in similar sediments and are members of the same hydrosequence. The Doland and Byrne soils are well drained and are on more sloping terrain. The Tara soils are moderately well drained, but they do not have calcic horizons in the upper part of the solum. The Winger soils are poorly drained and are on lower lying terrain.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is moderate, but ranges to moderately slow in pedons that have clay loam 2C horizons. Surface runoff is slow. Seasonal high saturation occurs as high as 20 inches during the months of April to June in years of normal rainfall.
USE AND VEGETATION: Nearly all of these soils are cultivated. Small grain, corn, and soybeans are the principal crops. Native vegetation is tall grass prairie.
DISTRIBUTION AND EXTENT: MLRA-102A and 56. Western Minnesota and eastern South Dakota. Moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota.
SERIES ESTABLISHED: Grant County, Minnesota, l974.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to 13 inches (Ap and Ak horizons); calcic horizon - the zone from 8 to 34 inches (Ak, Bk and 2Bk horizons); aquic subgroup - based on chroma of 2 above a depth of 40 inches.
This soil was previously classified as an Aeric Calciaquoll. The depth to saturation on the SIR was typically stated to be 2.0 to 4 feet. This depth to saturation excludes an aquic suborder.
ADDITIONAL DATA: See MN Soil Survey CFC No. 2211 and 3171 for laboratory data on representative pedons.