LOCATION ROSSFIELD IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Rossfield silt loam on a convex southeast-facing slope of 3 percent-cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark brown (10YR 2/2) silt loam; moderate very fine granular structure; friable; slightly acid; abrupt smooth boundary.
A--7 to 11 inches; very dark brown (10YR 2/2) silt loam; moderate very fine granular structure; friable; slightly acid; clear smooth boundary. (Combined thickness of A horizons is 9 to 14 inches.)
AB--11 to 15 inches; mixed very dark grayish brown (10YR 3/2) and dark brown (10YR 3/3) silty clay loam; very dark brown (10YR 2/2) coatings on peds; moderate very fine subangular blocky structure; friable; slightly acid; gradual smooth boundary. (0 to 6 inches thick)
Bw--15 to 26 inches; brown (10YR 4/3) silty clay loam, high content of sand; very dark brown (10YR 3/3) coatings on peds; weak medium subangular blocky structure; friable; slightly acid; clear smooth boundary. (6 to 15 inches thick)
BC--26 to 32 inches; yellowish brown (10YR 5/6) clay loam; brown (10YR 4/3) coatings on peds; weak medium subangular blocky structure; friable; neutral; clear smooth boundary. (0 to 7 inches thick)
2C--32 to 60 inches; olive yellow (2.5Y 6/6) channery fine sandy loam, soft limestone fragments comprise about 20 percent of volume; massive; friable; few roots; violent effervescence; moderately alkaline.
TYPE LOCATION: Franklin County, Iowa; about 1 mile south and 1 mile west of Sheffield; 525 feet east, 70 feet south of the northwest corner of sec. 16, T. 93 N., R. 20 W.
RANGE IN CHARACTERISTICS: Thickness of the surficial sediments over the weathered arenaceous limestone is 20 to 40 inches. Thickness of the solum and depth to carbonates coincide closely with the thickness of the sediments. The mollic epipedon is 10 to 20 inches thick unless eroded.
The A horizon is very dark brown (10YR 2/2) or black (10YR 2/1). It typically is silt loam or loam but ranges to silty clay loam or light clay loam with 27 to 30 percent clay. It is neutral or slightly acid. The AB horizon is very dark grayish brown (10YR 3/2) or dark brown (10YR 3/3) and has the same range of texture and reaction as the A horizon. Some pedons have as much as 25 percent sand in the A horizon, most of which is fine and very fine.
A BA horizon is present in some pedons. Where present, it ranges from 4 to 8 inches thick, has hue of 10YR, value of 3 through 5, and chroma of 2 through 6, with textures like the A horizons. The Bw horizon has hue of 10YR, values of 4 to 5, and chroma of 3 through 6. In pedons where a BC horizon is present, texture of the Bw horizon typically is silty clay loam or silt loam, high in content of sand. In pedons without BC horizons, the Bw horizon is clay loam or loam. The BC horizon has hue of 10YR, values of 4 through 6, and chroma of 4 through 6. The BC horizon typically is clay loam, but ranges to sandy loam and sandy clay loam.
The 2C horizon ranges from channery sandy loam to loam with fragments of limestone. The 2C horizon has hues of 2.5Y or 10YR, values of 5 through 7, and chroma of 6 through 8. Typically 10 to 30 percent of the volume of the 2C horizon consists of pebbles or fragments of limestone. The extreme range is 10 to 40 percent.
COMPETING SERIES: These are the Arbor, Aredale, Bode, Clarion, Cresken, Everly, Farrar, Frontenac, Garmore, Kenyon, Liscomb, Moland, Ocheyedan, and Ostrander series in the same family and the Atkinson, Dinsdale, Dodgeville, Mottland, and Rockton series. The Atkinson, Arbor, Aredale, Bode, Clarion, Cresken, Dinsdale, Everly, Farrar, Garmore, Kenyon, Liscomb, Moland, Ocheyedan and Ostrander series do not have arenaceous limestone within 40 inches of the surface. Frontenac soils have loamy-skeletal 2C horizons that are lower in pH and less effervescent. Atkinson soils have a lithic contact at depths between 40 and 60 inches. Dodgeville and Rockton soils have lithic contacts at depths of 20 to 40 inches and have argillic horizons. Mottland soils are in a coarse-loamy family and have sola formed in less than 20 inches of medium-textured sediments overlying weathered arenaceous limestone.
GEOGRAPHIC SETTING: These soils are on nearly level to gently sloping ridge crests and gently sloping to strongly sloping sideslopes. Slope gradients range from 0 to 14 percent. They formed in 20 to 40 inches of loamy surficial sediments overlying weathered arenaceous limestone. In most places shale underlies the arenaceous limestone below a depth of about 4 to 20 feet. The climate is midcontinental with hot summers and cold winters. Mean annual temperature ranges from about 45 to 49 degrees F, and mean annual precipitation ranges from about 30 to 34 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Dinsdale, Dodgeville, Mottland, and Rockton soils, and the Calamine, Jacwin and Terril soils. The Dinsdale, Dodgeville and Rockton soils typically are somewhat higher on the landscape. Calamine and Jacwin soils are lower on the landscape. Calamine and Jacwin soils have 2B horizons formed in shale. Terril soils formed in loamy local alluvial sediments, have thicker A horizons, and are on footslopes below Rossfield soils.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate in the loamy sediments and moderately rapid in the weathered arenaceous limestone. Surface runoff is slow to rapid.
USE AND VEGETATION: The nearly level to moderately sloping areas are used principally for corn and soybeans. Strongly sloping areas are used mainly for pasture. Native vegetation was prairie grasses.
DISTRIBUTION AND EXTENT: North-central Iowa and northeast Iowa, and southeastern Minnesota. They are inextensive. There are about 8,000 to 10,000 acres in Iowa.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Franklin County, Iowa, 1977.