LOCATION COTT IAEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Cott clay loam, on a slightly convex but nearly level bottomland, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark brown (10YR 2/2) clay loam, very dark grayish brown (10YR 3/2) dry; cloddy parting to weak fine granular structure; friable; common roots and few fine pores; some mixing of very fine sand in the surface; neutral; abrupt smooth boundary. (6 to 10 inches thick)
A--7 to 13 inches; black (10YR 2/1) clay loam with some mixing of very dark grayish brown (10YR 3/2), very dark grayish brown (10YR 3/2) dry; weak fine subangular blocky and weak fine granular structure; friable; common fine roots and fine pores; neutral; clear smooth boundary. (4 to 10 inches thick)
Bw1--13 to 19 inches; brown (10YR 4/3) and dark grayish brown (10YR 4/2) loam; very dark grayish brown (10YR 3/2) coats on faces of peds; weak fine subangular blocky structure; friable; few fine roots; common fine pores; neutral; clear smooth boundary.
Bw2--19 to 30 inches; brown (10YR 4/3) loam; few fine faint dark grayish brown (10YR 4/2) mottles; weak fine subangular blocky structure; very friable; slightly effervescent; slightly alkaline; clear smooth boundary. (Combined thickness of the Bw horizon is 10 to 24 inches.)
2C--30 to 50 inches; grayish brown (10YR 5/2) with some mixing or mottling of dark yellowish brown (10YR 4/4) fine sand; single grain; loose; slightly effervescent; moderately alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 107B-Iowa and Missouri Deep Loess Hills; Fremont County, Iowa subset; about 3 miles northwest of Hamburg, Iowa; about 1,700 feet west and 180 feet north of the southeast corner of section 8, T. 67 N., R. 42 W.; USGS Sidney quadrangle; lat. 40 degrees 37 minutes 49 seconds N. and long. 95 degrees 41 minutes 01 seconds W., NAD83.
RANGE IN CHARACTERISTICS: The depth to the underlying loamy sand or sand ranges from 20 to 40 inches. Some pedons have a thin sandy loam layer between the upper medium-textured material and the lower coarse-textured material. Carbonates typically are present within depths of 18 to 30 inches.
The Ap horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. Textures include clay loam, loam, or silty clay loam.
An AB horizon is present in some pedons.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 or 3. Chroma of 3 is dominant. Few or common mottles with hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 to 6 are in the lower part of the Bw horizon. The upper part of the Bw horizon is clay loam or loam but grades to loam or sandy loam in the lower part. The clay content of the Bw horizon ranges from 18 to 30 percent. Thin layers contain less than 18 percent clay in some pedons. The sand content ranges form 25 to 60 percent and is dominantly fine sand. The lower part of the Bw horizon is neutral or slightly alkaline.
The 2C horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2. Textures include loamy sand or sand. Most of the sand is fine in size. Chroma is higher where mottled. The mottling pattern is similar to that in the Bw horizon. The 2C horizon is moderately alkaline or slightly alkaline.
COMPETING SERIES: These are the Fairhaven, Kanaranzi, Vanpetten, Wadena, and Waukee series of the same family and the Carmi, Grable, Keg, Percival, Salix, Trempealeau, and Vore series. Fairhaven and Wadena soils have coarser sand in the sola and substrata and, in addition, the substratum typically contains considerable amounts of gravel. Kanaranzi soils have gravelly sand 2C horizons at depths of 14 to 24 inches. Vanpetten soils have a thicker sola and have loamy paleosolic horizons in the lower part of the solum. Waukee soils are deeper to carbonates. Carmi soils have thicker more acid sola and coarser sand and more gravel in the the control section. Grable, Percival, and Vore soils do not have B horizon, typically are calcareous throughout, and contain more silt and less sand in the upper part of the solum. Keg and Salix soils contain more silt and less sand in the upper part and are underlain by calcareous silt loam. Trempealeau soils have reddish hues and formed in residuum weathered from sandstone bedrock.
GEOGRAPHIC SETTING: Cott soils are on nearly level second bottomlands or convex rises within the Missouri River Valley. These rises appear to be remnants of meander scars formed by the movement of the Missouri River channel. They are usually high enough that they have not been subject to overflow or deposition in recent times. Slope gradients range from 0 to 2 percent. Cott soils formed in about 20 to 40 inches of loamy alluvium over sandy river sediments. Mean annual air temperature ranges from 47 to 56 degrees F, and mean annual precipitation ranges from 26 to 32 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Keg and Salix soils and the Buckney, Lakeport, and Luton soils. Keg and Salix soils are on similar landscape positions. Buckney soils are on slightly higher elevations, and Lakeport and Luton soils are on somewhat lower elevations. Buckney soils are coarser textured in the upper part of the sola. Lakeport soils have silt loam material in the lower part of the solum, and Luton soils formed in thick clay sediments.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow. Permeability is moderate in the solum and rapid in the substratum. They are not artificially drained, and cropping is not delayed by wetness.
USE AND VEGETATION: Generally cultivated, with corn and soybeans as the major crops. Small grains and meadow are also grown. Native vegetation was tall prairie grasses.
DISTRIBUTION AND EXTENT: Along the Missouri River in Iowa and possibly adjoining states. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Fremont County, Iowa, 1975.
REMARKS:
Diagnostic horizons and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 13 inches (Ap and A horizons);
cambic horizon--the zone from approximately 13 to 30 inches (Bw1 and Bw2 horizons).