LOCATION TILFER IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Typic Endoaquolls
TYPICAL PEDON: Tilfer silty clay loam on a nearly level bottom land - cultivated. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; black (N 2/0) silty clay loam, black (10YR 2/1) dry; moderate medium and fine granular structure; friable; strong effervescence; mildly alkaline; clear smooth boundary.
A--8 to 19 inches; black (N 2/0) silty clay loam, very dark gray (10YR 3/1) dry; few fine distinct olive (5Y 5/3) mottles in the lower 3 inches; weak medium subangular blocky structure parting to weak medium granular; friable; slight effervescence; mildly alkaline; clear wavy boundary. (Combined thickness of the A horizons is 12 to 20 inches.)
Bg--19 to 27 inches; light olive gray (5Y 6/2) loam; few fine distinct yellowish brown (10YR 5/6) mottles; weak medium subangular blocky structure; friable; accumulations of black (10YR 2/1) loam in some root channels; slight effervescence; mildly alkaline; gradual smooth boundary. (5 to 11 inches thick)
BCg--27 to 35 inches; olive gray (5Y 5/2) loam; few fine distinct strong brown (7.5YR 5/6) mottles; weak coarse subangular blocky structure; friable; few small rounded hard limestone pebbles and a few small granitic pebbles; slight effervescence; mildly alkaline; abrupt wavy boundary. (0 to 9 inches thick)
R--35 inches; hard fractured limestone bedrock.
TYPE LOCATION: Worth County, Iowa; about 2 miles east and 1 mile south of Kensett; 1,000 feet east and 95 feet north of the southwest corner of sec. 36, T. 99 N., R. 20 W.
RANGE IN CHARACTERISTICS: Solum thickness typically is 24 to 36 inches but ranges from 20 to 40 inches. The solum is terminated by limestone bedrock. Reaction is mildly or moderately alkaline and carbonates typically are present throughout the solum. The calcium carbonate equivalent is about 5 to 15 percent. The Ap or A horizon is black (N 2/0 or 10YR 2/1) and typically silty clay loam but ranges to clay loam or loam. An AB horizon, 3 to 6 inches thick, is present in some pedons. The Bg horizon has hue of 2.5Y or 5Y, value of 4 to 6, and chroma of 1 or 2. It is loam, clay loam, or silty clay loam. The clay content ranges from 16 to 30 percent. The BCg horizon has hue of 2.5Y or 5Y, value of 4 through 6, and chroma of 1, 2, or 3. It is loam or sandy loam. The control section has greater than 15 percent fine sand or coarser. A 2BCg horizon, less than 6 inches thick, is in some pedons. It ranges from gravelly sand to loamy sand, and commonly has 10 to 30 percent pebbles and cobbles.
COMPETING SERIES: These are the Canisteo, Jeffers, and Tappan series in the same family and the Faxon and Talcot series. None of the soils in the same family are underlain by limestone bedrock within a depth of 40 inches. Faxon soils do not have free carbonates in all parts of the 10- to 20-inch depth zone. Talcot soils are underlain by sand and gravel.
GEOGRAPHIC SETTING: Tilfer soils are on low stream benches and bottom lands. The slopes are slightly concave and range from 0 to 2 percent. These soils formed in loamy and silty alluvial sediments overlying limestone bedrock at a depth of 20 to 40 inches. Mean annual temperature ranges from about 45 to 49 degrees F, and mean annual precipitation ranges from about 30 to 33 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Faxon soils and the Harcot, Kensett, and Marshan series. Harcot and Marshan soils are underlain by sand and gravel. Kensett soils have browner B horizons and are somewhat poorly drained. Faxon, Harcot, and Marshan soils are on similar landscape positions as the Tilfer soils. Kensett soils are on slightly higher-lying areas.
DRAINAGE AND PERMEABILITY: Poorly and very poorly drained. Surface runoff is slow. Permeability is moderate. Tilfer soils are subject to occasional but brief flooding.
USE AND VEGETATION: Where drained, Tilfer soils are used for corn, oats, and soybeans. Where not drained, they are used for pasture. Native vegetation was tall prairie grasses and sedges.
DISTRIBUTION AND EXTENT: North central and northeastern Iowa and south central and south-eastern Minnesota. They are inextensive; about 3,000 to 5,000 acres are in Iowa.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Worth County, Iowa, 1972.