LOCATION SHAFFTON IA+ILEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Fluvaquentic Hapludolls
TYPICAL PEDON: Shaffton loam - with a 1 percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; black (10YR 2/1) loam (26 percent clay), dark gray (10YR 4/1) dry, very dark brown (10YR 2/2) rubbed; weak fine granular structure; friable; medium acid; abrupt smooth boundary.
A--8 to 13 inches; very dark grayish brown (10YR 3/2) loam (23 percent clay), grayish brown (10YR 5/2) dry, dark brown (10YR 3/3) rubbed; few fine faint dark yellowish brown (10YR 3/4) mottles; weak coarse subangular blocky structure with some tendency to be platy; friable; strongly acid; clear smooth boundary. (Combined thickness of the A horizons is 10 to 15 inches.)
Bw1--13 to 20 inches; brown (10YR 4/3) loam (19 percent clay), dark grayish brown (10YR 4/2) coatings on peds, dark grayish brown (10YR 4/2) kneaded; few fine faint grayish brown (10YR 5/2) mottles; weak medium subangular blocky structure; friable; few fine brown (7.5YR 4/4) accumulations (iron oxides); few fine dark reddish brown (5YR 3/3) concretions (iron oxides); strongly acid; gradual smooth boundary.
Bw2--20 to 30 inches; mottled dark grayish brown (10YR 4/2) and brown (10YR 4/3) loam (19 percent clay), discontinuous grayish brown (10YR 5/2) coatings on peds; weak medium subangular blocky structure; friable; few fine brown (7.5YR 4/4) accumulations (iron oxides); few fine dark reddish brown (5YR 3/3) concretions (iron oxides); strongly acid; gradual smooth boundary.
Bw3--30 to 36 inches; grayish brown (2.5Y 5/2) loam (20 percent clay); many fine and medium distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) mottles; weak medium subangular blocky structure; friable; medium acid; clear smooth boundary. (Combined thickness of the Bw horizons is 18 to 35 inches.)
BC--36 to 39 inches; grayish brown (2.5Y 5/2) loamy sand (9 percent clay); common fine distinct yellowish brown (10YR 5/4) and strong brown (7.5YR 5/6) mottles; weak very coarse subangular blocky structure; very friable; medium acid; clear smooth boundary. (0 to 6 inches)
Cg--39 to 45 inches; gray (5Y 5/1) silty clay loam (29 percent clay); many fine distinct dark yellowish brown (10YR 4/4) mottles; massive; friable; few fine strong brown (7.5YR 4/4) accumulations (iron oxides); slightly acid; clear wavy boundary. (0 to 10 inches thick)
2C--45 to 60 inches; grayish brown (10YR 5/2) coarse sand (4 percent clay); single grain; loose; neutral.
TYPE LOCATION: Clinton County, Iowa; 1 mile east of Wheatland; 1,995 feet east and 800 feet north of the southwest corner of sec. 11, T. 81 N., R. 1 E.
RANGE IN CHARACTERISTICS: Solum thickness commonly is about 36 inches but ranges from 30 to 50 inches. Free carbonates are absent to depths of 60 inches or more. The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 through 3. Typically, it is loam but the range includes clay loam, silty clay loam or silt loam. It ranges from neutral to strongly acid. The Bw horizon is dark grayish brown (10YR or 2.5Y 4/2) or grayish brown (2.5Y 5/2) or has chroma of 3 if mottles with chroma of 2 or less are common, or if faces of peds are 2 chroma or less. Few fine faint mottles of 10YR or 2.5Y hue with value of 5 or 6 and chroma of 2 or 3 are present in the Bw horizon. The BC horizon has common or many fine and medium distinct mottles of 10YR or 7.5Y hue with value of 4 to 6 and chroma of 4 to 6. The B horizon ranges from medium acid to very strongly acid. The C horizon commonly is stratified and ranges in texture from silty clay loam to coarse sand. It is neutral or slightly acid.
COMPETING SERIES: These are the Medway soils. Similar soils are the Amana, Ambraw, Spillville and Turlin. Medway soils range from slightly acid to moderately alkaline in the solum, and typically are calcareous in the C horizon. Amana soils have a fine-silty control section. Ambraw soils are poorly drained and have lower chroma in the B horizon. Spillville and Turlin soils have mollic epipedons more than 24 inches thick.
GEOGRAPHIC SETTING: These soils are on bottomlands and low stream terraces. Slope gradients are commonly 0 to 2 percent. Shaffton soils formed in loamy, noncalcareous, alluvial deposits. Mean annual temperature ranges from about 47 to 52 degrees F, and mean annual precipitation ranges from about 32 to 36 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ambraw, Elvira, Finchford, and Wapsie soils. Ambraw soils are slightly lower in elevation or are in swales. Elvira soils are poorly drained and occupy level or slightly depressional areas. Finchford soils are coarse textured and excessively drained. They are on nearly level stream terraces and adjacent truncated escarpments. Wapsie soils are well drained and are on slightly higher convex slopes.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is slow. Permeability is moderate. Shaffton soils are subject to frequent flooding unless protected by levees.
USE AND VEGETATION: Common crops are corn and soybeans. Some areas are in permanent pasture. The native vegetation was prairie grasses and scattered trees.
DISTRIBUTION AND EXTENT: Along tributaries of the Mississippi River in eastern Iowa and possibly adjacent states. They are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Clinton County, Iowa, 1978.
REMARKS: Stratification and irregular decrease in organic matter required for Fluvaquentic Hapludolls are not readily evident in the horizons described and sampled. However, since the soils are on flood plains and are frequently flooded, this seems to be the best placement.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to a depth of 13 inches (Ap and A horizon) Cambic horizon - the zone from a depth of 13 to 39 inches ( Bw1, Bw2, Bw3, and BC horizons)