LOCATION BIRDS IL+IN KY TNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Typic Fluvaquents
TYPICAL PEDON: Birds silt loam - on a nearly level slope in a cultivated field at an elevation of about 415 feet above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak fine granular structure; friable; neutral; abrupt smooth boundary. (5 to 10 inches thick)
ACg--6 to 22 inches; gray (10YR 6/1) silt loam; weak fine granular structure; friable; common fine distinct dark yellowish brown (10YR 4/4) and brown (10YR 5/3) masses of iron accumulation in the matrix; few fine very dark grayish brown (10YR 3/2) masses of iron-manganese accumulation in the matrix; neutral; gradual smooth boundary. (0 to 20 inches thick)
Cg--22 to 60 inches; gray (10YR 6/1) silt loam; massive; friable; common medium and coarse distinct dark yellowish brown (10YR 4/4), prominent light olive brown (2.5Y 5/4), and faint grayish brown (10YR 5/2) masses of iron-manganese accumulation in the matrix; few fine brown (10YR 5/3) iron-manganese concretions throughout; slightly alkaline.
TYPE LOCATION: Lawrence County, Illinois; about 0.2 miles south of Lawrenceville; about 600 feet west and 50 feet north of the center of sec. 13, T. 3 N., R. 12 W.; Lawrenceville, IL topographic quadrangle; latitude 38 degrees, 41 minutes, 41 seconds North and longitude 87 degrees, 41 minutes, 38 seconds West. NAD 27.
RANGE IN CHARACTERISTICS: The particle size control section averages between 18 and 27 percent clay and less than 15 percent fine or coarser sand. Reaction ranges from strongly acid to slightly alkaline to depths greater than 40 inches, but is not strongly acid in all parts within these depths.
The Ap, A, and ACg horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 1 or 2. Many pedons contain redox features with hue of 10YR, 7.5YR, 5YR, 2.5Y, or neutral; value of 2 to 7; and chroma of 0 to 8.
The Cg horizon, to a depth of 40 inches; has hue of 10YR, 2.5Y, or 5Y, value of 4 to 7, and chroma of 1 or 2. Redox features have hue of 7.5YR, 10YR, 2.5Y, or 5Y; value of 3 to 6; and chroma of 2 to 8.
The Cg horizon below 40 inches, has colors similar to the previous part. In some pedons, an Ab horizon of a buried soil has value of 2 or 3 and chroma of 1 or 2. The texture is dominantly silt loam, but some pedons contain strata of silty clay loam, clay loam, loam, or sandy loam.
COMPETING SERIES: These are the Arlynda (t) CA, Killbuck, Nookachamps, Rafton, Skagit, and Southwest soils. Arlinda (t) CA soils have a difference between summer and winter average temperatures of less than 16 degrees. Killbuck soils have a dark colored buried soil within a depth of 40 inches. Nookachamps and Rafton soils have elevation ranges less than 250 feet and have less variation in average temperature. Skagit soils contain more than 20 percent volcanic glass in the control section. Southwest soils have more development and two buried soils in the series control section.
GEOGRAPHIC SETTING: Birds soils are on flood plains of major streams and tributaries. Slopes range from 0 to 2 percent. They formed in silty alluvium derived from loess. Mean annual air temperature ranges from 50 to 58 degrees F., mean annual precipitation ranges from 35 to 45 inches, frost free days ranges from 170 to 210 days, and elevation ranges from 340 feet to 750 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beaucoup, Belknap, Haymond, Petrolia, Wakeland, and Wilbur soils. Beaucoup soils have a mollic epipedon and contain more clay in the control section, and are in positions similar to the Birds soils. Belknap, Haymond, and Wilbur soils are on higher parts of the flood plain or are on narrower and better drained flood plains of adjacent tributary streams. The competing Petrolia soils are on similar or adjacent parts of the flood plains.
DRAINAGE AND PERMEABILITY: Poorly drained and very poorly drained. The potential for surface runoff is negligible to medium. Permeability is moderate or moderately slow in the upper part and moderately slow in the lower part of the control section. These soils are not dry in all parts of the soil moisture control section during the growing season in normal years. The apparent water table ranges from 0.5 feet above to 1 feet below the surface from March through May in drained areas and from 2 feet above to 0.5 feet below the surface from October through July in undrained areas. Flooding ranges from rare to frequent during winter, spring, and after heavy rainfall events.
USE AND VEGETATION: Most areas are cultivated. Corn and soybeans are the principal crops. Some areas are in woodland or pasture. Native vegetation is mixed hardwood forest.
DISTRIBUTION AND EXTENT: Birds soils are in southern and western Illinois, southern Indiana, Kentucky, and Tennessee. They are extensive (over 103,000 acres correlated). MLRAs 105, 108, 113, 114, 115, 120, 131,134.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Lawrence County, Illinois, 1952
REMARKS: In some areas these soils have been described as having weak or moderate blocky structure through the middle part of the control section. These soils will be evaluated during MLRA updating to determine if placement in order Entisols is correct or if new series in order Inceptisols is needed in some areas.
Diagnostic horizons and soil features recognized in this pedon are:
Ochric epipedon - the zone form the surface to a depth of 22 inches (Ap and ACg horizons);
Aquic conditions inferred from dominant chroma of 1 in all layers below the surface layer, endosaturation, Aquic moisture regime;
Mesic temperature regime.