LOCATION BIRDS                   IL+IA IN KY TN

Established Series


The Birds Series consists of very deep, poorly drained and very poorly drained soils formed in silty alluvium on flood plains. Slopes range from 0 to 2 percent. Mean annual precipitation is about 1067 mm (42 inches), and mean annual air temperature is about 12.2 degrees C (54 degrees F).

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 126.5 meters (415 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 cm (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. [12.5 to 25 cm (5 to 10 inches) thick]

ACg--15 to 56 cm (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 oxidized iron 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 51 cm (0 to 20 inches) thick]

Cg--56 to 152 cm (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 oxidized iron and manganese 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.; USGS Lawrenceville, IL topographic quadrangle; lat. 38 degrees 41 minutes 42.6 seconds N. and long. 87 degrees 41 minutes 45.9 seconds W., UTM Zone 16, 439467 easting and 4283182 northing, NAD 83.

Particle-size control section: averages 18 to 27 percent clay and less than 15 percent fine or coarser sand
Reaction: strongly acid to slightly alkaline to depths greater than 102 cm (40 inches), but is not strongly acid in all parts within these depths

Ap, A and ACg horizon:
Hue: 10YR, 2.5Y, or 5Y
Value: 2 to 6
Chroma: 1 to 3
Texture: silt loam
Thickness: 5 to 15 cm (2 to 6 inches) in pedons with A horizons or value less than 3
Other features: 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.

Cg horizon, to a depth of 102 cm (40 inches):
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 7
Chroma: 1 or 2
Texture: silt loam
Other features: Redox features have hue of 7.5YR, 10YR, 2.5Y, or 5Y; value of 3 to 6; and chroma of 2 to 8.

Cg horizon, below 102 cm (40 inches):
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 7
Chroma: 1 or 2
Texture: dominantly silt loam, but some pedons contain thin strata of silty clay loam, clay loam, loam, sandy loam, loamy sand or sand
Other features: In some pedons below a depth of 102 cm (40 inches), an Ab horizon of a buried soil has value of 2 or 3 and chroma of 1 or 2.

COMPETING SERIES: These are the Killbuck and Southwest soils. Killbuck and Southwest soils have a dark colored buried soil within a depth of 102 cm (40 inches).

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 9 to 14.4 degrees C (48 to 58 degrees F), mean annual precipitation ranges from 840 to 1220 mm (33 to 48 inches), frost free days ranges from 150 to 230 days, and elevation ranges from 104 to 274 meters (340 to 900 feet) above sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beaucoup, Belknap, Haymond, Petrolia, Wakeland, and Wilbur soils. Beaucoup soils have a mollic epipedon, average more than 27 percent clay in the particle-size control section, and are in positions similar to the Birds soils. Belknap, Haymond, Wakeland and Wilbur soils average less than 18 percent clay in the particle-size control section and are on higher parts of the flood plain or are on narrower and better drained flood plains of adjacent tributary streams. The Petrolia soils average more than 27 percent clay in the particle-size control section and are on similar or adjacent parts of the flood plains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained and very poorly drained. The apparent water table ranges from 31 cm (1.0 foot) above to 31 cm (1 foot) below the surface from January through June in drained areas and from 61 cm (2 feet) above to 15 cm (0.5 feet) below the surface from October through September in undrained areas. Flooding ranges from rare to frequent during winter, spring, and after heavy rainfall events. Saturated hydraulic conductivity is moderately high or high (1.41 to 14.11 micrometers/sec) in the upper part and moderately high (1.41 to 4.23 micrometers/sec) in the lower part of the series control section. Permeability is moderate or moderately slow (0.2 to 2.0 inches per hour) in the upper part and moderately slow (0.2 to 0.6 inches per hour) in the lower part of the series control section. The potential for surface runoff is negligible to medium. These soils are not dry in all parts of the soil moisture control section during the growing season in normal years.

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. See Additional Data section for native vegetative cover in Iowa.

DISTRIBUTION AND EXTENT: Birds soils are in southern and western Illinois, eastern Iowa, southern Indiana, Kentucky, and Tennessee. They are extensive (over 156,000 acres correlated) and occur in MLRAs 105, 108B, 113, 114A, 114B, 115A, 115B, 115C, 120A, 120B, 120C, 122, 131A, and 134. The type location is in MLRA 115A.


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 series 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 56 cm (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.

ADDITIONAL DATA: In Iowa, the native vegetative cover is a mixed herbaceous and woody community commonly inhabited with Silver Maples, Green Ashes, Eastern Cottonwoods, Black Elderberries, Black Willows, Riverbank Grapes, White Cutgrasses, Wood Reedgrasses, Virginia Wildryes, Sensitive Ferns, Wood Nettles, Canadian Clearweeds, Late Goldenrods, and Yellow Jewelweeds. Source: Iowa State Office, Natural Resources Conservation Service, Des Moines, IA.

National Cooperative Soil Survey