LOCATION LAWNDALE ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Argiudolls
TYPICAL PEDON: Lawndale silt loam - on a northeast-facing slope about 1 percent in a cultivated field. (Colors are for moist soil unless otherwise stated.
Ap--0 to 6 inches; very dark brown (10YR 2/2) silt loam, dark gray (10YR 4/1) dry; moderate very fine granular structure; friable; black (10YR 2/1) organic coats on faces of peds; moderately acid; abrupt smooth boundary.
A1--6 to 13 inches; very dark brown (10YR 2/2) silt loam, dark gray (10YR 4/1) dry; moderate medium granular structure; friable; black (10YR 2/1) organic coats on faces of peds; moderately acid; clear smooth boundary.
A2--13 to 18 inches; very dark grayish brown (10YR 3/2) silt loam, dark gray (10YR 4/1) dry; moderate coarse granular structure; friable; very dark brown (10YR 2/2) organic coats on faces of peds; moderately acid; gradual smooth boundary. (Combined thickness of the A horizons is 10 to 20 inches.)
Bt1--18 to 23 inches; dark grayish brown (10YR 4/2) silty clay loam; moderate very fine subangular blocky structure; firm; many faint dark grayish brown (10YR 4/2) clay films and common very dark brown (10YR 2/2) organic coats on faces of peds; moderately acid; clear smooth boundary.
Bt2--23 to 31 inches; brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure; firm; many distinct dark grayish brown (10YR 4/2) clay films on faces of peds; common fine distinct light brownish gray (10YR 6/2) iron depletions and yellowish brown (10YR 5/8) masses of iron and manganese accumulation; few fine black concretions (iron and manganese oxides); moderately acid; clear smooth boundary.
Bt3--31 to 38 inches; yellowish brown (10YR 5/6) silty clay loam; moderate medium subangular blocky structure; firm; common distinct dark grayish brown (10YR 4/2) clay films on faces of peds; few fine faint yellowish brown (10YR 5/8) masses of iron and manganese accumulation; few fine distinct light brownish gray (10YR 6/2) iron depletions; few fine black concretions (iron and manganese oxides); moderately acid; clear smooth boundary.
Bt4--38 to 44 inches; yellowish brown (10YR 5/6) silt loam; moderate coarse subangular blocky structure; friable; common distinct dark grayish brown (10YR 4/2) clay films on faces of peds; few fine faint yellowish brown (10YR 5/8) masses of iron and manganese accumulation; slightly acid; abrupt smooth boundary. (Combined thickness of the Bt horizons is 22 to 36 inches.)
2Bt5--44 to 52 inches; dark yellowish brown (10YR 3/4) loamy fine sand; weak coarse subangular blocky structure; very friable; few distinct dark grayish brown (10YR 4/2) clay films on faces of peds; slightly acid; gradual smooth boundary. (5 to 10 inches thick)
2C--52 to 60 inches; yellowish brown (10YR 5/8) fine sand; single grain; loose; slightly acid.
TYPE LOCATION: Logan County, Illinois; about 3 miles south and 4 miles west of Emden; 2115 feet west and 665 feet south of northeast corner, sec. 21, T. 21 N., R. 4 W.
RANGE IN CHARACTERISTICS: The solum typically is 45 to 55 inches in thickness but some are 60 inches or more in thickness. Loess thickness ranges from 40 to 60 inches. Sand content in the loess is less than 10 percent. The particle size control section averages between 27 and 33 percent clay. The solum extends into the underlying eolian sandy material 5 or 10 inches in all pedons. Depth to carbonates is greater than 60 inches.
The Ap or A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. It is moderately acid to neutral.
Some pedons have an AB or a BA horizon as much as 6 inches thick. They are silt loam or silty clay loam.
The Bt horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 to 6. The higher chroma generally occurs in the lower part. Chroma of 2 occurs within 6 inches below the mollic epipedon either in the matrix or in the mottles in combination with value of 4 and hue of 10YR. The Bt horizon typically is mottled. It is dominantly silty clay loam, but subhorizons in the upper or lower part are silt loam in some pedons. Reaction is moderately acid or slightly acid in at least one subhorizon, and is neutral in the upper part or in the lower part in some pedons.
The 2Bt or 2BC horizon has hue of 10YR or 2.5Y, value of 3 to 5, and chroma of 2 to 6, and is mottled in some pedons. It is loamy fine sand, loamy sand, fine sand, or sand. Sand content ranges from 75 to 90 percent. Reaction ranges from moderately acid to neutral.
The C horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 through 8. It is loamy fine sand, loamy sand, fine sand, or sand. Sand content ranges from 80 to 95 percent. Fine sand and very fine sand dominate the sand fraction. Reaction ranges from moderately acid to neutral.
COMPETING SERIES: These are the Arrowsmith, Bearpen, Brenton, Edwardsville, Elburn, Grundelein, Hacreek, Harco, Higginsville, Keller, Lafayette, Lisbon, Lismod, Loran, Mundelein, Muscatune, Nevin, Raub, Rooks, Rowley and Shannondale series in the same family and the Frankenmuth series in a closely related family (cation exchange activity class not assigned). All of these series except Bearpen, Elburn, Frankenmuth, Grundelein, Lafayette, Rowley and Shannondale soils average less than 80 percent sand in the lower part of the series control section. Bearpen and Rowley soils average less than 27 percent clay in the particle size control section. Elburn soils do not have dominantly fine and very fine sand in the lower part of the series control section and typically average less than 80 percent total sand. Frankenmuth soils are less than 45 inches to the base of soil development. Grundelein and Lafayette soils average more than 15 percent rock fragments in the lower part of the series control section. Shannondale soils have more less than 10 percent sand in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: Lawndale soils are on nearly level to gently rolling uplands. They formed in 40 to 60 inches of loess or other silty material and in the underlying eolian loamy fine sand or fine sand. The source of the sandy material was nearby stream valleys or outwash plains. Slopes range from 0 to 3 percent. Mean annual temperature ranges from 51 to 53 degrees F, and annual precipitation ranges from 36 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Broadwell, Ipava, Muscatune, and Sable soils. The well drained Broadwell soils are in the drainage sequence with Lawndale soils and are on higher parts of the landscape nearby. The poorly drained Sable soils occur in low areas in the vicinity of Lawndale soils, and contain less sand in the lower part of the solum. Muscatune and Ipava soils are associated with Lawndale soils in similar areas that have loess greater than 5 feet in thickness. They contain less sand in the lower part of the sola.
DRAINAGE AND PERMEABILITY: Lawndale soils are somewhat poorly drained. Potential for surface runoff is low or medium. Permeability is moderate in the upper part of the solum and moderately rapid or rapid in the lower part and in the substratum. The depth to the top of an apparent high water ranges from 1 to 2 feet in the spring in normal years.
USE AND VEGETATION: Most areas are cultivated. Corn, soybeans, small grain, and meadow are major crops. Native vegetation is prairie grasses.
DISTRIBUTION AND EXTENT: Central Illinois. Known extent is small.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Logan County, Illinois, 1976.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
mollic epipedon - the zone from the surface to a depth of 18 inches (Ap, A1 and A2 horizons);
argillic horizon - the zone from a depth of 18 to 52 inches (Bt1, Bt2, Bt3, Bt4, and 2Bt5 horizons).