LOCATION MIDDLETOWN ILEstablished Series
The Middletown series consists of very deep, well drained soils formed in 40 to 60 inches of loess and in the underlying eolian loamy sand or sand on uplands. They are moderately permeable in the upper part of the solum and moderately rapid or rapidly permeable in the lower part of the solum and in the substratum. Slopes range from 0 to 18 percent. The mean annual temperature is about 53 degrees F and, the mean annual precipitation is about 37 inches.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Hapludalfs
TYPICAL PEDON: Middletown silt loam, 2 to 5 percent slopes; at an elevation of 605 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine and medium granular structure; friable; common fine roots; neutral; abrupt smooth boundary. (6 to 9 inches thick)
E--9 to 12 inches; yellowish brown (10YR 5/4) silt loam; weak medium platy structure; friable; common fine roots; common distinct dark grayish brown (10YR 4/2) organic coatings on faces of peds; neutral; clear smooth boundary. (0 to 9 inches thick)
Bt1--12 to 17 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular blocky structure; firm; common fine and medium roots; common distinct brown (10YR 4/3) clay films on faces of peds; slightly acid; clear smooth boundary.
Bt2--17 to 35 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; common distinct brown (10YR 4/3) clay films on faces of peds; few fine rounded black (5YR 2/1) iron-manganese accumulations in the matrix; strongly acid; gradual smooth boundary.
Bt3--35 to 44 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate coarse subangular blocky structure; friable; few distinct brown (10YR 4/3) clay films on vertical faces of peds; few fine black (5YR 2/1) iron-manganese accumulations in the matrix; moderately acid; clear smooth boundary. (combined thickness of the Bt horizon is 30 to 42 inches thick)
2Bt4--44 to 47 inches; dark yellowish brown (10YR 4/4) clay loam; weak coarse subangular blocky structure; friable; few distinct brown (10YR 4/3) clay films on vertical faces of peds; moderately acid; abrupt smooth boundary. (combined thickness of the 2Bt horizon is 0 to 14 inches)
2BC1--47 to 52 inches; dark yellowish brown (10YR 4/4) loamy fine sand; weak coarse subangular blocky structure; very friable; moderately acid; gradual smooth boundary.
2BC2--52 to 75 inches; stratified yellowish brown (10YR 5/6) and strong brown (7.5YR 4/6) sand and loamy sand; single grain; loose; 2 inch band of brown (7.5YR 4/4) sandy loam starting at 64 inches; moderately acid; gradual smooth boundary. (combined thickness of the 2BC horizon is 0 to 30 inches)
2C--75 to 80 inches; strong brown (7.5YR 4/6) sand; single grain; loose; slightly acid.
TYPE LOCATION: Sangamon County, Illinois; about 4 miles east of Salisbury, IL; 20 feet west and 1,145 feet south of northeast corner of section 26, T. 17 N., R. 6 W.; U.S.G.S. Athens, IL. topographic quadrangle; lat. 39 degrees 53 minutes 57 seconds N. and long. 89 degrees 43 minutes 51 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: The solum is 45 to 80 inches in thickness. The loess is 40 to 60 inches in thickness over loamy sand or sand. The upper 20 inches of the argillic horizon averages more than 27 percent clay.
The Ap or A horizon has hue of 10YR, value of 4 or 5 and chroma of 2 or 3. It is typically silt loam, but severely eroded pedons include silty clay loam. Reaction is moderately acid to neutral.
The E or BE horizon, where present, has hue of 10YR, value of 4 or 5, and chroma of 2 to 4. Reaction is strongly acid to neutral.
The Bt horizon has hue of 10YR or 7.5YR; value of 4 or 5; and chroma of 3 to 5. The texture typically is silty clay loam but includes silt loam. Reaction is very strongly acid to slightly acid.
The 2Bt horizon, where present, has hue of 10YR or 7.5 YR; value of 4 or 5; and chroma of 3 to 5. The 2Bt horizon is clay loam, fine sandy loam, or loam. It is very strongly acid to neutral.
The 2BC horizon, where present, has hue of 10YR or 7.5YR; value of 4 or 5; and chroma 4 to 6. It typically is loamy fine sand but some pedons are loamy sand, sand or fine sand. The 2BC horizon is strongly acid to neutral.
The 2C horizon is present above a depth of 60 inches in some pedons. It has hue of 10YR or 7.5YR; value of 4 or 5; and chroma of 4 to 6. Texture is fine sand, sand, loamy fine sand, or loamy sand. Reaction is strongly acid to neutral.
COMPETING SERIES: These are the Baraboo, Bertrand, Blackhammer, Camden, Dodge, Dubuque, Fayette, Flagg, Greenridge, Hackers, Jackson, Jemerson, La Farge, Lambeau, Martinsburg, Menfro, Navlys, Palsgrove, Pepin, Piscasaw, Ridgway, Rozetta, Ruma, Rush, Russell, Seaton, St. Charles, Stookey, Sylvan, and Yellowriver. Baraboo, Dubuque, Greenridge, La Farge, Lambeau, Palsgrove, and Pepin soils have a lithic or paralithic contact within a depth of 80 inches. Bertrand, Jackson, Jemerson, Seaton, and Stookey soils average less than 27 percent clay in the particle size control section. Blackhammer, Camden, Ridgway and Rush soils have less than 40 inches of loess or silty material. Dodge, Navlys, Piscasaw, Russell, Sylvan soils have carbonates within a depth of 60 inches. Fayette, Martinsburg, Menfro, Rozetta, and Ruma soils have less than 15 percent sand in all horizons within a depth of 60 inches. Flagg and Hackers soils have hue of 5YR or redder in some part of the series control section. St. Charles and Yellowriver soils average less than 60 percent sand and more than 10 percent clay in the substratum. Uniotown soils have sola less than 40 inches. (Note: The Cadiz, Knowles, Lomira, Sandview, and Westbend soils have not been updated for the addition of cation exchange activity class to their taxonomy. These series may or may not compete when their taxonomy is updated. These soils are listed as Typic Hapludalfs, fine-silty, mixed mesic.)
GEOGRAPHIC SETTING: Middletown soils are on nearly level to strongly sloping uplands along stream valleys. They formed in 40 to 60 inches of loess and in the underlying eolian loamy sand or sand. Slopes range from 0 to 18 percent. Summers are hot and winters are cold. Mean annual temperature varies from 50 to 54 degrees F, and mean annual precipitation varies from 32 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alvin, Fayette, Rozetta and Thebes soils. Alvin soils are on nearby similar landforms, formed in loamy and sandy material and are coarse-loamy. Fayette and Rozetta soils are on nearby landforms where loess is more than 60 inches thick. Thebes soils are on nearby landforms and formed in 20 to 40 inches of loess.
DRAINAGE AND PERMEABILITY: The soils are well drained. The potential for surface water runoff is low or medium. Permeabilty is moderate in the upper part of the solum and moderately rapid or rapid in both the lower part of the solum and the substratum.
USE AND VEGETATION: Largely under cultivation; corn, soybeans, small grain, and hay are major crops. Native vegetation was hardwood trees.
DISTRIBUTION AND EXTENT: Known distribution is central and northern Illinois, and possibly eastern Iowa. Known extent is moderate (12,650 acres in Illinois).
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Logan County, Illinois, 1976.
REMARKS: The type location was moved from Christian County, Illinois to Sangamon County, Illinois and the classification was changed from "Oxyaquic Hapludalfs" to "Typic Hapludalfs" in 2002. Diagnostic horizons and features recognized in this pedon are: ochric epipedon - 0 to 12 inches (Ap, E); argillic horizon - 12 to 47 inches (Bt1, Bt2, Bt3, & 2Bt4).