LOCATION PROCTOR IL+INEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Argiudolls
TYPICAL PEDON: Proctor silt loam - in a gently sloping cultivated field at an elevation of 215 meters (705 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 cm (0 to 8 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; common very fine roots; moderately acid; clear smooth boundary.
A--20 to 28 cm (8 to 11 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; friable; common very fine roots; neutral; clear smooth boundary. [Combined thickness of the A horizon is 25 to 51 cm (10 to 20 inches).]
Bt1--28 to 41 cm (11 to 16 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate very fine subangular blocky structure; friable; common very fine roots; common distinct very dark grayish brown (10YR 3/2) organo-clay films on faces of peds; moderately acid; clear smooth boundary.
Bt2--41 to 58 cm (16 to 23 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate very fine and fine subangular blocky structure; friable; common very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; moderately acid; clear smooth boundary.
Bt3--58 to 71 cm 923 to 28 inches); yellowish brown (10YR 5/4) silty clay loam; moderate fine subangular blocky structure; friable; common very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds; moderately acid; clear smooth boundary. [Combined thickness of the Bt horizon is 25 to 76 cm (10 to 30 inches).]
2Bt4--71 to 84 cm (28 to 33 inches); yellowish brown (10YR 5/4) loam; moderate medium subangular blocky structure; friable; few very fine roots; common faint dark yellowish brown (10YR 4/4) clay films on faces of peds; moderately acid; clear smooth boundary.
2Bt5--84 to 117 cm (33 to 46 inches); strong brown (7.5YR 5/6) stratified loam and sandy loam; weak coarse subangular blocky structure; very friable; few very fine roots; common faint brown (7.5YR 4/4) clay films on faces of peds; slightly acid; gradual smooth boundary. [Combined thickness of the 2Bt horizon is 15 to 76 cm (6 to 30 inches).]
2C--117 to 152 cm (46 to 60 inches); strong brown (7.5YR 5/6) stratified sandy loam and loamy sand; massive; very friable; slightly acid.
TYPE LOCATION: Peoria County, Illinois; about 4.8 kilometers (3 miles) northwest of Princeville; 62 meters (204 feet) north and 750 meters (2,460 feet) west of the southeast corner of sec. 3, T. 11 N., R. 6 E.; USGS Princeville, Illinois, topographic quadrangle; lat. 40 degrees 57 minutes 37 seconds N. and long. 89 degrees 48 minutes 07 seconds W., NAD 27; UTM Zone 16, 264189 easting and 4538133 northing, NAD 83.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon ranges from 102 to 165 cm (40 to 65 inches). The thickness of the mollic epipedon ranges from 25 to 51 cm (10 to 20 inches). The depth to horizons with greater than10 percent sand ranges from 51 to 102 cm (20 to 40 inches). The particle-size control section averages between 25 and 35 percent clay and less than 15 percent fine sand or coarser.
The Ap, A, and/or AB horizon has hue of 10YR, value of 2 or 3, and chroma of 1 to 3. It is typically silt loam, but silty clay loam is also included. Reaction ranges from strongly acid to slightly alkaline.
The Bt and/or BA horizon has hue of 7.5YR or 10YR, value of 3 to 6, and chroma of 3 to 6. It is silty clay loam, except the first subhorizon in some pedons is silt loam. Average clay content ranges from 27 to 35 percent, and average sand content is less than 10 percent. Reaction ranges from moderately acid to neutral.
The 2Bt and/or 2BC horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 3 to 6. It is silty clay loam, silt loam, clay loam, sandy clay loam, loam, or sandy loam. Stratification of various textures is common. The content of gravel ranges from a few pebbles to 10 percent. Average clay content ranges from 18 to 32 percent, and average sand content ranges from 15 to 45 percent. Sand content of individual subhorizons ranges from 10 to 75 percent. Reaction ranges from moderately acid to neutral.
Some pedons have a subhorizon just above the 2C horizon that is enriched in clay and has darker color value than the subhorizon above it. Reaction ranges from moderately acid to neutral.
The 2C horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 3 to 6. It is commonly stratified. Dominant textures are sandy loam, loam, or silt loam, with thin strata of loamy sand or sand. Average clay content ranges from 10 to 20 percent. Average sand content ranges from 15 to 75 percent. Sand content of individual subhorizons ranges from 15 to 95 percent. Rock fragment content ranges from 0 to 15 percent gravel. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: These are the Ashdale, Broadwell, Dinsdale, Douglas, Elkhart, Elmont, Healing, Lycurgus, Malcolm, Meadowbank, Mendota, Mickle, Ogle, Osco, Parkway, Plano, Richwood, Ripon, Sibley, Sidell, Tama, Tecumseh, Toddville, Wakenda, and Waupecan series. Ashdale, Elmont, and Ripon soils have a lithic or paralithic contact within a depth of 152 cm (60 inches). Broadwell, Douglas, Elkhart, Mickle, Osco, Parkway, Plano, Richwood, Tama, Toddville, and Wakenda soils do not have horizons with more than 15 percent sand within a depth of 102 cm (40 inches). Dinsdale and Sidell soils have more than 20 percent clay in the lower part of the series control section. Healing soils have subhorizons in the upper part of the series control section that have more than 10 percent sand and/or as much as 5 percent rock fragments. Lycurgus soils average less than 15 percent sand in the lower part of the series control section. Malcolm and Mendota soils are less than 102 cm (40 inches) to the base of soil development. Meadowbank soils average less than 10 percent clay in the lower part of the series control section and have a mean annual soil temperature of more than 13 degrees C (56 degrees F). Ogle soils have hues of 5YR or redder in the matrix of at least one subhorizon in the lower part of the series control section. Sibley soils have a mollic epipedon more than 51 cm (20 inches) thick. Tecumseh soils are deeper than 165 cm (65 inches) to the base of the argillic horizon. Waupecan soils average more than 75 percent sand and more than 15 percent gravel in the lower part of the series control section.
GEOGRAPHIC SETTING: Proctor soils are on outwash plains, stream terraces, kames and eskers of Wisconsinan Age. These soils formed in 51 to 102 cm (20 to 40 inches) of loess and in the underlying stratified loamy outwash. Slope gradients range from 0 to 15 percent. Mean annual air temperature ranges from 8 to 12 degrees C (47 to 54 degrees F), mean annual precipitation ranges from 32 to 40 inches (810 to 1020 mm), frost-free period ranges from 140 to 185 days, and elevation ranges from 207 to 311 meters (680 to1020 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brenton, Drummer, Lawson, and Sawmill soils. The somewhat poorly drained Brenton soils and the poorly drained Drummer soils form a drainage sequence with Proctor soils and are on lower parts of the landscape. Lawson and Sawmill soils have a mollic epipedon more than 61 cm (24 inches) thick and are on nearby flood plains.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is low or medium. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per seconds). Permeability is moderate.
USE AND VEGETATION: Most areas are used for cultivated crops. Principal crops are corn, soybeans, small grain, and hay. Some areas are used for pasture. Native vegetation is prairie grasses.
DISTRIBUTION AND EXTENT: Illinois and Indiana. Extent is large in MLRAs 95B, 108A, 108B, 110, 111D, 115A, and 115C. About 105,000 acres (42,493 hectares) have been correlated.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: Ford County, Illinois, 1929.
REMARKS: Rarely flooded, sandy substratum, and till substratum phases are recognized. These soils will be investigated during MLRA update activities. Possibly new series and interpretation records will be established.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon-the zone from the surface to a depth of 0 to 28 cm (11 inches) (Ap and A horizons); argillic horizon-the zone from approximately 28 to 117 cm (11 to 46 inches) (Bt1, Bt2, Bt3, 2Bt4, and 2Bt5 horizons); a lithologic discontinuity from loess to outwash at a depth of 71 cm (28 inches).