LOCATION MANNON ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Hapludalfs
TYPICAL PEDON: Mannon silt loam, on a gently sloping ridgetop, in a cultivated field, at an elevation of 670 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; friable; neutral; abrupt smooth boundary. (6 to 9 inches thick)
E--8 to 12 inches; brown (10YR 4/3) silt loam; weak medium platy structure; friable; neutral; clear smooth boundary. (0 to 6 inches thick)
Bt1--12 to 21 inches; brown (10YR 5/3) silt loam; moderate medium subangular blocky structure; friable; few faint dark brown (10YR 3/3) clay films on faces of peds; slightly acid; clear smooth boundary.
Bt2--21 to 36 inches; brown (10YR 5/3) silt loam; moderate medium subangular blocky structure; friable; common faint brown (10YR 4/3) clay films on faces of peds; neutral; clear smooth boundary.
Bt3--36 to 47 inches; brown (10YR 5/3) silt loam; weak medium subangular blocky structure; friable; common faint brown (10YR 4/3) clay films on faces of peds; common distinct yellowish brown (10YR 5/6) masses of iron accumulation within peds; common prominent light olive gray (5Y 6/2) iron depletions within peds; neutral; clear smooth boundary. (Combined thickness of the Bt horizons is 18 to 40 inches.)
BC--47 to 53 inches; brown (10YR 5/3) silt loam; weak medium subangular blocky structure; friable; common distinct light gray (10YR 7/2) dry silt coats on faces of peds; common medium distinct yellowish brown (10YR 5/6) masses of iron accumulation within peds; common prominent light olive gray (5Y 6/2) iron depletions within peds; slightly acid; clear smooth boundary. (6 to 25 inches thick)
C--53 to 60 inches; brown (10YR 5/3) silt loam; massive; friable; many medium distinct yellowish brown (10YR 5/6) masses of iron accumulation and many medium prominent light olive gray (5Y 6/2) iron depletions within peds; moderately acid.
TYPE LOCATION: Mercer County, Illinois; 3 miles north of the village of Mannon; located about 1,400 feet east and 160 feet south of the northwest corner of section 27, T.15 N., R. 5 W.; USGS Eliza topographic quadrangle; lat. 41 degrees 16 minutes 26 seconds N. and long. 90 degrees 57 minutes 12 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: The control section ranges from moderately acid to very strongly acid in the most acid part. The depth to the base of the argillic horizon is 45 to 60 inches. The soil typically is leached of carbonates to a depth of at least 5 feet.
The A or Ap horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2.
The E horizon ranges from distinct to incipient and is mixed in the Ap horizon in many pedons. Where discernible, it has hue of 10YR, value of 3 or 4, and chroma of 2 or 3. When the soil is dry, common light gray to white silt coats are visible on faces of peds.
The Bt horizon commonly has hue of 10YR, value of 4 or 5 and chroma of 3 to 6. The B horizon is usually free of iron depletions to 30 inches or more. The finest part of the B horizon is silt loam and ranges from 18 to 27 percent clay. The sand content typically is less than 10 percent.
The C horizon typically is silt loam. It has hue of 10YR or 2.5Y, value of 4 to 6 and chroma of 2 to 6.
COMPETING SERIES: These are the Batavia, Bowes, Bunceton, Churchtown, Deroin, Downs, Ella, Festina, Frankville, Gladek, Greenbush, Harvard, Hersey, Juda, Knox, Luana, Massbach, Mellott, Mt. Carroll, Myrtle, Nasset, Newhouse, Shelbyville, Watkins, Waubeek, and Yutan series. Batavia soils have 27 to 35 percent clay in the particle-size control section. Bowes soils have 60 to 90 percent sand in the lower part of the series control section. Bunceton soils have horizons with fragic or brittle characteristics within 40 inches. Churchtown soils have 10 to 55 percent sand in the particle-size control section. Deroin soils have 27 to 35 percent clay in the particle-size control section. Downs soils have 27 to 35 percent clay in the particle-size control section. Ella soils have horizons with 15 to 60 percent sand in the series control section. Festina soils have more sand in the lower part of the series control section. Frankville soils have limestone bedrock within 40 inches. Gladek soils have carbonates within 60 inches. Greenbush soils have 27 to 35 percent clay in the particle-size control section. Harvard soils have 30 to 75 percent sand in the lower part of the series control section. Hersey soils formed in loess and underlying loamy glacial till and have a lithologic discontinuity. Juda soils formed in 20 to 40 inches of loess and underlying moderately fine-textured, calcareous glacial till and have a lithologic discontinuity. Knox soils are less acid in the series control section. Luana soils formed in 20 to 40 inches of loess and underlying residuum weathered from arenaceous limestone and have a lithologic discontinuity. Massbach soils have a paralithic contact within 60 inches. Mellott soils formed in 22 to 40 inches of silty material and underlying glaciofluvium and loamy glacial till and have a lithologic discontinuity. Mt. Carroll soils do not have zones within 60 inches that are frequently saturated for periods longer than one month. Myrtle soils formed in 30 to 50 inches of loess and late Sangamon reddish paleosols formed in sandy loam to loam or clay loam Illinoian glacial till and have a lithologic discontinuity. Nasset soils have limestone bedrock within 55 inches. Newhouse soils have 5 to 35 percent coarse fragments in the lower part of the series control section. Shelbyville soils formed in 24 to 48 inches of loess and underlying residuum from limestone and have a lithologic discontinuity. Watkins soils have 30 to 35 percent clay in the particle-size control section. Waubeek soils formed in 20 to 40 inches of loess and underlying glacial till and have a lithologic discontinuity. Yutan soils have 27 to 35 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: The Mannon soils occupy nearly level to sloping ridgetops and side slopes. Slopes range from 0 to 10 percent. They formed in loess that has been leached of carbonates to depths of 5 feet or more. Mean annual air temperature ranges from 47 to 55 degrees F. Mean annual precipitation ranges from 33 to 38 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Joy, Biggsville, and Seaton soils. Joy soils are on nearly level ridgetops and are wetter. Biggsville and Seaton soils are on similar or more sloping positions. Biggsville soils have surface layers 10 to 20 inches thick. Seaton soils have surface layers 2 to 5 inches thick.
DRAINAGE AND PERMEABILITY: Soil moisture status wet is at 4 to 6 feet from December through June in normal years. Surface runoff is medium. Permeability is moderate.
USE AND VEGETATION: Most areas are cultivated. Corn, soybeans, and small grains are the principal crops. Some areas are in pasture. Native vegetation is prairie grasses and woodlands of widely spaced oak and hickory trees.
DISTRIBUTION AND EXTENT: LRR M, MLRAs 108B, 115C; Northwestern Illinois. This series is of small extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Mercer County, Illinois, 2000.
REMARKS:
Particle-size control section - the zone from 12 to 32 inches;
series control section - the zone from 0 to 60 inches.
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon - the zone from the surface to 8 inches (Ap horizon);
albic horizon - the zone from 8 to 12 inches (E horizon);
argillic horizon - the zone from 12 to 47 inches (Bt1, Bt2, and Bt3 horizons);
iron concentrations and depletions in the lower one-half of the control section;
udic moisture regime.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Second Edition, 1999.
This soil was formerly mapped as a moderately wet phase of the Mt. Carroll series.