LOCATION ION IAEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Mollic Udifluvents
TYPICAL PEDON: Ion silt loam, on a nearly level floodplain, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 centimeters (0 to 9 inches); very dark grayish brown (10YR 3/2) silt loam; grayish brown (10YR 5/2) dry; weak fine and very fine subangular blocky structure; friable; few very fine roots; moderately alkaline; slightly effervescent; clear smooth boundary. [13 to 23 centimeters (5 to 9 inches) thick]
C1--23 to 84 centimeters (9 to 33 inches); stratified very dark grayish brown (10YR 3/2), very dark gray (10YR 3/1), grayish brown (10YR 5/2) and brown (10YR 5/3) silt loam; massive with weak thin alluvial stratification; friable; few very fine roots; moderately alkaline; slightly effervescent; clear smooth boundary.
C2--84 to 91 centimeters (33 to 36 inches); stratified black (10YR 2/1), very dark grayish brown (10YR 3/2), grayish brown (10YR 5/2) and brown (10YR 5/3) silt loam; massive with weak thin alluvial stratification; friable; moderately alkaline; slightly effervescent; clear smooth boundary. [Combined thickness of the C horizon is 38 to 79 centimeters (15 to 31 inches).]
Ab--91 to 152 centimeters (36 to 60 inches); black (10YR 2/1) silt loam; moderate fine and very fine subangular blocky structure; friable; few small snail shell fragments; moderately alkaline; slightly effervescent.
TYPE LOCATION: Major Land Resource Area (MLRA) 105-Northern Mississippi Valley Loess Hills; Allamakee County, Iowa subset; about 6 miles west of Dorchester; about 549 meters (1,800 feet) east and 564 meters (1,850 feet) south of northwest corner of section 30, T. 100 N., R. 6 W.; USGS Dorchester quadrangle; lat. 43 degrees 27 minutes 12 seconds N. and 91 degrees 36 minutes 14 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--0 to 25 centimeters (0 to 10 inches)
Depth to buried horizons--51 to 102 centimeters (20 to 40 inches)
Content of clay in the particle-size control section (weighted average)--10 to 18 percent
Content of sand in the particle-size control section (weighted average)--less than 15 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--2
Texture--silt loam
Clay content--10 to 18 percent
Sand content--10 to 20 percent
Reaction--neutral to moderately alkaline
C horizon:
Hue--10YR
Value--2 to 5
Chroma--1 or 3
Texture--silt loam
Clay content--10 to 18 percent
Sand content--less than 15 percent
Reaction--slightly alkaline or moderately alkaline
Ab horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam
Clay content--12 to 22 percent
Sand content--10 to 20 percent
Reaction--slightly acid to slightly alkaline
COMPETING SERIES: These are the
Haynie and
McPaul series.
Haynie--do not have a buried horizon within a depth of 102 centimeters (40 inches) and have a matrix hue of 2.5Y in the series control section
McPaul--do not have a buried horizon within a depth of 102 centimeters (40 inches) and do not have a matrix hue of 2.5Y in the series control section
GEOGRAPHIC SETTING:
Parent material--alluvium
Landform--floodplains
Slopes--0 to 2 percent
Elevation--198 to 335 meters (650 to 1,100 feet) above sea level
Mean annual air temperature--7 to 10 degrees C (45 to 50 degrees F)
Mean annual precipitation--74 to 97 centimeters (29 to 38 inches)
Frost-free period--145 to 175 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Eitzen,
Elon, and
Orion soils.
Elon--are in similar landscape positions to those of the Ion soils and have a frequently saturated zone within depths of 0.6 to 1.2 meters (2 to 4 feet) in normal years
Eitzen--are in similar landscape positions to those of the Ion soils, have a clay content of 18 to 27 percent in the particle-size control section, and do not have carbonates in the series control section
Orion--are in similar landscape positions to those of the Ion soils, have a clay content of 10 to 18 percent in the particle-size control section, and do not have carbonates in the series control section
DRAINAGE AND PERMEABILITY:
Drainage class--moderately well drained--a frequently saturated zone occurs within depths of 1.2 to 1.8 meters (4 to 6 feet) during the wettest periods of normal years
Saturated hydraulic conductivity--moderately high or high
Surface runoff potential--negligible or low
Flooding--occasional for brief or very brief periods during the months of February to November from rainfall events and snowmelt
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans, small grains, and hay. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Wisconsin Driftless section
MLRA--Northern Mississippi Valley Loess Hills (105)
LRR M; northeastern Iowa
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Allamakee County, Iowa, 1990.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 39 inches) (C1, C2, and Ab horizons);
series control section--the zone from the surface to a depth of 150 centimeters (0 to 59 inches) (Ap, C1, C2, and Ab horizons).
Diagnostic horizons and features recognized in this pedon:
Ochric epipedon--the zone from the surface to a depth of 23 centimeters (0 to 9 inches) (Ap horizon);
udic moisture regime.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, ninth edition, 2003.