LOCATION OCHEYEDAN IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Ocheyedan loam, on a convex slope of about 1 percent, in a cultivated field. (Colors are for moist conditions unless otherwise stated.)
Ap--0 to 18 centimeters; black (10YR 2/1) loam; very dark gray (10YR 3/1) dry; weak fine granular structure; friable; slightly acid; clear smooth boundary.
A--18 to 36 centimeters; black (10YR 2/1) loam; very dark gray (10YR 3/1) dry; weak fine and medium granular structure; friable; a few brown (10YR 4/3) earthworm casts; slightly acid; gradual smooth boundary. (Combined thickness of the A horizon is 25 to 40 centimeters.)
Bw1--36 to 53 centimeters; brown (10YR 4/3) loam; weak fine subangular blocky structure; friable; a few black (10YR 2/1) earthworm casts; neutral; gradual smooth boundary.
Bw2--53 to 66 centimeters; brown (10YR 4/3) sandy clay loam; weak fine subangular blocky structure; friable; a few black (10YR 2/1) earthworm casts; neutral; gradual smooth boundary.
Bw3--66 to 86 centimeters; dark yellowish brown (10YR 4/4) fine sandy loam; weak medium subangular blocky structure; friable; many fine pores; neutral; gradual smooth boundary. (Combined thickness of the Bw horizon is 40 to 60 centimeters.)
2BC--86 to 112 centimeters; mixed dark yellowish brown (10YR 4/4) and grayish brown (2.5Y 5/2) silt loam; weak medium subangular blocky structure; friable; common fine distinct light olive brown (2.5Y 5/6) redoximorphic concentrations; slightly alkaline; gradual smooth boundary. (10 to 20 centimeters thick)
2Cg--112 to 165 centimeters; grayish brown (2.5Y 5/2) silt loam; massive; friable; common fine and medium very pale brown (10YR 8/2) masses of carbonate; common medium prominent strong brown (7.5YR 5/6) and yellowish red (5YR 4/6) redoximorphic concentrations; strongly effervescent; slightly alkaline; abrupt smooth boundary
3C--165 to 200 centimeters; yellowish brown (10YR 5/4) and dark yellowish brown (10YR 4/6) clay loam; massive; firm; common fine and medium very pale brown (10YR 8/2) masses of calcium carbonate; common medium distinct grayish brown (2.5Y 5/2) redoximorphic depletions; about 3 percent gravel; strongly effervescent; slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 107A-Iowa and Minnesota Loess Hills, Clay County, Iowa subset; about 1 1/4 miles northwest of Everly; located about 960 feet north and 710 feet east of the southwest corner of section 28, T. 97 N., R. 38 W.; USGS Everly topographic quadrangle; lat. 43 degrees 11 minutes 11 seconds N and long. 95 degrees 20 minutes 44 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 40 centimeters
Depth to carbonates--50 to 140 centimeters
Clay content in the particle-size control section (weighted average)--18 to 25 percent
Sand content in the particle-size control section (weighted average)--30 to 55 percent
A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam or clay loam
Clay content--18 to 28 percent
Sand content--30 to 50 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral
Bw horizon:
Hue--10YR
Value--4
Chroma--3 or 4
Texture--loam, sandy clay loam, sandy loam, or fine sandy loam
Clay content--12 to 28 percent
Sand content--35 to 60 percent
Rock fragment content--0 percent
Reaction--slightly acid to slightly alkaline
2BC or 2C horizon:
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--1 to 6
Texture--silt loam, sandy loam, or sandy clay loam
Clay content--10 to 30 percent
Sand content--30 to 65 percent
Rock fragment content--0 percent
Reaction--neutral to moderately alkaline
Moist bulk density--1.45 to 1.70 g/cc
Some pedons have lenses of loamy sand, less than 15 centimeters thick, interbedded with the silt loam material
3C or 3BC horizon:
Hue--2.5Y or 10YR
Value--4 to 6
Chroma--2 to 6
Texture--loam or clay loam
Clay content--18 to 35 percent
Sand content--30 to 50 percent
Rock fragment content--2 to 10 percent
Reaction--neutral to moderately alkaline
Moist bulk density--1.45 to 1.70 g/cc
Lacustrine substratum, below a depth of 150 centimeters (when present):
Hue--2.5Y or 5Y
Value--4 to 6
Chroma--1 to 4
Texture--silt loam, silty clay loam, silty clay, and clay
Clay content--20 to 42 percent
Sand content--2 to 20 percent
Rock fragment content--0 percent
Reaction--slightly alkaline or moderately alkaline
COMPETING SERIES: These are the
Arbor
Aredale,
Bode,
Clarion,
Cresken,
Everly,
Farrar,
Frontenac,
Garmore,
Germantown,
Kenyon,
Limecreek,
Liscomb,
Moland,
Neeper,
Omsrud,
Ostrander, and
Rossfield series.
Arbor--have a clay content that averages 25 to 35 percent in the particle-size control section
Aredale--do not have carbonates within a depth of 150 centimeters
Bode--have a clay content that averages 28 to 36 percent in the particle-size control section
Clarion--have a rock fragment content of 1 to 10 percent in the series control section
Cresken--have a moist bulk density range of 1.75 to 1.9 gm/cc in the lower half of the series control section
Everly--have a sand content that averages 20 to 30 percent in the particle-size control section
Farrar--have a sand content that averages more than 60 percent in the upper third of the series control section
Frontenac--have a rock fragment content of 35 to 70 percent in the lower half of the series control section
Garmore--have a rock fragment content of 2 to 10 percent in the series control section
Germantown--have a lithic contact with quartzite bedrock within a depth of 100 centimeters
Kenyon--have a rock fragment content of 1 to 10 percent in the series control section
Limecreek--have a sand content that averages 14 to 20 percent in the upper third of the series control section
Liscomb--do not have a frequently saturated zone within a depth of 1.8 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Moland--have a rock fragment content of 2 to 15 in the lower half of the series control section
Neeper--do not have carbonates within a depth of 150 centimeters
Omsrud--have a rock fragment content of 2 to 10 percent in the series control section
Ostrander--have a moist bulk density of 1.65 to 1.9 g/cc in the lower third of the series control section
Rossfield--have a rock fragment content of 10 to 40 percent, mostly arenaceous limestone, in the lower half of the series control section
GEOGRAPHIC SETTING:
Parent material--loamy glacial sediments of mixed lithology
Landform--nearly level to undulating uplands, moraines, or glacial outwash terraces
Slope--0 to 9 percent
Elevation--300 to 610 meters above mean sea level
Mean annual air temperature--6 to 11 degrees C
Mean annual precipitation--585 to 890 millimeters
Frost-free days--150 to 200 days
GEOGRAPHICALLY ASSOCIATED SOILS: Near the type location, these are the
Afton,
Fostoria, and
Gillett Grove soils.
Afton--are on lower landscape positions on nearly level upland drainageways and are saturated at the surface to within 0.3 meter of the surface during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Fostoria--are on slightly lower landscape positions and have a frequently saturated zone between depths of 0.3 and 1.0 meter during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Gillett Grove--are on lower landscape positions in nearly level upland flats and swales and are frequently saturated from the surface to a depth of 0.3 meter during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs between a depth of 1.0 and 1.8 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saturated hydraulic conductivity--1.0 to 10.0 micrometers per second
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. 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 sections--Dissected till plains and Western lake section
MLRAs--Loess Uplands (102C), Central Iowa and Minnesota Till Prairies (103), and Iowa and Minnesota Loess Hills (107A)
LRR M--northwestern Iowa and southern Minnesota
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana; MLRA SSO 10-6 (Atlantic, Iowa)
SERIES ESTABLISHED: Clay County, Iowa, 1973.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone the surface to a depth of 150 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the soil surface to a depth of 36 centimeters (Ap and A horizons);
cambic horizon--the zone from a depth of 36 to 112 centimeters (Bw1, Bw2, Bw3, and 2BC horizons);
udic moisture regime.
This series concept previously did not recognize soil saturation in the lower third of the series control section. Based on redoximorphic features and field observations, the concept was changed to that of a soil with saturation in the lower part of the pedon in spring.
A lacustrine substratum phase has been correlated in Clay County, Iowa and is of very minor extent. It is on a lake plain.
In parts of the MLRA this drainage class is called well drained based on the Soil Survey Manual. Drainage class is a state interpretation.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.