LOCATION ELY IAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Cumulic Hapludolls
TYPICAL PEDON: Ely silty clay loam, on a north-facing, foot slope of 3 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 centimeters; very dark brown (10YR 2/2) silty clay loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure parting to moderate fine granular; friable; few fine roots; few fine vesicular pores; neutral; abrupt smooth boundary.
A1--20 to 38 centimeters; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; weak fine subangular blocky structure parting to moderate fine granular; friable; few fine roots; few fine vesicular pores; neutral; clear smooth boundary.
A2--38 to 61 centimeters; very dark gray (10YR 3/1) silty clay loam, gray (10YR 5/1) dry; weak fine subangular blocky structure parting to moderate fine granular; friable; few fine roots; few fine vesicular pores; neutral; clear smooth boundary. (Combined thickness of the A horizon is 50 to 75 centimeters.)
BA--61 to 81 centimeters; very dark gray (10YR 3/1) silty clay loam, gray (10YR 5/1) dry; moderate very fine and fine subangular blocky structure; friable; few fine roots; few fine vesicular pores; few fine faint dark grayish brown (10YR 4/2) redoximorphic depletions; few fine distinct dark yellowish brown (10YR 4/4) redoximorphic concentrations; neutral; gradual smooth boundary. (0 to 25 centimeters thick)
Bg1--81 to 99 centimeters; dark grayish brown (10YR 4/2) silty clay loam; weak medium prismatic structure parting to weak fine and medium subangular blocky; friable; few fine roots; few fine vesicular pores; common dark gray (10YR 4/1) silt coats on faces of peds; common distinct dark brown (10YR 3/3) organic coats on faces of peds; few fine irregular masses of iron-manganese; few fine distinct yellowish brown (10YR 5/4) redoximorphic concentrations; slightly acid; gradual smooth boundary.
Bg2--99 to 119 centimeters; brown (10YR 4/3) silty clay loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; few fine roots; few fine vesicular pores; common gray (10YR 5/1) silt coats on faces of peds; few fine irregular masses of iron-manganese; common fine faint dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4), and few fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary. (Combined thickness of the Bg horizon is 25 to 66 centimeters.)
BCg--119 to 147 centimeters; grayish brown (10YR 5/2) silty clay loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; few fine roots; few fine vesicular pores; few fine irregular masses of iron-manganese; few fine faint gray (10YR 5/1) redoximorphic depletions; common fine distinct yellowish brown (10YR 5/4) and common fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary. (0 to 30 centimeters thick)
Cg--147 to 203 centimeters; gray (10YR 5/1) and brown (10YR 5/3) silty clay loam; massive; friable; common fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; few fine irregular masses of iron-manganese; slightly acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 108C-Illinois and Iowa Deep Loess and Drift, West-Central Part, Keokuk County, Iowa subset; about 1 mile west and 1 mile north of Keswick; located about 320 feet south and 1,120 feet west of the northeast corner of section 20, T. 77 N., R. 12 W.; USGS What Cheer topographic quadrangle; lat. 41 degrees 27 minutes 58 seconds N. and long. 92 degrees 15 minutes 47 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon--60 to 90 centimeters
Depth to carbonates--greater than 122 centimeters
Content of clay in the particle-size control section (weighted average)--27 to 35 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--1 or 2
Texture--silt loam or silty clay loam
Clay content--20 to 35 percent
Sand content--5 to 20 percent
Reaction--moderately acid to neutral
BA horizon:
Hue--10YR
Value--3
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--24 to 35 percent
Sand content--5 to 20 percent
Reaction--moderately acid to neutral
Bg (upper part):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2
Texture--silty clay loam
Clay content--27 to 35 percent
Sand content--5 to 20 percent
Reaction--moderately acid to neutral
Bg horizon (lower part):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silty clay loam
Clay content--27 to 35 percent
Sand content--5 to 20 percent
Reaction--moderately acid to neutral
Some pedons have few faint and distinct clay films on ped faces and on surfaces along pores and along root channels
Cg horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silt loam or silty clay loam
Clay content--18 to 35 percent
Sand content--5 to 20 percent
Reaction--moderately acid to neutral
COMPETING SERIES: These are the
Lawson,
Littleton and
Smithland series.
Lawson--have a clay content that averages 18 to 30 percent in the particle-size control section and do not have cambic horizons
Littleton--have a clay content that averages 22 to 27 percent in the particle-size control section and have cambic horizons
Smithland--have a clay content that averages 27 to 35 percent in the particle-size control section and have mollic epipedons more than 90 centimeters thick
GEOGRAPHIC SETTING:
Parent material--colluvium
Landform--foot slopes, alluvial fans, and drainageways
Slope--0 to 9 percent
Mean annual air temperature--6 to 11 degrees C
Mean annual precipitation--660 to 965 millimeters
Elevation--155 to 520 meters above sea level
Frost-free period--145 to 205 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Cantril,
Colo,
Gara, and
Otley soils.
Cantril--are in landscape positions similar to those of the Ely soils, do not have mollic epipedons, and have argillic horizons
Colo--are at lower landscape positions on floodplains and drainageways and are frequently saturated at the soil surface during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Gara--are at higher landscape positions on side slopes and have argillic horizons with matrix chroma of 3 to 6
Otley--are at higher landscape positions on side slopes and have a clay content that averages 35 to 40 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs between depths of 0.3 and 1.0 meter during March to June in years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, this saturation is considered apparent
Saturated hydraulic conductivity--1.0 to 10.00 micrometers per second
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, oats, and meadow. The natural 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--Wisconsin driftless section, Dissected till plains
MLRAs--Eastern Iowa and Minnesota Till Prairies (104),
Northern Mississippi Valley Loess Hills (105),
Iowa and Missouri Deep Loess Hills (107),
Illinois and Iowa Deep Loess and Drift (108), and
Iowa and Missouri Heavy Till Plain (109)
LRR M; south-central, eastern, and western Iowa
Extent--moderate
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Iowa County, Iowa, 1965
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (BA, Bg1, and Bg2 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, BA, Bg1, Bg2, BCg, and Cg horizons).
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 81 centimeters (Ap, A1, A2, and BA horizons);
cambic horizon--the zone from a depth of 81 to 147 centimeters (Bg1, Bg2, and BCg horizons);
udic moisture regime.
Field experience suggests that these soils are not saturated with water enough of the time to be classified as Aquolls, even though redoximorphic features in the mollic epipedon and the gray colors of the silt and very fine sand coats in the cambic horizon might be interpreted by some as evidence of poor drainage. The typical pedon lacks clear evidence of an erratic organic matter decrease with depth or a content of organic matter in excess of 0.5 percent at a depth of 125 centimeters below the surface, but other evidence suggests that the series is best classified in a Cumulic subgroup.
Cation-exchange activity class is supported by lab sample 02IA003001, National Soil Survey Laboratory.
Some pedons have a Btg horizon but these do not have the clay increase to meet the requirements of an argillic horizon.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska--pedon 02IA003001 (http://ssldata.sc.egov.usda.gov/);
Laboratory data--Iowa State University, Ames, IA--many pedons