LOCATION CALCO IA+IL KS MN NE SDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Cumulic Endoaquolls
TYPICAL PEDON: Calco silty clay loam, on a 1 percent slope, on a floodplain, in a cultivated field, at an elevation of about 401 meters above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 centimeters; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; weak fine subangular blocky structure parting to weak fine granular; friable; few medium prominent strong brown (7.5YR 5/8) redoximorphic concentrations; common fine fragments of snail shells; slightly effervescent; slightly alkaline; clear smooth boundary.
A1--20 to 43 centimeters; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure parting to moderate fine granular; friable; common medium black (10YR 2/1) worm casts; slightly effervescent; slightly alkaline; gradual wavy boundary.
A2--43 to 79 centimeters; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; friable; common medium black (10YR 2/1) worm casts; slightly effervescent; moderately alkaline; gradual wavy boundary.
A3--79 to 107 centimeters; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; friable; few fine prominent light brownish gray (2.5Y 6/2) redoximorphic depletions; slightly effervescent; moderately alkaline; gradual wavy boundary.
A4--107 to 127 centimeters; black (10YR 2/1) silty clay loam, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure; friable; slightly effervescent; moderately alkaline; gradual wavy boundary.
Bg--127 to 165 centimeters; very dark gray (N 3/0) silty clay loam; weak fine and medium angular blocky structure parting to weak fine and medium subangular blocky; friable; strongly effervescent; moderately alkaline; gradual wavy boundary.
Cg--165 to 200 centimeters; very dark gray (N 3/0) silty clay loam; massive; friable; strongly effervescent; moderately alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 107A-Iowa and Minnesota Loess Hills, Clay County, Iowa subset; about 3 miles northeast of Gillet Grove; located about 650 feet east and 700 feet south of the northwest corner of sec. 16, T. 95 N., R. 35 W.; USGS Silver Lake topographic quadrangle; lat. 43 degrees 03 minutes 05 seconds N. and long. 94 degrees 59 minutes 25 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--75 to more than 150 centimeters
Depth to carbonates--0 to 25 centimeters
Depth to gypsum and other salts--more than 200 centimeters
Clay content in the particle-size control section (weighted average)--24 to 35 percent
Sand content in the particle-size control section (weighted average)--1 to 15 percent
Ap or A horizon:
Hue--10YR, 5Y, or is neutral
Value--2, 2.5, or 3
Chroma--0 or 1
Texture--silt loam or silty clay loam
Clay content--24 to 35 percent
Sand content--1 to 15 percent
Reaction--pH 7.4 to 8.4
Thickness--more than 75 centimeters
Some pedons have subhorizons below a depth of 50 centimeters that are not effervescent and have a reaction range of pH 6.6 to 7.8
Some pedons have an AC horizon
Bg or BCg (when present) horizons:
Hue--10YR, 2.5Y, 5Y, or is neutral
Value--3 to 6
Chroma--0 to 2
Texture--silt loam or silty clay loam
Clay content--24 to 35 percent
Sand content--1 to 15 percent
Reaction--pH 7.4 to 8.4
Thickness--25 to 60 centimeters
Cg horizon:
Hue--10YR, 2.5Y, 5Y, or is neutral
Value--3 to 6
Chroma--0 to 3
Texture--silty clay loam, silt loam, or loam
Clay content--24 to 35 percent
Sand content--1 to 35 percent
Reaction--pH 7.4 to 8.4
Some pedons have strata in the Cg horizon that have more clay or more sand
Some pedons have an Ab horizon
COMPETING SERIES: These are the
Badus,
Devilsgait,
Lamo,
Obert,
Salmo,
Sawabash, and
Wingdale series.
Badus--have accumulations of gypsum and other salts within a depth of 150 centimeters
Devilsgate--do not have cambic horizons
Lamo--have a frequently saturated zone at a depth of 0.45 meter during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Obert--are in areas that have a mean annual precipitation range of 550 to 690 millimeters
Salmo--have segregated nests and crystals of gypsum in the upper two-thirds of the series control section
Sawabash--are in areas that have a mean annual precipitation range of 864 to 1,016 millimeters
Wingdale--are in areas that have a mean annual precipitation range of 230 to 360 millimeters and have layers in the upper third of the series control section that have been influenced by volcanic ash deposition
GEOGRAPHIC SETTING:
Parent material--calcareous alluvium
Landform--floodplains in river valleys
Slope--0 to 2 percent
Elevation--130 to 500 meters above sea level
Mean annual air temperature--4 to 13 degrees C
Mean annual precipitation--690 to 864 millimeters
Frost-free period--140 to 215 days
GEOGRAPHICALLY ASSOCIATED SOILS: Near the type location these are the
Colo,
Klossner, and
Terril soils.
Colo--are in landscape positions similar to those of the Calco soils and do not have carbonates within a depth of 150 centimeters
Klossner--are in lower landscape positions in slight depressions and have a histic epipedon
Terril--are on higher landscape positions on footslopes of uplands and do have a frequently saturated zone within depths of 1 to 1.8 meters 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--very poorly drained and poorly drained--these soils are frequently saturated at the surface of the soil 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, this saturation is considered apparent
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Ponding--very poorly drained phase has ponding up to 0.3 meter for long duration during late winter and spring of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation and after heavy precipitation events
Flooding--rarely flooded to frequently flooded for very brief to long duration
USE AND VEGETATION:
Most undrained areas are pastured. Areas that are artificially drained are cultivated. The principle crops are corn, soybeans, and small grains. The native vegetation is prairie cordgrass, reedgrass, sedges, big bluestem, little bluestem and other grasses of the tall grass prairie that are tolerant of excessive wetness.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Western lake section, Wisconsin driftless section, Till plains, and Dissected till plains
MLRAs--Rolling Till Prairie (102A),
Till Plains (102B),
Loess Uplands (102C),
Central Iowa and Minnesota Till Prairies (103),
Eastern Iowa and Minnesota Till Prairies (104),
Northern Mississippi Valley Loess Hills (105),
Nebraska and Kansas Loess-Drift Hills (106),
Iowa and Missouri Deep Loess Hills (107),
Illinois and Iowa Deep Loess and Drift (108), and
Central Mississippi Valley Wooded Slopes (115)
LRR M; Iowa, southern Minnesota, eastern Nebraska, northeastern Kansas, southeast South Dakota, and Illinois
Extent--large
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota; MLRA SSO 10-6 (Atlantic, Iowa)
SERIES ESTABLISHED: Cass County, Iowa 1967.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.
Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 165 centimeters (Ap, A1, A2, A3, A4, and Bg horizons);
cambic horizon--the zone from a depth of 127 to 165 centimeters (Bg horizon);
aquic moisture regime.
Cation-exchange class is inferred from lab data for similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
In relocation of the Calco OSD site from Cass County to Clay County, an error was discovered in the latitude and longitude coordinates of the Calco taxonomic site in Clay County, Iowa. The latitude and longitude coordinates of the type location in this revision are the corrected values.