LOCATION CALCO IA+IL KS MN NE SD

Established Series
Rev. RID-RAL-DJP
03/2020

CALCO SERIES

The Calco series consists of very deep, poorly drained and very poorly drained soils formed in calcareous alluvium. These soils are on flood plains in river valleys. Slope ranges from 0 to 2 percent. Mean annual air temperature is about 9 degrees C. Mean annual precipitation is about 775 millimeters.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Cumulic Endoaquolls

TYPICAL PEDON: Calco silty clay loam, on a 1 percent slope in a cultivated field on a flood plain, 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 distinct 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/) 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/) silty clay loam; massive; friable; strongly effervescent; moderately alkaline.

TYPE LOCATION: Land Resource Unit (LRU) 107A-Iowa and Minnesota Loess Hills; Clay County, Iowa; about 3 miles northeast of Gillet Grove; 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) horizon:
Hue--10YR to 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 to 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 in the lower part of the series control section.
Devilsgate--do not have a cambic horizon.
Lamo--are deeper than 0.3 meter to a frequently saturated zone during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation.
Obert--do not have a cambic horizon.
Salmo--have segregated nests and crystals of gypsum in the upper part of the series control section.
Sawabash--are in areas that have more than 864 millimeters of mean annual precipitation.
Wingdale--are in areas that have less than 690 millimeters of mean annual precipitation and have layers in the upper part of the series control section that have been influenced by volcanic ash deposition.

GEOGRAPHIC SETTING:
Parent material--calcareous alluvium
Landform--flood plains 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. See Additional Data section for native vegetative cover in Iowa, Minnesota, and Nebraska.

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 and LRUs--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 SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Cass County, Iowa 1967.

REMARKS:
Diagnostic horizons and features recognized in this pedon include:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (A1, A2, A3 horizons).
Series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, A3, Bg horizons).
Mollic epipedon--the zone from the surface to a depth of 127 centimeters (Ap, A1, A2, A3, A4 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, Twelfth Edition, 2014.

ADDITIONAL DATA: In Iowa and Minnesota, the native vegetative cover is an herbaceous wetland community commonly inhabited with Bluejoint Grasses, White Cutgrasses, Fox Sedges, Oval Sedges, Inland Rushes, Torreys Rushes, Dark Green Bulrushes, Flatstem Spikerushes, Blue Vervains, Indian Hemps, Winged Loosestrifes, Wild Mints, and Water Horehounds. Source: Iowa State Office, Natural Resources Conservation Service, Des Moines, IA.

In Nebraska, the native vegetative cover is an herbaceous wetland community commonly inhabited with sedges (Carex emoryi, C. laeviconica, C. pellita, C. vulpinoidea), flat stem spikerush, (Eleocharis compressa), Kentucky bluegrass (Poa Pratensis), prairie cordgrass (Spartina pectinate). Source: Terrestrial Ecological Systems and Natural Communities of Nebraska, Version IV. S.B. Rolfsmeier and G. Steinauer. Nebraska Natural Heritage Program, Nebraska Game and Parks Commission, 2010.

National Cooperative Soil Survey
U.S.A.