LOCATION CORLEY                  IA

Established Series
Rev. JRN-RAL-RJB
06/2015

CORLEY SERIES

The Corley series consists of very deep, poorly drained, moderately permeable soils formed in loess in depressions on uplands and high stream benches. Slopes range from 0 to 2 percent. Mean annual air temperature is about 50 degrees F. Mean annual precipitation is about 29 inches.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Argiaquic Argialbolls

TYPICAL PEDON: Corley silt loam, on a concave slope of less than 1 percent, in a cultivated field, at an elevation of 1,000 feet above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 10 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; moderate medium granular structure; friable; strongly acid; clear smooth boundary.

A--10 to 18 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; moderate fine subangular blocky structure parting to weak fine granular; friable; strongly acid; clear smooth boundary. (Combined thickness of the A horizon is 8 to 20 inches.)

E--18 to 29 inches; dark gray (10YR 4/1) silt loam, light gray (10YR 7/1) dry; weak thick platy structure; friable; strongly acid; clear smooth boundary. (6 to 12 inches thick)

Bt--29 to 36 inches; very dark gray (10YR 3/1) silt loam, dark gray (10YR 4/1) dry; moderate medium prismatic structure parting to moderate medium subangular blocky; friable; many distinct clay films on faces of peds; strongly acid; clear smooth boundary. (6 to 10 inches thick)

Btg1--36 to 47 inches; dark gray (5Y 4/1) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; many distinct clay films on faces of peds; dark stains along root channels; moderately acid; gradual smooth boundary.

Btg2--47 to 60 inches; dark gray (5Y 4/1) silty clay loam; weak coarse prismatic structure parting to weak medium subangular blocky; firm; many distinct clay films on faces of peds; dark organic stains along root channels; few fine prominent light olive brown (2.5Y 5/6) redoximorphic concentrations; slightly acid; gradual smooth boundary. (Combined thickness of the Btg horizon is 20 to 28 inches.)

Cg--60 to 68 inches; olive gray (5Y 5/2) silt loam; massive; friable; few fine prominent light olive brown (2.5Y 5/6) redoximorphic concentrations; neutral.

TYPE LOCATION: Mills County, Iowa; about 2 miles east and 1 mile south of Malvern; about 1,750 feet east and 300 feet north of the southwest corner of sec. 34, T. 72 N., R. 41 W.; USGS Tabor NE quadrangle; lat. 40 degrees 59 minutes 24 seconds N. and long. 95 degrees 33 minutes 9 seconds W., NAD 27

RANGE IN CHARACTERISTICS:
Depth to argillic horizon--14 to 32 inches
Depth to carbonates--more than 60 inches
Content of clay in the particle-size control section (weighted average)--26 to 32 percent
Content of sand in the particle-size control section (weighted average)--less than 5 percent fine sand and sand coarser than fine sand

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1
Texture--silt loam
Clay content--20 to 27 percent
Sand content--5 percent or less
Reaction--strongly acid to neutral

E horizon:
Hue--10YR
Value--4 or 5
Chroma--1 or 2
Texture--silt loam
Clay content--20 to 24 percent
Sand content--5 percent or less
Reaction--strongly acid to neutral

Bt horizon:
Hue--10YR, 5Y, or neutral
Value--2 or 3
Chroma--0 or 1
Texture--silt loam or silty clay loam
Clay content--27 to 32 percent
Sand content--5 percent or less
Reaction--strongly acid to slightly acid

Btg horizon:
Hue--10YR to 5Y
Value--4 to 6
Chroma--1 or 2
Texture--silty clay loam
Clay content--28 to 32 percent (thin subhorizons may contain as much as 34 percent clay)
Sand content--5 percent or less
Reaction--strongly acid to slightly acid

Some pedons have a BCg horizon

Cg horizon:
Hue--2.5Y or 5Y
Value--5 or 6
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--24 to 28 percent
Sand content--5 percent or less
Reaction--moderately acid to neutral

COMPETING SERIES: These are the Ebbert, Edgington, Knight, Marissa, Normal, Speed, Thorp, and Vesser series.
Ebbert--have color values of more than 3 in the upper part of the argillic horizon
Edgington--have color values of more than 3 in the upper part of the argillic horizon
Knight--have more than 5 percent sand in the lower part of the series control section
Marissa--have carbonates within a depth of 40 to 60 inches
Normal--do not have aquic conditions with matrix color of 2 chroma or less in one or more horizons in the series control section
Speed--have more than 5 percent sand in the particle-size control section
Thorp--have 15 to 75 percent sand in the lower part of the series control section
Vesser--have 10 to 20 percent sand in the particle-size control section

GEOGRAPHIC SETTING:
Parent material--loess
Landform--closed depressions on upland divides and stream terraces
Slopes--0 to 2 percent
Elevation--800 to 1,500 feet above sea level
Mean annual air temperature--48 to 53 degrees F.
Mean annual precipitation--26 to 33 inches
Frost-free period--145 to 175 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Marshall, Minden, and Monona soils.
Marshall--are at the lower landscape positions or at the slightly higher landscape positions, do not have eluvial horizons, and do not have a seasonally saturated zone within a depth of 6 feet
Minden--are at the slightly higher landscape positions, do not have eluvial horizons, and have a seasonally saturated zone within a depth of 1 to 3 feet
Monona--are at the lower landscape positions or at the slightly higher landscape positions, do not have eluvial horizons, and do not have a seasonally saturated zone within a depth of 6 feet

DRAINAGE AND PERMEABILITY:
Drainage class--poorly drained--a saturated zone occurs within a depth of 1 foot during April to June in most years and is considered apparent
Permeability--moderate
Surface runoff potential--negligible
Ponding--unless artificially drained, these soil pond up to 1 foot of water above the surface for long periods during late winter and spring in most years and after heavy precipitation events

USE AND VEGETATION:
Where drained, these soils are cultivated. Principal crops are corn, legume hays, small grains, and soybeans. The native vegetative cover is a herbaceous wetland community commonly inhabited with Bluejoint Grasses, Fowl Bluegrasses, Green Muhlies, Fox Sedges, Field Sedges, Dudleys Rushes, Torreys Rushes, Swamp Milkweeds, False Sneezeweeds, False Asters, New England Asters, White Panicled Asters, and Wild Mints.

DISTRIBUTION AND EXTENT:
LRR= M, MLRA 107; western Iowa. This series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Shelby County, Iowa, 1958.

REMARKS:
Diagnostic horizons and features recognized in this pedon:
particle-size control section--the zone from a depth of 29 to 49 inches (Bt and Btg1 horizons);
series control section--the zone from the surface to a depth of 60 inches (Ap, A, E, Bt, Btg1, and Btg2 horizons);
mollic epipedon--the zone from the surface to a depth of 18 inches (Ap and A horizons);
albic horizon--the zone from a depth of 18 to 29 inches (E horizon);
argillic horizon--the zone from a depth of 29 to 60 inches (Bt, Btg1, and Btg2 horizons);
redoximorphic concentrations--in the zone from a depth of 47 to 68 inches (Btg2, C horizons);
aquic moisture regime.
Cation-exchange class is inferred from lab data for similar soils in the surrounding area.
Taxonomy version--Second Edition, 1999.

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National Cooperative Soil Survey
U.S.A.