LOCATION COPPOCK                 IA

Established Series
Rev. JAL-JWH-RJB
06/2015

COPPOCK SERIES

The Coppock series consists of very deep, poorly drained soils formed in silty alluvium. These soils are on treads and risers on stream terraces, foot slopes, and alluvial fans. Slope ranges from 0 to 5 percent. Mean annual air temperature is about 9 degrees C. Mean annual precipitation is about 900 millimeters.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Endoaqualfs

TYPICAL PEDON: Coppock silt loam, on a linear to slightly convex slope of about 1 percent, on a natural levee of an abandoned stream channel, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; moderately acid; abrupt smooth boundary. (15 to 25 centimeters thick)

E1--20 to 36 centimeters; dark grayish brown (10YR 4/2) and very dark grayish brown (10YR 3/2) silt loam, light brownish gray (10YR 6/2) dry; weak thin platy structure parting to weak fine granular; friable; few very dark grayish brown (10YR 3/2) coats on faces of peds; few fine dark brown (10YR 3/3) oxide coats; strongly acid; clear smooth boundary.

E2--36 to 51 centimeters; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak thin platy structure parting to weak fine granular blocky; friable; few faint light gray (10YR 7/2) dry, silt coats and few very dark grayish brown (10YR 3/2) coats on plates; few dark reddish brown (5YR 3/3) oxide coats; very strongly acid; clear smooth boundary.

E3--51 to 64 centimeters; grayish brown (10YR 5/2) silt loam, light brownish gray (10YR 6/2) and light gray (10YR 7/2) dry; weak medium platy structure parting to weak fine subangular blocky; friable; few dark grayish brown (10YR 4/2) coats on faces of peds; common distinct light gray (10YR 7/2) silt coats on faces of peds; few fine reddish brown (5YR 4/3) oxide coats; extremely acid; clear wavy boundary. (Combined thickness of the E horizon is 35 to 62 centimeters.)

BE--64 to 81 centimeters; grayish brown (10YR 5/2) silt loam, light gray (10YR 7/2) dry; moderate medium subangular blocky structure; friable; common distinct light gray (10YR 7/2) dry, silt coats on faces of peds; few dark grayish brown (10YR 4/2) coats on faces of peds; common fine dark reddish brown (5YR 3/3) oxide coats; few fine distinct brown (7.5YR 4/4) redoximorphic concentrations; extremely acid; gradual smooth boundary. (0 to 20 centimeters thick)

Btg1--81 to 94 centimeters; grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silt loam; weak medium prismatic structure parting to moderate medium subangular blocky; friable; common distinct dark brown (10YR 3/3) clay films on faces of peds; common distinct light gray (10YR 7/2) silt coats on faces of peds; common fine reddish brown (5YR 4/3) oxide coats; common fine distinct brown (7.5YR 4/4) redoximorphic concentrations; extremely acid; gradual smooth boundary.

Btg2--94 to 109 centimeters; grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silty clay loam; moderate medium prismatic structure parting to weak medium subangular blocky; friable; common distinct dark brown (10YR 3/3) clay films on faces of peds; many distinct light gray (10YR 7/1) silt coats on faces of peds; common fine dark reddish brown (5YR 3/3) oxide coats; common fine and medium prominent reddish brown (5YR 4/4) and yellowish red (5YR 4/6) redoximorphic concentrations; extremely acid; gradual smooth boundary.

Btg3--109 to 135 centimeters; grayish brown (10YR 5/2) silty clay loam; weak medium prismatic structure; friable; few distinct dark gray (10YR 4/1) clay films on faces of peds; few distinct light gray (10YR 7/1) silt coats on faces of peds; common fine dark reddish brown (5YR 3/3) oxide coats; common fine and medium prominent reddish brown (5YR 4/4) and strong brown (7.5YR 5/6) redoximorphic concentrations; very strongly acid; clear smooth boundary.

Btg4--135 to 160 centimeters; dark brown (7.5YR 3/2) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; friable; few distinct dark gray (10YR 4/1) clay films on surfaces along root channels and pores; grayish brown (10YR 5/2) coats on faces of peds; few dark reddish brown (5YR 3/2) oxide coats; few fine faint brown (7.5YR 4/4) redoximorphic concentrations; very strongly acid; gradual smooth boundary. (Combined thickness of the Btg horizon is 25 to 100 centimeters.)

BCg--160 to 191 centimeters; very dark grayish brown (10YR 3/2) silty clay loam; weak fine and medium subangular blocky structure; friable; very dark gray (10YR 3/1) coats on faces of peds; few distinct light gray (10YR 7/1) dry, silt coats on faces of peds; few fine distinct dark yellowish brown (10YR 4/4) redoximorphic concentrations; few fine distinct light brownish gray (10YR 6/2) redoximorphic depletions; strongly acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 109-Iowa and Missouri Heavy Till Plain, Appanoose County, Iowa subset; about 5 miles east and 6 miles south of Centerville; located about 600 feet east and 910 feet north of the southwest corner of section 25, T. 68 N., R. 17 W.; USGS Centerville East topographic quadrangle; lat. 40 degrees 39 minutes 19 seconds N. and long. 92 degrees 46 minutes 12 seconds W., NAD83.

RANGE IN CHARACTERISTICS:
Depth to carbonates--more than 150 centimeters
Depth to argillic horizon--50 to 100 centimeters
Clay content in the particle-size control section (weighted average)--27 to 35 percent
Sand content in the particle-size control section (weighted average)--2 to 15 percent
Rock fragment content--0 percent

A or Ap horizon:
Hue--10YR
Value--3
Chroma--1 or 2
Texture--silt loam
Clay content--15 to 25 percent
Sand content--5 to 15 percent
Reaction--moderately acid to neutral

E horizon:
Hue--10YR
Value--4 to 6
Chroma--1 or 2
Texture--silt loam
Clay content--15 to 25 percent
Sand content--5 to 15 percent
Reaction--extremely acid to neutral

BE horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2
Texture--silt loam or silty clay loam
Clay content--18 to 28 percent
Sand content--2 to 15 percent
Reaction--extremely acid to slightly acid

Btg and BCg horizons:
Hue--7.5YR, 10YR or 2.5Y
Value--3 to 6
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--25 to 38 percent
Sand content--2 to 15 percent
Reaction--extremely acid to moderately acid

The layer of maximum clay content occurs below a depth of 75 centimeters in most pedons

Some pedons have sandy materials below a depth of 150 centimeters

COMPETING SERIES: These are the Ansgar, Blanchester, Cory, Newberry, and Walford series.
Ansgar--have a sand content of 35 to 50 percent in the lower third of the series control section
Blanchester--have a rock fragment content of 2 to 10 percent in the lower third of the series control section
Cory--are in areas with a mean annual air temperature range of 11 to 13 degrees C and a mean annual precipitation range of 1,016 to 1,118 millimeters and have albic horizons 18 to 48 centimeters thick
Newberry--have a sand content that averages 15 to 40 percent in the lower third of the series control section
Walford--have a clay content of 18 to 27 percent in the lower third of the series control section, a sand content of 5 to 20 percent in the lower third of the series control section, and have albic horizons 8 to 25 centimeters thick

GEOGRAPHIC SETTING:
Parent material--silty alluvium
Landform--treads and risers on stream terraces, foot slopes, and alluvial fans
Slope--0 to 5 percent
Elevation--155 to 400 meters above sea level
Mean annual air temperature--6 to 12 degrees C
Mean annual precipitation--760 to 1,040 millimeters
Frost-free period--145 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amana, Carlow, Chequest, and Nodaway soils.
Amana--are at slightly lower landscape positions on floodplains and do not have an albic horizon
Carlow--are at slightly lower landscape positions on floodplains and have a clay content that averages 45 to 60 percent in the particle-size control section
Chequest--are at slightly lower landscape positions on floodplains and have a clay content that averages 35 to 42 percent in the particle-size control section
Nodaway--are on landscape positions similar to those of the Coppock soils and do not have an argillic horizon

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained--these soils are frequently saturated at the soil surface during the wettest periods of normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Surface runoff potential--negligible or low
Flooding--rarely flooded to frequently flooded for brief to long duration

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and hay. A few areas are in permanent pasture. The native vegetative cover is a mixed herbaceous and woody community commonly inhabited with Green Ashes, American Elms, Common Hackberries, Eastern Cottonwoods, American Sycamores, Silky Dogwoods, Black Willows, Wild Black Currants, Riverbank Grapes, Grays Sedges, Hop Sedges, Virginia Wildryes, Stiff Bedstraws, White Avens, Wood Nettles, False Nettles, Canadian Clearweeds, and Common Bonesets.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains and Wisconsin driftless section
MLRAs--Northern Mississippi Valley Loess Hills (105), Illinois and Iowa Deep Loess and Drift, West-Central Part (108C), and Iowa and Missouri Heavy Till Plain (109)
LRR M; southern and southeastern Iowa
Extent--moderate

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

SERIES ESTABLISHED: Jefferson County, Iowa, 1957.

REMARKS:
Particle-size control section--the zone from a depth of 81 to 131 centimeters;
series control section--the zone from the surface to a depth of 160 centimeters.

Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 81 centimeters (Ap, E1, E2, E3, and BE horizons);
albic horizon--the zone from a depth of 20 to 81 centimeters (E1, E2, E3, and BE horizons);
argillic horizon--the zone from a depth of 81 to 160 centimeters (Btg1, Btg2, Btg3, and Btg4 horizons);
aquic moisture regime.

Water table depths have been updated by agreement by the MLRA 108 steering committee on water table depths and drainage class, 4/98.

Cation-exchange activity class is supported by lab data from National Soil Survey Laboratory, Lincoln, Nebraska.

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska--User Pedon ID 71IA007001 (http://ssldata.sc.egov.usda.gov/).

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National Cooperative Soil Survey
U.S.A.