LOCATION GRANTCENTER             IA

Established Series
Rev. BCJ-RAL-TWN
04/2024

GRANTCENTER SERIES

The Grantcenter series consists of very deep, somewhat poorly drained soils on old stream meanders and natural levees on flood plains. These soils formed in medium to moderately fine textured alluvium. Slopes range from 0 to 2 percent. Mean annual air temperature is about 48 degrees C. Mean annual precipitation is about 675 millimeters.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Hapludolls

TYPICAL PEDON: Grantcenter silty clay loam, on a l percent slope, in a cultivated field, at an elevation of 323 meters above sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 centimeters; black (10YR 2/1) silty clay loam; dark gray (10YR 4/1) dry; weak very fine and fine granular structure; friable; few very fine roots; slightly acid; abrupt smooth boundary.

A--15 to 36 centimeters; black (10YR 2/1) silty clay loam; dark gray (10YR 4/1) dry; weak very fine and fine subangular blocky structure parting to weak very fine and fine granular; friable; few very fine roots; neutral; clear smooth boundary. (Combined thickness of the A horizon is 25 to 60 centimeters.)

AB--36 to 58 centimeters; very dark grayish brown (2.5Y 3/2) silty clay loam; grayish brown (2.5Y 5/2) dry; weak very fine and fine subangular blocky structure; friable; few very fine roots; black (10YR 2/1) organic coats on faces of peds; common fine and medium rounded worm casts; few fine distinct dark yellowish brown (10YR 3/4) redoximorphic concentrations; neutral; gradual smooth boundary. (0 to 25 centimeters thick)

Bg1--58 to 81 centimeters; dark grayish brown (2.5Y 4/2) silt loam; weak fine and medium subangular blocky structure; friable; few very fine roots; very dark grayish brown (2.5Y 3/2) organic coats on faces of peds; common fine and medium rounded worm casts; common fine distinct dark yellowish brown (10YR 3/4) and prominent dark brown (7.5YR 3/4) redoximorphic concentrations; neutral; gradual smooth boundary.

Bg2--81 to 112 centimeters; dark grayish brown (2.5Y 4/2) silt loam; weak fine and medium subangular blocky structure; friable; few very fine roots; very dark grayish brown (2.5Y 3/2) organic coats on faces of peds; common fine and medium rounded worm casts; common fine prominent dark brown (7.5YR 3/4) and common fine distinct dark yellowish brown (10YR 3/4) redoximorphic concentrations; slightly alkaline; gradual smooth boundary.

Bg3--112 to 127 centimeters; dark grayish brown (2.5Y 4/2) and grayish brown (2.5Y 5/2) silt loam; weak medium subangular blocky structure; friable; few very fine roots; common fine and medium rounded worm casts; common fine prominent dark brown (7.5YR 3/4) and common fine distinct dark yellowish brown (10YR 3/4) redoximorphic concentrations; slightly alkaline; gradual smooth boundary. (Combined thickness of the Bg horizon is 20 to 102 centimeters.)

BCg--127 to 142 centimeters; dark grayish brown (2.5Y 4/2) and grayish brown (2.5Y 5/2) silt loam; weak medium subangular blocky structure; friable; few very fine roots; common medium rounded worm casts; few fine prominent dark brown (7.5YR 3/4) and few fine distinct dark yellowish brown (10YR 3/4) redoximorphic concentrations; slightly alkaline; gradual smooth boundary. (0 to 25 centimeters thick)

Cg--142 to 203 centimeters; dark grayish brown (2.5Y 4/2) and grayish brown (2.5Y 5/2) silt loam; massive; friable; common fine and medium rounded worm casts; few fine prominent dark brown (7.5YR 3/4) and few fine distinct dark yellowish brown (10YR 3/4) redoximorphic concentrations; very slightly effervescent; slightly alkaline.

TYPE LOCATION: Major Land Resource Area (MLRA) 107B-Iowa and Missouri Deep Loess Hills; Monona County, Iowa subset; about 1,400 feet south and 1,200 feet west of the northeast corner of section 16, T. 85 N., R. 44 W.; USGS Onawa topographic quadrangle; lat. 42 degrees 7 minutes 15 seconds N. and long. 96 degrees 0 minutes 18 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to carbonates--60 to 150 centimeters
Thickness of the mollic epipedon--25 to 60 centimeters
Content of clay in the particle-size control section (weighted average)--18 to 35 percent
Content of sand in the particle-size control section (weighted average)--8 to 15 percent fine sand or sand coarser than fine sand
Rock fragment content--0 percent

A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silty clay loam or silt loam
Clay content--24 to 39 percent
Sand content--10 to 25 percent
Reaction--moderately acid to neutral

AB horizon:
Hue--10YR or 2.5Y
Value--3
Chroma--2
Texture--silt loam or silty clay loam
Clay content--18 to 30 percent
Sand content--8 to 15 percent fine sand or sand coarser than fine sand
Reaction--slightly acid or neutral

Bg horizon:
Hue--10YR or 2.5Y
Value--3 to 5
Chroma--2
Texture--silt loam or silty clay loam
Clay content--15 to 39 percent
Sand content--8 to 15 percent fine sand or sand coarser than fine sand
Reaction--neutral or slightly alkaline

Bk or Bkg horizon (if it occurs):
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silt loam or silty clay loam
Clay content--15 to 30 percent
Sand content--15 to 40 percent
Reaction--slightly alkaline or moderately alkaline

BCg horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silt loam
Clay content--10 to 25 percent
Sand content--15 to 40 percent
Reaction--slightly alkaline or moderately alkaline

Some pedons have sandy loam layers below a depth of 40 inches

C or Cg horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 4
Texture--silt loam, loam, or stratified loam and silt loam
Clay content--10 to 25 percent
Sand content--15 to 50 percent
Reaction--slightly alkaline or moderately alkaline
Moist bulk density--1.3 g/cc to 1.4 g/cc

COMPETING SERIES: These are the Amana, Breeds, Joy, Joyce, Kingston, Klinger, Klingmore, Lakefield, Larpenteur, McCreath, Minden, Muscatine, Nerwoods, Okabena, Primghar, and Ransom series.
Amana--do not have carbonates within a depth of 150 centimeters and have a variable coarse silt to fine silt ratio in the series control section
Breeds--have a shale paralithic contact within a depth of 150 centimeters
Joy--have less than 10 percent sand coarser than very fine sand in the lower third of the series control section
Joyce--have more than 70 percent sand in the lower third of the series control section
Kingston--have less than 8 percent fine sand or sand coarser than fine sand in the particle-size control section
Klinger--have a moist bulk density range of 1.8 g/cc to 2.0 g/cc in the lower two thirds of the series control section
Klingmore--have a moist bulk density range of 1.8 g/cc to 2.0 g/cc in the lower third of the series control section
Lakefield--have carbonates within a depth of 25 centimeters and have a sand content of less than 15 percent fine sand and sand coarser than fine sand in the lower half of the series control section
Larpenteur--have carbonates within a depth of 25 centimeters and have a sand content of 15 to 55 percent fine sand and sand coarser than fine sand in the lower half of the series control section
McCreath--have moist bulk density range of 1.6 g/cc to 1.8 g/cc in the lower third of the series control section
Minden--do not have carbonates within a depth of 150 centimeters and have a sand content of less than 10 percent throughout the series control section
Muscatine--have carbonates within a depth of 120 centimeters and have less than 5 percent sand in the particle-size control section
Nerwoods--have carbonates between depths of 100 to 200 centimeters and have a sand content of more than 15 percent in the upper third of the series control section
Okabena--have carbonates between depths of 50 to 100 centimeters and have 2 to 8 percent rock fragments in the lower third of the series control section
Primghar--have less than 3 percent sand throughout the particle-size control section
Ransom--have carbonates between depths of 56 to 100 centimeters and have 2 to 8 percent rock fragments in the lower half of the series control section

GEOGRAPHIC SETTING:
Parent material--medium to moderately fine textured alluvium
Landform--old stream meanders and natural levees on flood plains
Slopes--0 to 2 percent
Elevation--213 to 366 meters above sea level
Mean annual air temperature--7 to 10 degrees C
Mean annual precipitation--600 to 750 millimeters
Frost-free period--140 to 160 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blencoe, Colo, Kennebec, Lakeport, Larpenteur, and McPaul soils.
Blencoe--are in landform positions similar to those of the Grantcenter soils and have 40 to 52 percent clay in the upper two thirds of the particle-size control section
Colo--are in the lower landscape positions, have a saturated zone within a depth of 0.3 meter in normal years and have a mollic epipedon that is more than 60 centimeters thick
Kennebec--are in landform positions similar to those of the Grantcenter soils or in the slightly higher landscape positions, have a saturated zone within depths of 0.9 meter in normal years and have a mollic epipedon that is more than 60 centimeters thick
Lakeport--are in landform positions similar to those of the Grantcenter soils and have 35 to 45 percent clay in the particle-size control section
Larpenteur--are in landform positions similar to those of the Grantcenter soils and have carbonates within a depth of 25 centimeters
McPaul--are at the slightly higher elevations, do not have a mollic epipedon, and have carbonates within a depth of 25 centimeters

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a saturated zone occurs within depths of 0.3 meter during April to June in normal years and is considered apparent
Saturated hydraulic conductivity--4.23 to 14.11 micrometers per second (moderately high)
Surface runoff potential--negligible or low
Flooding--rare or occasional flooding for brief periods during the months of February to November resulting from precipitation events and snowmelt

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans and small grains. The native vegetation is big bluestem, indiangrass, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRA--Iowa and Missouri Deep Loess Hills (107B)
LRR M--flood plains of the Missouri River in Iowa and possibly in Missouri, Nebraska and South Dakota
Extent--small

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Monona County, 1995.

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (A, AB, Bg1, and Bg2 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (A, AB, 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 58 centimeters (Ap, A, and AB horizons);
cambic horizon--the zone from a depth of 58 to 142 centimeters (Bg and BCg horizons);
udic moisture regime.

Cation-exchange class is inferred from lab data for similar soils in the surrounding area.

Taxonomy version--Keys to Soil Taxonomy, ninth edition, 2003.

Grantcenter soil was formerly included in the Kennebec and Colo series. They are not frequently saturated to the surface in normal years.

ADDITIONAL DATA:
Refer to Iowa State University Agriculture Experiment Station file 54321-54328.

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National Cooperative Soil Survey
U.S.A.