LOCATION MT. STERLING IA

Established Series
Rev JAL-LEB-RJB
06/2015

MT. STERLING SERIES

The Mt. Sterling series consists of very deep, poorly drained soils formed in alluvium. These soils are on flood plains or alluvial fans in river valleys. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 940 millimeters. Mean annual air temperature is about 10 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Aeric Fluvaquents

TYPICAL PEDON: Mt. Sterling silt loam, on a nearly level bottom land, in grass, at an elevation of about 198 meters above mean seal level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 18 centimeters; grayish brown (10YR 5/2) and very dark grayish brown (10YR 3/2) silty clay loam, light gray (10YR 7/2) and grayish brown (10YR 5/2) dry; weak very fine and fine granular structure; friable; common fine roots; common distinct very dark gray (10YR 3/1) organic stains on all faces of peds; common fine faint brown (10YR 4/3) iron-manganese masses; neutral; abrupt smooth boundary. (12 to 25 centimeters thick)

Cg1--18 to 46 centimeters; grayish brown (10YR 5/2) and very dark grayish brown (10YR 3/2) and dark gray (10YR 4/1) silt loam; massive; friable; few fine roots; common fine distinct dark yellowish brown (10YR 4/4) iron-manganese masses; slightly acid; clear smooth boundary.

Cg2--46 to 61 centimeters; very dark grayish brown (10YR 3/2) and dark gray (10YR 4/1) and grayish brown (10YR 5/2) silty clay loam; massive; friable; few fine roots; common fine distinct dark yellowish brown (10YR 4/4) iron-manganese masses; slightly acid; clear smooth boundary. (Combined thickness of the Cg horizon is 25 to 90 centimeters.)

2Ab1--61 to 81 centimeters; very dark gray (10YR 3/1) silty clay; weak fine and medium subangular blocky structure; friable; few fine roots; common fine faint very dark grayish brown (10YR 3/2) and common fine prominent brown (7.5YR 4/4) iron-manganese masses; moderately acid; gradual smooth boundary.

2Ab2--81 to 112 centimeters; black (N 2/0) silty clay; weak fine and medium prismatic, and moderate very fine and fine subangular blocky structure; firm; few fine roots; common fine prominent brown (7.5YR 4/4) iron-manganese masses; very strongly acid; gradual smooth boundary.

2Ab3--112 to 137 centimeters; dark gray (10YR 4/1) and very dark gray (10YR 3/1) silty clay; weak medium prismatic structure; firm; few fine roots; common fine prominent strong brown (7.5YR 4/6) iron-manganese masses; very strongly acid; gradual smooth boundary. (Combined thickness of the 2Ab horizon is 50 to 100 centimeters.)

2Cg--137 to 200 centimeters; dark gray (10YR 4/1) silty clay; massive; firm; few fine roots; common fine prominent brown (7.5YR 4/4) and common fine distinct dark yellowish brown (10YR 4/4) iron-manganese masses; very strongly acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 109-Iowa and Missouri Heavy Till Plain, Van Buren County, Iowa subset; about 1 mile west and 1 mile north of Mount Sterling; located about 1,800 feet west and 200 feet north of the southeast corner of section 1, T. 67 N., R. 10 W.; USGS Mount Sterling topographic quadrangle; lat. 40 degrees 37 minutes 27 seconds N. and long. 91 degrees 57 minutes 17 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Depth to a buried horizon--50 to 100 centimeters
Depth to carbonates--more than 150 centimeters
Clay content in the particle-size control section (weighted average)--25 to 35 percent
Sand content in the particle-size control section (weighted average)--less than 5 percent

Ap or A (when present) horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--18 to 30 percent
Sand content--5 to 15 percent
Reaction--moderately acid to neutral

Cg or C (when present) horizon:
Hue--10YR
Value--2 to 6
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--18 to 30 percent
Sand content--5 to 15 percent
Reaction--moderately acid to neutral

2Ab horizon:
Hue--10YR or is neutral
Value--2 to 4
Chroma--0 or 1
Texture--silty clay loam or silty clay
Clay content--35 to 45 percent
Sand content--less than 10 percent
Reaction--very strongly acid to neutral

2C horizon:
Hue--10YR to 5Y
Value--4 to 6
Chroma--1 or 2
Texture--silty clay loam or silty clay
Clay content--35 to 48 percent
Sand content--less than 10 percent
Reaction--very strongly acid to slightly alkaline

COMPETING SERIES: This is the Woodinville series.
Woodinville--does not have a buried soil within the series control section

GEOGRAPHIC SETTING:
Parent material--alluvium
Landform--flood plains or alluvial fans in river valleys
Slope--0 to 5 percent
Elevation--155 to 460 meters above mean sea level
Mean annual air temperature--8 to 12 degrees C
Mean annual precipitation--840 to 1,040 millimeters
Frost-free period--170 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coppock, Nodaway, Vesser, and Wabash soils.
Coppock--are on landscape positions similar to those of the Mt. Sterling soils and have an albic horizon
Nodaway--are on slightly higher landscape positions typically closer to the stream channel and do not have a buried soil in the upper two thirds of the series control section
Vesser--are on landscape positions similar to those of the Mt. Sterling soils and have an albic horizon
Wabash--are on landscape positions similar to those of the Mt. Sterling soils and have a clay content that averages 45 to 60 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained--these soils are frequently saturated from the soil surface to a depth of 0.3 meter during the wettest period 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--1.0 to 10 micrometers per second in the upper materials and 0.1 to 1.0 micrometers per second in the buried materials
Flooding--rarely to frequently flooded for brief to long periods can occur in any month during the year due to precipitation events and snowmelt

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grain and forage. The native vegetative cover is a 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.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains
MLRAs--Illinois and Iowa Deep Loess and Drift, West-Central part (108C), Illinois and Iowa Deep Loess and Drift, Western part (108D), and Iowa and Missouri Heavy Till Plain (109)
LRR M; southeastern Iowa
Extent--small

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

SERIES ESTABLISHED: Van Buren County, Iowa 1994.

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:
ochric epipedon--the zone from the surface to a depth of 18 centimeters (Ap horizon);
aquic conditions--redoximorphic features present throughout the profile;
aquic soil moisture regime.

These soils have been placed in the Ackmore series in previous surveys.

Cation-exchange activity class is supported by NSSL data.

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

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory; Lincoln, Nebraska - user pedon ID 95IA177001 (http://ssldata.nrcs.usda.gov/).
Laboratory data--Iowa State University; Ames, IA - sample numbers 56922 through 56927.

National Cooperative Soil Survey
U.S.A.