LOCATION DOW IA+NEEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Typic Udorthents
TYPICAL PEDON: Dow silt loam, on an east-facing, convex slope of 11 percent, in a cultivated field, at an elevation of about 419 meters above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 15 centimeters; brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak medium subangular blocky structure parting to weak fine granular; friable; common fine and very fine roots; few fine and very fine pores; slightly effervescent; moderately alkaline; clear smooth boundary. (10 to 25 centimeters thick)
C1--15 to 38 centimeters; grayish brown (2.5Y 5/2) silt loam; massive with weak coarse stratification; very friable; common fine and very fine roots; few fine and very fine pores; few distinct brown (10YR 4/3) organic stains along lamina or strata surfaces; few fine and medium prominent yellowish brown (10YR 5/6) and few fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; strongly effervescent; moderately alkaline; gradual smooth boundary. (15 to 40 centimeters thick)
C2--38 to 53 centimeters; light brownish gray (2.5Y 6/2) silt loam; massive; very friable; few very fine roots; few very fine pores; few fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; strongly effervescent; moderately alkaline.
C3--53 to 200 centimeters; light brownish gray (2.5Y 6/2) silt loam; massive; very friable; few very fine pores; few fine prominent strong brown (7.5YR 5/6) and reddish brown (5YR 4/4) redoximorphic concentrations; strongly effervescent; moderately alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 107B-Iowa and Missouri Deep Loess Hills, Crawford County, Iowa subset; about 4 miles south and 2 miles west of Dow City; located about 2,525 feet north and 410 feet west of the southeast corner of section 31, T. 82 N., R. 40 W.; USGS Dunlap NE topographic quadrangle; lat. 41 degrees 52 minutes 13.6 seconds N. and long. 95 degrees 32 minutes 22.0 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--less than 25 centimeters
Content of clay in the particle-size control section (weighted average)--18 to 25 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 horizon:
Hue--10YR
Value--3 to 5
Chroma--2 or 3
Texture--silt loam
Clay content--18 to 25 percent
Sand--less than 5 percent
Reaction--neutral to moderately alkaline
A horizon:
Hue--10YR
Value--2 or 3
Chroma--2
Texture--silt loam
Clay content--18 to 25 percent
Sand--less than 5 percent
Reaction--neutral to moderately alkaline
C horizon:
Hue--10YR to 5Y
Value--5 or 6
Chroma--2
Texture--silt loam
Clay content--18 to 25 percent, decreases regularly with depth, some pedons have a clay content of 15 percent below a depth of 1 meter
Sand content--less than 5 percent
Reaction--slightly alkaline or moderately alkaline
Calcium carbonate equivalent--8 to 12 percent
Redoximorphic features are considered relict and include high chroma concentrations, pipestems, or concretions high in iron
COMPETING SERIES: This is the
Ida series.
Ida--have a matrix chroma greater than 2 in the lower two thirds of the series control section
GEOGRAPHIC SETTING:
Parent material--loess
Landform--convex side slopes, summits and saddles of interfluves on dissected till plains
Slope--5 to 30 percent
Elevation--185 to 475 meters above sea level
Mean annual air temperature--8 to 13 degrees C
Mean annual precipitation--660 to 1,040 millimeters
Frost-free period--155 to 220 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Exira,
Ida,
Knox,
Marshall, and
Monona soils.
Exira--are in similar landscape positions to those of the Dow soils, have a cambic horizon, and do not have carbonates within a depth of 100 centimeters
Ida--are in similar landscape positions to those of the Dow soils and do not have a gray colored matrix in the lower two thirds of the series control section
Knox--are on higher landscape positions on convex slopes, have an argillic horizon, and do not have matrix chroma of 2 in the lower half of the series control section
Marshall--are on higher landscape positions on convex slopes, have a cambic horizon, and do not have carbonates within a depth of 180 centimeters
Monona--are on higher landscape positions on convex slopes, have a cambic horizon, and have carbonates within a depth of 180 centimeters
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a frequently saturated zone does not occur within a depth of 1.8 meters during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saturated hydraulic conductivity--1.0 to 10.0 micrometers per second
USE AND VEGETATION:
Gently sloping areas are cultivated. The principal crops are corn, hay, small grains, and soybeans. Steeply sloping areas are used for hay or pasture. The native vegetation is big bluestem, little bluestem, sideoats grama, indiangrass, switchgrass, and other grasses of the short grass and 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; western and northeastern Iowa, and southeastern Nebraska
Extent--small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Shelby County, Iowa, 1958.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (C1, C2, and C3 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, C1, C2, and C3 horizons).
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface to a depth of 15 centimeters (Ap horizon);
udic moisture regime.
Cation-exchange class is inferred from lab data for similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
Refer to DMUid 242,075 in NASIS for property data.
The gray and strong brown redoximorphic features in this pedon are believed to be relict and were not considered as indicators of current wetness conditions. These features were not considered in the classification of these soils.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska; user pedonid S97IA04701L (http://ssldata.sc.egov.usda.gov/).