LOCATION MUNTERVILLE IA+ MOEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Oxyaquic Hapludalfs
TYPICAL PEDON: Munterville silt loam, on a north-facing slope of 19 percent, in a wooded pasture. (Colors are for moist soil unless otherwise stated.)
A--0 to 10 centimeters; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak very fine granular structure; friable; many fine roots; common distinct very dark gray (10YR 3/1) organic stains on faces of peds; slightly acid; clear smooth boundary.
E--10 to 20 centimeters; grayish brown (10YR 5/2) silt loam, light gray (10YR 7/2) dry; moderate medium platy structure; friable; many fine roots; few distinct very dark grayish brown (10YR 3/2) organic stains on horizontal faces of peds; slightly acid; clear smooth boundary.
Bt1--20 to 43 centimeters; brown (10YR 5/3) silty clay loam; moderate fine subangular blocky structure; friable; common roots; common distinct grayish brown (10YR 5/2) clay films on all faces of peds; few light gray (10YR 7/2), dry silt coats on all faces of peds; slightly acid; abrupt smooth boundary.
2Bt2--43 to 56 centimeters; light olive brown (2.5Y 5/3) silty clay; moderate medium subangular blocky structure; firm; common fine roots; common distinct dark grayish brown (2.5Y 4/2) clay films on all faces of peds; few light gray (10YR 7/2), dry silt coats on all faces of peds; common fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations; strongly acid; gradual smooth boundary.
2Bt3--56 to 86 centimeters; grayish brown (2.5Y 5/2) clay; weak medium angular blocky structure; firm; common fine roots; common distinct dark gray (2.5Y 4/1) clay films on all faces of peds; common fine prominent yellowish brown (10YR 5/6) redoximorphic concentrations;; strongly acid; gradual smooth boundary.
2BC--86 to 119 centimeters; gray (N 5/0) silty clay; weak medium prismatic structure; firm, common fine roots; few white (10YR 8/1) dry sand grains on vertical faces of peds; common fine prominent light olive brown (2.5Y 5/4) and yellowish brown (10YR 5/6) redoximorphic concentrations; strongly acid; gradual smooth boundary.
2C1--119 to 150 centimeters; dark gray (N 4/0) silty clay; weak medium platy rock structure inherited from shale; firm; few fine roots; few white (10YR 8/1) dry sand grains on surfaces of plates; common fine prominent light olive brown (2.5Y 5/4) redoximorphic concentrations; strongly acid; clear smooth boundary.
2C2--150 to 191 centimeters; light gray (5Y 7/1) silty clay; weak medium platy rock structure inherited from shale; firm; few fine roots; few white (10YR 8/1) dry sand grains on surfaces of plates; common medium prominent strong brown (7.5YR 5/8) redoximorphic concentrations; strongly acid; clear smooth boundary.
2Cr--191 to 200 centimeters; gray (5Y 6/1) silty clay laminated shale; massive with weak medium platy rock structure inherited from shale; very firm; common medium prominent yellowish brown (10YR 5/8) redoximorphic concentrations; strongly acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 109-Iowa and Missouri Heavy Till Plain, Wapello County, Iowa subset; about 3 miles east and 4 miles north of Blakesburg; located about 400 feet west and 1,800 feet south of the northeast corner of section 21, T. 72 N., R. 15 W.; USGS Chillicothe topographic quadrangle; lat. 41 degrees 01 minute 33.8 seconds N. and lat. 92 degrees 35 minutes 02.0 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to residuum--5 to 50 centimeters
Depth to silty clay shale paralithic contact--100 to 200 centimeters
Depth to carbonates--more than 200 centimeters
Clay content of the particle-size control section (weighted average)--36 to 58 percent
Sand content of the particle-size control section (weighted average)--less than 10 percent
A horizon:
Hue--10YR
Value--3 or 4
Chroma--2
Texture--loam, silt loam, or silty clay loam
Clay content--10 to 30 percent
Sand content--5 to 30 percent
Rock fragment content--0 to 10 percent
Reaction--pH 5.6 to 7.3
Thickness--8 to 13 centimeters
Ap horizon (when present):
Hue--10YR
Value--4
Chroma--2 or 3
Texture--loam, clay loam, silt loam, or silty clay loam
Clay content--15 to 35 percent
Sand content--5 to 30 percent
Rock fragment content--0 to 10 percent
Reaction--pH 5.6 to 7.3
Thickness--15 to 25 centimeters
E horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--silt loam or loam
Clay content--20 to 27 percent
Sand content--5 to 30 percent
Rock fragment content--0 to 10 percent
Reaction--pH 5.6 to 6.5
Thickness--0 to 20 centimeters
Where the soil is cultivated, the E horizon is partially or completely mixed into the Ap horizon
BE horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--2 to 4
Texture--silty clay loam or clay loam
Clay content--30 to 35
Sand content--10 to 30
Rock fragment content--0 to 10 percent
Reaction--pH 5.6 to 6.5
Thickness--0 to 20 centimeters
Bt horizon (when present):
Hue--10YR or 2.5Y
Value--5 or 6
Chroma--2 to 4
Texture--clay loam, silty clay loam or silty clay
Clay content--30 to 50 percent
Sand content--5 to 30 percent
Rock fragment content--0 to 10 percent
Reaction--pH 5.6 to 6.5
Thickness--0 to 30 centimeters
2Bt horizon:
Hue--10YR to 5Y, or is neutral
Value--5 or 6
Chroma--0 to 4
Texture--silty clay loam, silty clay, or clay
Clay content--35 to 65 percent
Sand content--0 to 20 percent
Rock fragment content--less than 15 percent, shale, limestone, sandstone, and lignite
Reaction--pH 3.5 to 6.5
Thickness--20 to 105 centimeters
2BC or 2C horizon:
Hue--10YR to 5Y, or is neutral
Value--3 to 7
Chroma--0 to 4
Texture--silty clay loam, silty clay, or clay
Clay content--30 to 65 percent
Sand content--0 to 20 percent
Rock fragment content--less than 15 percent, shale, limestone, sandstone, and lignite
Reaction--pH 3.5 to 6.5
Thickness--30 to 95 centimeters
2Cr horizon:
Hue--10YR to 5Y, or is neutral
Value--3 to 6
Chroma--0 to 6
Texture--silty clay loam, silty clay, clay, fissle shale, or lignite
Clay content--30 to 65 percent
Sand content--0 to 20 percent
Rock fragment content--less than 15 percent, shale, limestone, sandstone, and lignite
Base saturation--low
Reaction--pH 3.5 to 6.5
COMPETING SERIES: These are the
Aaron,
Alsup,
Brookside,
Derinda,
Ebal,
Goodson,
Miamian,
Morrisville,
Shircliff, Skraina,
Useful, and
Vincent series.
Aaron--have a lithic contact with limestone within a depth of 150 centimeters
Alsup--have more rock fragments in the series control section
Brookside--do not have a paralithic contact within 2 meters of the surface
Derinda--have a paralithic contact with shale within a depth of 100 centimeters
Ebal--have a sand content that averages 10 to 25 percent in the particle-size control section
Goodson--have a reaction range of pH 7.3 to 8.4 in the lower third of the series control section
Miamian--have carbonates within a depth of 100 centimeters
Morrisville--have carbonates within a depth of 75 centimeters
Shircliff--have carbonates within a depth of 150 centimeters
Skrainka--do not have a paralithic contact within a depth of 200 centimeters
Useful--have a lithic contact with dolomite within a depth of 150 centimeters
Vincent--do not have a paralithic contact within a depth of 200 centimeters
GEOGRAPHIC SETTING:
Parent material--5 to 50 centimeters of silty or loamy materials and in the underlying residuum from brown and gray acid Pennsylvanian shale
Landform--convex side slopes and escarpment-like areas that parallel major streams
Slope--5 to 40 percent
Elevation--100 to 505 meters above sea level
Mean annual air temperature--7 to 14 degrees C
Mean annual precipitation--660 to 1,270 millimeters
Frost-free period--145 to 230 days
GEOGRAPHICALLY ASSOCIATED SOILS: Members of the typical catena include
Keswick,
Lindley, and
Nodaway soils.
Keswick--are on higher landscape positions on side slopes and have sand content that averages 20 to 45 percent in the particle-size control section
Lindley--are on higher landscape positions on side slopes and have sand content that averages more than 20 percent in the particle-size control section
Nodaway--are on lower landscape positions on floodplains and have a clay content that averages 18 to 35 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs between depths of 0.6 and 1 meter during the wettest periods of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation, this saturated zone is considered perched
Saturated hydraulic conductivity--0.10 to 1.00 micrometers per second in the loamy or silty materials, and 0.01 to 0.10 micrometers per second in the residuum and paralithic material
USE AND VEGETATION:
Most areas are pastured and/or forested. The native vegetation is deciduous trees, dominantly hickory and oak.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains, and Till plains
MLRAs--Illinois and Iowa Deep Loess and Drift, West-Central Part (108C),
Illinois and Iowa Deep Loess and Drift, Western part (108D),
Iowa and Missouri Heavy Till Plain (109), Central Mississippi Valley Wooded Slopes, Western part (115B)
LRR M--southern Iowa and northern Missouri
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota; MLRA SSO 10-12 (Fairfield, Iowa).
SERIES PROPOSED: Wapello County, Iowa, 2009.
REMARKS:
Particle-size control section--the zone from a depth of 20 to 70 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.
Diagnostic horizon and features recognized in this pedon include:
ochric epipedon--the zone from the surface of the soil to a depth of 20 centimeters (A and E horizons);
albic horizon--the zone from a depth of 10 to 20 centimeters (E horizon);
argillic horizon--the zone from a depth of 20 to 86 centimeters (Bt1, 2Bt2, and 2Bt3 horizons);
paralithic contact--the contact with clayey shale at a depth of 191 centimeters (2Cr horizon);
udic moisture regime.
The geological origin of the mantle is variable. It may be silty materials such as loess, or loamy sediments derived from till, and the underlying residuum from interbedded shale, limestone, lignite, or sandstone.
Drainage class is difficult to assess because of the color inherited from the shale.
The gray colors in the lower half of the series control section are inherited from the shale and were not considered in classification of the series. The extreme variation in the shale parent material raises the question as to family placement. However, available data indicate that the clay mineralogy typically is mixed and the particle-size class is fine family.
The platy structure in the 2C horizon is inherited from the shale parent material and is not a result of pedogenic processes.
Cation-exchange activity class supported by lab data, ISU, Ames, Iowa.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.
ADDITIONAL DATA:
Laboratory data--Iowa State University, Ames, Iowa-various pedons