LOCATION CHURCHTOWN IA+MN WIEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Hapludalfs
TYPICAL PEDON: Churchtown loam, on a southeast-facing, plane slope 16 percent, in a hay field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 centimeters; very dark grayish brown (10YR 3/2) loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; friable; common fine roots; neutral; abrupt smooth boundary. (15 to 23 centimeters thick)
Bt1--23 to 43 centimeters; brown (10YR 4/3) silt loam; moderate fine subangular blocky structure; friable; few fine roots; common distinct dark brown (10YR 3/3) clay films on faces of peds; few distinct light gray (10YR 7/2) dry silt coats on faces of peds; neutral; gradual smooth boundary.
Bt2--43 to 61 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; moderate fine and medium subangular blocky structure; friable; few very fine roots; many distinct dark brown (10YR 3/3) clay films on faces of peds; few distinct light gray (10YR 7/2) dry silt coats on faces of peds; neutral; clear smooth boundary.
Bt3--61 to 76 centimeters; dark yellowish brown (10YR 4/4) silty clay loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; few very fine roots; common distinct brown (10YR 4/3) clay films on faces of peds; common distinct light gray (10YR 7/2) dry silt coats on faces of peds; few distinct dark brown (10YR 3/3) organic coats on faces of peds; neutral; gradual smooth boundary.
2Bt4--76 to 112 centimeters; dark yellowish brown (10YR 4/4) silt loam; weak medium prismatic structure; friable; few very fine roots; common distinct brown (10YR 4/3) clay films on faces of peds; few distinct light gray (10YR 7/2) dry silt coats on faces of peds; few distinct dark brown (10YR 3/3) organic coats on faces of peds; neutral; gradual smooth boundary.
2Bt5--112 to 152 centimeters; yellowish brown (10YR 5/4) silt loam; weak medium prismatic structure; friable; common distinct brown (10YR 4/3) clay films on faces of peds; very few distinct light gray (10YR 7/2) silt coats on faces of peds; few distinct dark brown (10YR 3/3) organic coats on faces of peds; neutral. (Combined thickness of the Bt horizon is 107 to 152 centimeters.)
TYPE LOCATION: Major Land Resource Area (MLRA) 105-Northern Mississippi Valley Loess Hills, Allamakee County, Iowa subset; about 4 miles north of Waukon; located about 2,100 feet east and 1,600 feet south of the northwest corner of section 2, T. 98 N., R. 6 W.; USGS Hanover topographic quadrangle; lat. 43 degrees 20 minutes 15 seconds N. and long. 91 degrees 31 minutes 9 seconds W; NAD83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--more than 150 centimeters
Clay content in the particle-size control section (weighted average)--22 to 27 percent
Sand content in the particle-size control section (weighted average)--10 to 15 percent, dominantly medium and fine sand
Rock fragment content--0 to 10 percent, channers and flagstones
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 to 3
Texture--loam or silt loam
Clay content--18 to 27 percent
Sand content--15 to 50 percent
Reaction--strongly acid to neutral
E horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--2
Texture--loam or silt loam
Clay content--18 to 25 percent
Sand content--15 to 50 percent
Reaction--strongly acid to neutral
Bt or 2Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--3 to 6
Texture--silt loam, silty clay loam, or loam
Clay content--20 to 35 percent
Sand content--5 to 30 percent
Reaction--strongly acid to neutral
2C horizon (when present):
Hue--10YR
Value--4 to 6
Chroma--4 to 6
Texture--silt loam or silty clay loam
Clay content--20 to 30 percent
Sand content--less than 10 percent
Reaction--moderately acid to moderately alkaline
COMPETING SERIES: These are the
Batavia,
Bowes,
Deroin,
Downs,
Ella,
Festina,
Frankville,
Gladek,
Greenbush,
Harvard,
Hersey,
Knox,
Luana,
Mannon,
Massbach,
Mellott,
Mt. Carroll,
Myrtle,
Nasset,
Newhouse,
Oak Center,
Watkins,
Waubeek, and
Yutan series.
Batavia--have a clay content that averages 27 to 35 percent in the particle-size control section
Bowes--have a rock fragment content that averages more than 20 percent in the lower third of the series control section
Deroin--have a clay content that averages 27 to 35 percent in the particle-size control section
Downs--have a sand content that averages less than 10 percent in the particle-size control section
Ella--have a frequently saturated zone that occurs at a depth of 1 meter during the wettest period of normal years
Festina--have a sand content of less than 15 percent in the upper third of the series control section
Frankville--have a lithic contact of dolomitic limestone within a depth of 100 centimeters
Gladek--have carbonates within a depth of 150 centimeters
Greenbush--have a clay content that averages 27 to 35 percent in the particle-size control section
Harvard--have a clay content that averages 27 to 35 percent in the particle-size control section
Hersey--have a sand content that averages more than 15 percent in the lower third of the series control section
Knox--have a sand content of less than 5 percent throughout the series control section
Luana--have residuum weathered from arenaceous limestone within a depth of 100 centimeters
Mannon--have a sand content that averages less than 10 percent in the particle-size control section
Massbach--have a paralithic contact with clay shale within a depth of 150 centimeters
Mellott--have carbonates in the lower third of the series control section
Mt. Carroll--have a sand content of less than 15 percent sand throughout the series control section
Myrtle--have matrix hue of 5YR or redder in some part of the series control section
Nasset--have a lithic contact of limestone within a depth of 150 centimeters
Newhouse--have a sand content of 30 to 90 percent in the lower third of the series control section
Oak Center--have a sand content of more than 80 percent in the lower third of the series control section
Watkins--have a clay content that averages 30 to 35 percent in the particle-size control section
Waubeek--have a sand content that averages more than 30 percent in the lower third of the series control section
Yutan--have a clay content that averages 27 to 35 percent in the particle-size control section
GEOGRAPHIC SETTING:
Parent material--60 to 120 centimeters of loamy sediments derived from loess and sandy bedrock residuum and in the underlying loess
Landform--plane to convex upland side slopes and foot slopes
Slope--6 to 30 percent
Elevation--200 to 400 meters above sea level
Mean annual air temperature--6 to 10 degrees C
Mean annual precipitation--760 to 965 millimeters
Frost-free period--145 to 205 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Boone,
Fayette,
Paintcreek, and
Village soils.
Boone--are at higher landscape positions and have a paralithic contact with sandstone within a depth of 100 centimeters
Fayette--are on landscape positions similar to those of the Churchtown soils and have a sand content of less than 5 percent throughout the series control section
Paintcreek--are at slightly lower landscape positions and have a clay content that averages 40 to 60 percent in the particle-size control section
Village--are at slightly lower landscape positions and have a clay content that averages 35 to 70 percent clay in the lower half of the series control section
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 normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second
Surface runoff potential--medium or high
USE AND VEGETATION:
The more gently sloping areas are commonly cultivated. The principal crops include corn, small grain, and legume hay. The more steeply sloping areas are pastured or wooded. The native vegetation is mixed deciduous trees (oak and hickory) and big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic division--Interior plains
Physiographic Province--Central Lowland
Physiographic section--Wisconsin driftless section
MLRA-Northern Mississippi Valley Loess Hills (105)
LRR M; northeastern Iowa, southwestern Wisconsin, and southeastern Minnesota
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Allamakee County, Iowa, 1989. The name is from a small unincorporated town in the county.
REMARKS:
Particle-size control section--the zone from a depth of 23 to 73 centimeters;
series control section--the zone from the surface to a depth of 152 centimeters.
Diagnostic horizons and features recognized in this pedon include:
ochric epipedon--the zone from the surface of the soil to a depth of 23 centimeters (Ap horizon);
argillic horizon--the zone from 23 to 152 centimeters (Bt1, Bt2, Bt3, 2Bt4, and 2Bt5 horizons);
udic moisture regime.
Some pedons may border on the fine-loamy particle-size class.
These soils are commonly below steep and very steep soils derived from colluvium or weathered sandstone.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.