LOCATION SHARPSBURG         IA+KS MO

SHARPSBURG SERIES

TAXONOMIC CLASS: Fine, smectitic, mesic Typic Argiudolls

TYPICAL PEDON: Sharpsburg silty clay loam, on a convex slope of 8 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; black (10YR 2/1) silty clay loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure; friable; few fine roots; slightly acid; abrupt smooth boundary.

A1--20 to 28 centimeters; very dark brown (10YR 2/2) silty clay loam, dark grayish brown (10YR 4/2) dry; moderate very fine subangular blocky structure; friable; slightly acid; clear smooth boundary.

A2--28 to 43 centimeters; very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (10YR 5/2) dry; some brown (10YR 4/3) peds; moderate very fine subangular blocky structure; friable; moderately acid; gradual smooth boundary. (Combined thickness of the A horizon is 25 to 49 centimeters.)

Bt1--43 to 61 centimeters; brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure parting to weak fine subangular blocky; firm; very few fine roots; common distinct very dark grayish brown (10YR 3/2) clay films on faces of peds; very dark gray (10YR 3/1) organic stains on faces of peds; moderately acid; gradual smooth boundary.

Bt2--61 to 79 centimeters; brown (10YR 4/3) and yellowish brown (10YR 5/4) silty clay loam; weak medium prismatic structure parting to moderate fine subangular blocky; firm; very few fine and medium roots; many distinct dark grayish brown (10YR 4/2) clay films on faces of peds; few fine iron and manganese oxide concretions; few fine distinct light brownish gray (2.5Y 6/2) redoximorphic depletions; moderately acid; gradual smooth boundary.

Bt3--79 to 97 centimeters; brown (10YR 5/3) silty clay loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; many prominent grayish brown (10YR 5/2) clay films on faces of peds; few fine iron and manganese oxide concretions; common medium faint light brownish gray (2.5Y 6/2) redoximorphic depletions; common medium prominent strong brown (7.5YR 5/6) redoximorphic concentrations; moderately acid; gradual smooth boundary. (Combined thickness of the Bt horizon is 50 to 100 centimeters.)

BC--97 to 117 centimeters; yellowish brown (10YR 5/4) silty clay loam; weak medium prismatic structure; firm; common distinct grayish brown (10YR 5/2) clay films on faces of peds; few fine iron and manganese oxide concretions; many fine and medium distinct grayish brown (2.5Y 5/2) redoximorphic depletions; common medium prominent strong brown (7.5YR 5/8) redoximorphic concentrations; moderately acid; gradual smooth boundary. (10 to 25 centimeters thick)

C--117 to 152 centimeters; mottled grayish brown (2.5Y 5/2), yellowish brown (10YR 5/4), and brown (7.5YR 4/4) silty clay loam; massive; firm; very few fine roots; common fine iron and manganese oxide concretions; slightly acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 108D-Illinois and Iowa Deep Loess and Drift, Western Part, Taylor County Iowa subset; about 8 miles north and 5 miles east of Bedford; located about 1,870 feet east and 540 feet south of the northwest corner of section 10, T. 69 N., R. 33 W.; USGS Gravity topographic quadrangle; lat. 40 degrees 47 minutes 52 seconds N. and long. 94 degrees 38 minutes 10 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 49 centimeters
Depth to carbonates--more than 150 centimeters
Clay content in the particle-size control section (weighted average)--36 to 42 percent
Sand content in the particle-size control section (weighted average)--less than 5 percent

Ap and A horizons:
Hue--10YR
Value--2 or 3
Chroma--1 to 3
Texture--silt loam or silty clay loam
Clay content--25 to 34 percent clay
Sand content--less than 5 percent
Reaction--strongly acid to slightly acid

Bt horizon (upper part):
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silty clay loam or silty clay
Clay content--36 to 42 percent
Sand content--less than 5 percent
Reaction--strongly acid to slightly acid

Matrix value and chroma of 5/2 and 6/2 within depths of less than 80 centimeters are outside the range of the series

Bt horizon (lower part) or Btg (if present):
Hue--7.5YR to 5Y
Value--4 to 6
Chroma--2 to 6
Texture--silty clay loam
Clay content--30 to 38 percent clay
Sand content--less than 5 percent
Reaction--moderately acid or slightly acid

BC, BCg (if present), C, or Cg (if present) horizon:
Hue--7.5YR to 5Y
Value--4 to 6
Chroma--2 to 6
Texture--silty clay loam or silt loam
Clay content--25 to 34 percent clay
Sand content--less than 5 percent
Reaction--slightly acid or neutral

COMPETING SERIES: These are the Aksarben, Gymer, Mulholland, and Polo series.
Aksarben--do not have a frequently saturated zone within a depth of 1.8 meters during the wettest periods when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Gymer--have argillic horizons with matrix hue of 5YR or 7.5YR
Mulholland--have a sand content that averages 15 to 40 percent in the particle-size control section
Polo--have argillic horizons with matrix hues of 5YR or 7.5YR

GEOGRAPHIC SETTING:
Parent material--loess
Landscape--dissected till plains and stream terraces
Landform--interfluves and side slopes on dissected till plains and on treads and risers on stream terraces
Slope shape--convex
Hillslope position--summit and back slope
Geomorphic component--interfluve, side slope, and tread and riser
Slope--0 to 18 percent
Elevation--200 to 400 meters above sea level
Mean annual air temperature--8 to 17 degrees C
Mean annual precipitation--660 to 1,145 millimeters
Frost-free period--155 to 255 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adair, Lamoni, Macksburg and Nira soils.
Adair--are at slightly lower landscape positions and have a sand content that averages 15 to 35 percent in the particle-size control section
Lamoni--are at slightly lower landscape positions and have a sand content that averages more than 15 percent in the particle-size control section
Macksburg--are at higher landscape positions on interfluves and have a frequently saturated zone within depths of 0.3 to 1.0 meter during the wettest periods when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Nira--are at higher landscape positions on side slopes and have a clay content that averages 30 to 35 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs at depths between 1.2 and 1.8 meters during the wettest periods when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and hay. The native vegetation is big bluestem, western wheatgrass, sedges, blue grama and other species of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Provinces--Central Lowlands
Physiographic sections--Dissected till plains, Till plains and Osage plain
Land Resource Regions--Central Great Plains Winter Wheat and Range region (H) and Central Feed Grains and Livestock Region (M)
Major Land Resource Areas--Bluestem Hills (76),
Nebraska and Kansas Loess-Drift Hills (106),
Iowa and Missouri Deep Loess Hills (107B),
Illinois and Iowa Deep Loess and Drift, Western Part (108D),
Iowa and Missouri Heavy Till Plain (109), and
Cherokee Prairies (MLRA 112)
Extent--large

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Lancaster County, Nebraska, 1944.

REMARKS:
Particle-size control section--the zone from a depth of 43 to 93 centimeters;
series control section--the zone from the surface to a depth of 150 centimeters.

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface of the soil to a depth of 43 centimeters (Ap, A1, and A2 horizons);
argillic horizon--the zone from a depth of 43 to 97 centimeters (Bt1, Bt2, and Bt3 horizons);
udic soil moisture regime.

Redoximorphic features above a depth of 100 centimeters are believed to be related to precipitation events in abnormal years.

Thickness of the A horizon, depth to clay maximum, maximum percent clay, thickness of the Bt horizon, and depth to redoximorphic features decrease as gradient increases on convex slopes.

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