LOCATION BOLAN              IA

BOLAN SERIES

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Hapludolls

TYPICAL PEDON: Bolan loam, on a convex slope of 3 percent, in a cultivated field. (Colors are for moist soil unless otherwise noted.)

Ap--0 to 23 centimeters; very dark brown (10YR 2/2) loam, very dark grayish brown (10YR 3/2) dry, faces of peds black (10YR 2/1); moderate fine granular structure; friable; neutral; clear smooth boundary.

A--23 to 36 centimeters; very dark grayish brown (10YR 3/2) loam, dark grayish brown (10YR 4/2) dry; weak fine and very fine granular structure; friable; neutral; gradual smooth boundary. (Combined thickness of the A horizon is 25 to 49 centimeters.)

BA--36 to 48 centimeters; brown (10YR 4/3) loam, faces of a few peds are dark brown (10YR 3/3); weak fine subangular blocky structure; friable; neutral; gradual smooth boundary. (0 to 23 centimeters thick)

Bw--48 to 69 centimeters; dark yellowish brown (10YR 4/4) loam; weak medium subangular blocky structure; friable; moderately acid; gradual smooth boundary. (15 to 36 centimeters thick)

BC--69 to 94 centimeters; dark yellowish brown (10YR 4/4) fine sandy loam; weak medium subangular blocky structure; very friable; moderately acid; gradual smooth boundary. (15 to 33 centimeters thick)

2C1--94 to 140 centimeters; dark yellowish brown (10YR 4/4) loamy fine sand; single grain; very friable; moderately acid; gradual smooth boundary. (25 to 50 centimeters thick)

2C2--140 to 152 centimeters; brown (10YR 5/3) loamy fine sand, single grain; very friable; slightly acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Worth County, Iowa subset; located about 1,520 feet east and 215 feet north of the southwest corner of section 7, T. 98 N., R. 19 W.; USGS Manly topographic quadrangle; lat. 43 degrees 18 minutes 49 seconds N. and long 93 degrees 08 minutes 11 seconds W.; NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 49 centimeters
Depth to carbonates--more than 120 centimeters
Clay content of the particle-size control section (weighted average)--14 to 18 percent
Sand content of the particle-size control section (weighted average)--40 to 60 percent

Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--loam, silt loam, or sandy loam
Clay content--12 to 27 percent
Sand content--25 to 75 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

Some pedons have an AB horizon, up to 12 centimeters thick, with matrix hue of 10YR, value of 3, chroma of 2, and a texture of loam

BA horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--3
Texture--loam or sandy loam
Clay content--12 to 25 percent
Sand content--40 to 70 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

Bw horizon:
Hue--10YR
Value--3 to 6
Chroma--3 to 6
Texture--loam, fine sandy loam or loamy sand
Clay content--7 to 20 percent
Sand content--40 to 85 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

BC horizon:
Hue--10YR
Value--4 or 5
Chroma--4 to 6
Texture--fine sandy loam, loamy fine sand, or loamy sand
Clay content--7 to 15 percent
Sand content--60 to 90 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

2C horizon:
Hue--10YR
Value--4 to 6
Chroma--3 to 6
Texture--loamy fine sand, sandy loam, or sand
Clay content--2 to 10 percent
Sand content--75 to 95 percent
Rock fragment content--0 percent
Reaction--moderately acid to neutral

Some pedons have narrow bands of iron and clay accumulation and thin lenses of silt loam are present below a depth of 125 centimeters

Some pedons have loamy till below a depth of 150 centimeters

COMPETING SERIES: These are the Augusta Lake, Aureola, Bertram, Dickinson, Elrick, Etter, Filley, Flagler, Gardencity, Olin, Ridgeport, Roine, Wadenill, and Zenor series.
Augusta Lake--have a sand content of less than 50 percent in the lower third of the particle-size control section
Aureola--have carbonates within a depth of 100 centimeters
Bertram--have a lithic contact with limestone bedrock within a depth of 100 centimeters
Dickinson--have a sand content that averages 60 to 80 percent in the particle-size control section
Elrick--have a sand content that averages 65 to 80 percent in the particle-size control section
Etter--have sandy residuum from sandstone within a depth of 100 centimeters and have a rock fragment content of 2 to 35 percent in the lower third of the series control section
Filley--have a clay content that averages 5 to 18 percent and have a sand content that averages 52 to 85 percent in the particle-size control section
Flagler--have a rock fragment content of 5 to 15 percent in the lower half of the series control section
Gardencity--have a sand content that averages 15 to 50 percent in the particle-size control section and have a clay content of 9 to 15 percent in the lower third of the series control section
Olin--have a clay content of 18 to 27 percent in the lower half of the series control section
Ridgeport--have carbonates within a depth of 120 centimeters
Roine--have a clay content of 25 to 33 percent in the lower third of the series control section
Wadenill--have a rock fragment content of 5 to 15 percent in the series control section
Zenor--have carbonates within a depth of 100 centimeters

GEOGRAPHIC SETTING:
Parent material--loamy eolian material or alluvial sediments
Landform--convex slopes on till plains, moraines, dissected till plains and treads and risers on stream terraces
Slope--0 to 14 percent
Elevation--155 to 520 meters above sea level
Mean annual air temperature--6 to 11 degrees C
Mean annual precipitation--585 to 965 millimeters
Frost-free period--155 to 205 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dickinson, Lawler, Saude, and Waukee soils.
Dickinson--are on landscape positions similar to those of the Bolan soils and have a sand content that averages 60 to 80 percent in the particle-size control section
Lawler--are at slightly lower landscape positions on stream terraces and have a frequently saturated zone at depths of 0.3 to 1 meter during the wettest parts of years when precipitation is within one standard deviation of the 30 year mean of annual precipitation
Saude--are on landscape positions similar to those of the Bolan soils and have a rock fragment content of 5 to 50 percent in the lower third of the series control section
Waukee--are on landscape positions similar to those of the Bolan soils and have a rock fragment content of 10 to 50 percent 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 in years 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 in the upper materials and 10.00 to 100.00 micrometers per second in the underlying materials

USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, legume hay, small grains, and soybeans. The native vegetation is big bluestem, indiangrass, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Dissected till plains and Western lake section
MLRAs--Central Iowa and Minnesota Till Prairies (103),
Eastern Iowa and Minnesota Till Prairies (104),
Iowa and Minnesota Loess Hills (107A), and
Illinois and Iowa Deep Loess and Drift, West-Central Part (108C)
LRR M; north-central, northwestern, and east-central Iowa
Extent--small

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Worth County, Iowa, 1972.

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:
mollic epipedon-the zone from the surface to a depth of 36 centimeters (Ap and A horizons);
cambic horizon--the zone from a depth of 36 to 94 centimeters (BA, Bw, and BC horizons);
udic moisture regime.

This unit was formerly mapped as Waukegan loam, and subsequently as Saude, Wadena, or Waukee soils.

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.