LOCATION HANLON IA+MNEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Cumulic Hapludolls
TYPICAL PEDON: Hanlon fine sandy loam, on a nearly level flood plain, adjacent to the Cedar River, in a meadow. (Colors are for moist soil unless otherwise stated.)
A1--0 to 18 centimeters (0 to 7 inches); black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak very fine subangular blocky structure parting to weak fine granular; very friable; neutral; clear smooth boundary.
A2--18 to 69 centimeters (7 to 27 inches); black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak fine and medium subangular blocky structure; very friable; neutral; clear smooth boundary.
A3--69 to 102 centimeters (27 to 40 inches); black (10YR 2/1) fine sandy loam, very dark gray (10YR 3/1) dry; weak medium subangular blocky structure; very friable; neutral; clear smooth boundary.
A4--102 to 127 centimeters (40 to 50 inches); very dark brown (10YR 2/2) fine sandy loam grading to medium sandy loam with depth, dark grayish brown (10YR 4/2) dry; weak medium and coarse subangular blocky structure; very friable; neutral; gradual smooth boundary. [Combined thickness of the A horizon is 91 to 122 centimeters (36 to 48 inches).]
Bt--127 to 175 centimeters (50 to 69 inches); very dark grayish brown (10YR 3/2) sandy loam; weak medium and coarse subangular blocky structure; friable; some clay bridging between sand grains; very dark brown (10YR 2/2) coats on faces of peds; neutral; abrupt wavy boundary. [0 to 28 centimeters (0 to 23 inches) thick]
BC--175 to 203 centimeters (69 to 80 inches); dark grayish brown (10YR 4/2) loam; weak coarse prismatic structure; friable; strongly effervescent; slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies; Mitchell County, Iowa subset; about 1 mile west of St. Ansgar; about 30 meters (100 feet) north and 706 meters (2,315 feet) west of the southeast corner of section 23, T. 99 N., R. 18 W.; USGS Osage SW quadrangle; lat. 43 degrees 22 minutes 18 seconds N. and long. 92 degrees 56 minutes 2 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon--102 to 178 centimeters (40 to 71 inches)
Depth to carbonates--more than 122 centimeters (more than 48 inches)
Clay content of the particle-size control section (weighted average)--12 to 18 percent
Sand content of the particle-size control section (weighted average)--50 to 75 percent
A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--fine sandy loam or sandy loam
Clay content--12 to 18 percent
Sand content--50 to 75 percent
Reaction--slightly acid or neutral
Some pedons have overwash sediments 15 to 46 centimeters (6 to 18 inches) thick with textures of silt loam or loam
Bt or Bw horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--1 or 2
Texture--sandy loam, fine sandy loam, or loamy fine sand
Clay content--5 to 10 percent
Sand content--60 to 90 percent
Reaction--moderately acid to neutral
BC or BCg (when present) horizon:
Hue--10YR or 2.5Y
Value--3 or 4
Chroma--1 or 2
Texture--loam, sandy loam, loamy sand, or sand
Clay content--2 to 18 percent
Sand content--45 to 90 percent
Reaction--moderately acid to slightly alkaline
COMPETING SERIES: These are the
Ankeny,
Disco,
Eyota,
Lomax,
Shellwood, and
Tomall series.
Ankeny--have a mollic epipedon 60 to 102 centimeters (24 to 40 inches) thick
Disco--have a mollic epipedon 60 to 91 centimeters (24 to 36 inches) thick
Eyota--have a sand content of 25 to 50 percent in the middle third of the series control section
Lomax--have a mollic epipedon 60 to 91 centimeters (24 to 36 inches) thick and have a sand content of less than 50 percent in the particle-size control section
Shellwood--have carbonates throughout the series control section
Tomall--have carbonates in the lower third of the series control section and have matrix chroma of 4 to 6 in the lower third of the series control section.
GEOGRAPHIC SETTING:
Parent material--alluvium
Landform--flood plains
Slopes--0 to 3 percent
Elevation--229 to 427 meters (750 to 1,400 feet) above sea level
Mean annual air temperature--7 to 11 degrees C (45 to 52 degrees F)
Mean annual precipitation--71 to 86 centimeters (28 to 34 inches)
Frost-free period--145 to 175 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Ankeny soils, and
Coland,
Spillville,
Terril, and
Turlin soils.
Ankeny--are at slightly higher elevations on foot slopes, alluvial fans, and stream terraces and have a mollic epipedon 60 to 102 centimeters (24 to 40 inches) thick
Coland--are at lower elevations on flood plains and have a clay content of 22 to 35 percent in the particle-size control section
Spillville--are on landscape positions similar to those of the Hanlon soils and have a clay content of 18 to 26 percent in the particle-size control section
Terril--are at higher elevations on base slopes and have a clay content of 18 to 27 percent in the particle-size control section
Turlin--are at slightly higher elevations and have a clay content of 18 to 27 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Draingae class--moderately well drained--a frequently saturated zone occurs within depths of 1.2 to 1.8 meters (4 to 6 feet) during April to June in normal years
Saturated hydraulic conductivity--high
Surface runoff potential--negligible or very low
Flooding--rarely or occasionally flooded for very brief periods during the months of February to November from precipitation events and snowmelt
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, small grains, and soybeans. Some areas are pastured. The native vegetation is 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 sections--Western lake section and Dissected till plains
MLRAs--Central Iowa and Minnesota Till Prairies (103), Eastern Iowa and Minnesota Till Prairies (104), and Illinois and Iowa Deep Loess and Drift (108)
LRR M--northern Iowa and Minnesota
Extent--small
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Mitchell County, Iowa, 1971
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 39 inches);
series control section--the zone from the surface to a depth of 150 centimeters (59 inches).
Diagnostic horizons and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 175 centimeters (69 inches) (A1, A2, A3, A4, and Bt horizons);
cambic horizon--the zone from 127 to 175 centimeters (50 to 69 inches) (Bt horizon);
udic moisture regime.
The Bt horizon does not have the 1.2 percent clay increase to meet the requirements of an argillic horizon.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--Keys to Soil Taxonomy, ninth edition, 2003.