LOCATION OLIN IA+MNEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Olin fine sandy loam, on a slope of 3 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 centimeters (0 to 8 inches); very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure; very friable; common very fine and fine roots; neutral; abrupt smooth boundary.
A--20 to 48 centimeters (8 to 19 inches); very dark brown (10YR 2/2) fine sandy loam, dark grayish brown (10YR 4/2) dry; weak fine and medium subangular blocky structure; very friable; common very fine roots; slightly acid; clear smooth boundary. [Combined thickness of the A horizon is 40 to 50 centimeters (16 to 20 inches).]
Bw1--48 to 64 centimeters (19 to 25 inches); brown (10YR 4/3) sandy loam; weak medium subangular blocky structure; very friable; few very fine roots; few faint discontinuous dark brown (10YR 3/3) organic coats on faces of peds; moderately acid; clear smooth boundary.
Bw2--64 to 79 centimeters (25 to 31 inches); dark yellowish brown (10YR 4/4) sandy loam; weak medium subangular blocky structure; very friable; few very fine roots; discontinuous stone line consisting of rounded gravel and cobbles 2 to 15 centimeters (1 to 6 inches) in diameter (5 to 10 percent of this horizon); strongly acid; clear smooth boundary. [Combined thickness of the Bw horizon is 20 to 40 centimeters (8 to 16 inches).]
2Bw3--79 to 135 centimeters (31 to 53 inches); about 60 percent dark yellowish brown (10YR 4/6) and about 40 percent brown (10YR 5/3) loam; weak medium prismatic structure; firm; common fine dark reddish brown (5YR 3/2) masses of iron-manganese; moderately acid; gradual smooth boundary. [40 to 60 centimeters (16 to 24 inches) thick]
2BC1--135 to 170 centimeters (53 to 67 inches); strong brown (7.5YR 5/6) loam; extremely coarse prismatic structure dissected by few oblique fractures; very firm; common fine very dark brown (7.5YR 2/2) masses of iron-manganese; common medium prominent light brownish gray (2.5Y 6/2) redoximorphic depletions; about 2 percent rock fragments (2 to 75 millimeters in diameter); slightly acid; gradual smooth boundary.
2BC2--170 to 203 centimeters (67 to 80 inches); strong brown (7.5YR 5/6) loam; extremely coarse prismatic structure dissected by few oblique fractures; very firm; common fine very dark brown (7.5YR 2/2) masses of iron-manganese; about 2 percent rock fragments (2 to 75 millimeters in diameter); neutral.
TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies; Black Hawk County, Iowa subset; about 2 miles south and 3 miles east of Dunkerton; about 70 meters (230 feet) north and 82 meters (270 feet) west of the southeast corner of section 2, T. 89 N., R. 11 W.; USGS Littleton quadrangle; lat. 42 degrees 32 minutes 29.3 seconds N. and long. 92 degrees 6 minutes 11.6 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--40 to 50 centimeters (16 to 20 inches)
Depth to the glacial till--60 to 91 centimeters (24 to 36 inches)
Depth to carbonates--125 to more than 203 centimeters (50 to more than 80 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)--60 to 85 percent
Special feature--some pedons have a stone line or thin layer, 2 to 13 centimeters (1 to 5 inches) thick of gravelly and sandy materials at the base of the silty or loamy sediments
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--2
Texture--fine sandy loam or sandy loam
Clay content--12 to 18 percent
Sand content--55 to 75 percent
Rock fragment content--1 to 10 percent
Reaction--moderately acid to neutral
BA horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--3
Texture--fine sandy loam or sandy loam
Clay content--12 to 18 percent
Sand content--55 to 75 percent
Rock fragment content--1 to 10 percent
Reaction--strongly acid to neutral
Bw horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--sandy loam with or without 15 to 20 centimeters (6 to 8 inches) thick layers of loamy sand
Clay content--12 to 18 percent
Sand content--60 to 85 percent
Rock fragment content--1 to 10 percent
Reaction--strongly acid to neutral
2Bw horizon:
Hue--10YR
Value--4 or 5
Chroma--3 to 6
Texture--loam, clay loam, or sandy clay loam
Clay content--20 to 28 percent
Sand content--30 to 70 percent
Rock fragment content--2 to 12 percent
Reaction--strongly acid to neutral
2BC horizon:
Hue--7.5YR or 10YR
Value--4 to 6
Chroma--4 to 8
Texture--loam
Clay content--18 to 27 percent, mean of 22 percent
Sand content--35 to 50 percent, mean of 44 percent
Rock fragment content--2 to 12 percent
Reaction--slightly acid to moderately alkaline
Moist bulk density--1.75 to 1.9 g/cc
COMPETING SERIES: These are the
Aureola,
Becker,
Bertram,
Bolan,
Dickinson,
Elrick,
Etter,
Filley,
Flagler,
Gardencity,
Ridgeport,
Roine,
Wadenill, and
Zenor series.
Aureola--have carbonates within depths of 50 to of 102 centimeters (20 to 40 inches)
Becker--have a mollic epipedon 60 to 102 centimeters (24 to 40 inches) thick
Bertram--have a lithic contact within depths of 50 to 102 centimeters (20 to 40 inches)
Bolan--have a clay content of 12 to 32 percent in the upper third of the series control section and have a sand content of greater than 50 percent in the lower third of the series control section
Dickinson--have a sand content of 80 to 95 percent in the lower third of the series control section
Elrick--have a sand content of more than 50 percent medium sand and coarser sand in the lower third of series control section
Etter--have a clay content of less than 10 percent in the lower third of the series control section
Filley--have a sand content of greater than 50 percent in the lower third of the series control section
Flagler--have a sand content of greater than 50 percent in the lower third of the series control section
Gardencity--have a sand content of 15 to 50 percent in the particle-size control section
Ridgeport--have carbonates within a depth of 50 to 102 centimeters (20 to 40 inches)
Roine--have mollic epipedons 25 to 40 centimeters (10 to 16 inches) thick and have a frequently saturated zone within depths of 1.2 to 1.8 meters (4 to 6 feet) in normal years
Wadenill--have carbonates within depths of 46 to 102 centimeters (18 to 40 inches)
Zenor--have carbonates within depths of 50 to 102 centimeters (20 to 40 inches)
GEOGRAPHIC SETTING:
Parent material--formed in 60 to 91 centimeters (24 to 36 inches) of loamy sediments and in the underlying glacial till
Landform--interfluves and side slopes on dissected till plains
Slopes--2 to 14 percent
Elevation--213 to 396 meters (700 to 1,300 feet) above sea level
Mean annual air temperature--7 to 11 degrees C (45 to 51 degrees F)
Mean annual precipitation--81 to 86 centimeters (32 to 34 inches)
Frost-free period--150 to 175 days
GEOGRAPHICALLY ASSOCIATED SOILS: Members of the typical catena include
Dickinson,
Kenyon,
Schley, and
Sparta soils.
Dickinson--are on landscape positions similar to those of the Olin soils and have a sand content of 80 to 95 percent in the lower third of the series control section
Kenyon--are on landscape positions similar to those of the Olin soils and have a clay content of 20 to 28 percent in the particle-size control section
Schley--are at slightly lower elevations and have a frequently saturated zone within a depth of 0.3 to 1 meter (1 to 3.25 feet) in normal years
Sparta--are on landscape positions similar to those of the Olin soils and have a clay content of less than 10 percent in the particle-size 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 (6 feet) in normal years
Saturated hydraulic conductivity--10.00 to 100.00 micrometers per second in the upper sediments and 0.10 to 1.00 micrometers per second in the underlying glacial till
Surface runoff potential--very low or low
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, small grains, and legume hay. 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 section--Dissected till plains
MLRAs--Eastern Iowa and Minnesota Till Prairies (104) and Illinois and Iowa Deep Loess and Drift (108)
Local physiographic area--Iowa Erosion Surface
LRR M--northeastern Iowa and southeastern Minnesota
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Linn County, Iowa, 1970
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 39 inches) (A, Bw1, Bw2, and 2Bw3 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (0 to 59 inches) (Ap, A, Bw1, Bw2, 2Bw3, and 2BC1 horizons).
Diagnostic horizons and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 48 centimeters (0 to 19 inches) (Ap and A horizons);
cambic horizon--the zone from a depth of 48 to 203 centimeters (19 to 80 inches) (Bw1, Bw2, 2Bw3, 2BC1, and 2BC2 horizons);
udic moisture regime.
The difference in saturated hydraulic conductivity tends to move water laterally in wet seasons, and seepy spots are in some areas for short periods.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
The type location was changed from Linn County, Iowa to Black Hawk County, Iowa as the former pedon classified as Pachic Hapludolls.
The majority of pedons observed in the field have mollic epipedons less than 50 centimeters thick.
The MLRA 104 Steering Committee approved property edits to this series in February 2004.
Taxonomy version--Keys to Soil Taxonomy, ninth edition, 2003.