LOCATION DINSMORE IA+MNEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Dinsmore silty clay loam, on a 2 percent slope, in a cultivated field. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 20 centimeters (0 to 8 inches); very dark brown (10YR 2/2) silty clay loam, very dark grayish brown (10YR 3/2) dry; weak fine granular structure; friable; common fine roots; common very fine tubular pores; slightly acid; clear smooth boundary.
A1--20 to 30 centimeters (8 to 12 inches); very dark brown (10YR 2/2) silty clay loam, very dark grayish brown (10YR 3/2) dry; weak very fine subangular blocky structure; friable; common fine roots; common very fine tubular pores; moderately acid; clear smooth boundary.
A2--30 to 41 centimeters (12 to 16 inches); very dark grayish brown (10YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure; friable; common very fine roots; common very fine tubular pores; moderately acid; gradual smooth boundary. [Combined thickness of the A horizon is 25 to 50 centimeters (10 to 20 inches).]
Bt1--41 to 56 centimeters (16 to 22 inches); brown (10YR 4/3) silty clay loam; moderate fine and medium subangular blocky structure; friable; few very fine roots; common very fine tubular pores; few distinct dark grayish brown (10YR 4/2) clay films on vertical faces of peds; moderately acid; gradual smooth boundary.
Bt2--56 to 76 centimeters (22 to 30 inches); brown (10YR 4/3) silty clay loam; moderate medium subangular blocky structure; friable; few very fine roots; common very fine tubular pores; few distinct dark grayish brown (10YR 4/2) clay films on faces vertical of peds; strongly acid; gradual smooth boundary.
Bt3--76 to 91 centimeters (30 to 36 inches); brown (10YR 5/3) silty clay loam; weak medium subangular blocky structure; friable; few very fine roots; common very fine tubular pores; few distinct grayish brown (10YR 5/2) clay films on vertical faces of peds; moderately acid; gradual smooth boundary.
Bt4--91 to 122 centimeters (36 to 48 inches); yellowish brown (10YR 5/4) silty clay loam; weak medium subangular blocky structure; friable; common very fine tubular pores; few distinct grayish brown (10YR 5/2) clay films on vertical faces of peds; 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); slightly acid; gradual smooth boundary. [Combined thickness of the Bt horizon is 76 to 102 centimeters (30 to 40 inches).]
2BC--122 to 203 centimeters (48 to 80 inches); yellowish brown (10YR 5/4) loam; extremely coarse prismatic structure dissected by few oblique fractures; very firm; few very fine tubular pores; common medium distinct strong brown (7.5YR 5/6) redoximorphic concentrations; common fine and medium distinct grayish brown (10YR 5/2) redoximorphic depletions; about 4 percent rock fragments (2 to 75 millimeters in diameter); slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies; Black Hawk County, Iowa subset; about 2.5 miles south west of Voorhies; about 243 meters (800 feet) east and 91 meters (300 feet) north of the southwest corner of section 30, T. 87 N., R. 14 W.; USGS Reinbeck quadrangle; lat. 42 degrees 18 minutes 44.3 seconds N. and long. 92 degrees 31 minutes 50.7 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness--25 to 50 centimeters (10 to 20 inches)
Depth to glacial till--102 to 152 centimeters (40 to 60 inches)
Depth to carbonates--102 to more than 203 centimeters (40 to more than 80 inches)
Content of clay in the particle-size control section (weighted average)--22 to 35 percent
Content of sand in the particle-size control section (weighted average)--5 to 15 percent fine sand and sand coarser than fine sand
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 and A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 to 3
Texture--silty clay loam or silt loam
Clay content--17 to 32 percent
Sand content--less than 15 percent
Reaction--moderately acid to neutral
Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--3 to 6
Texture--silty clay loam or slit loam
Clay content--22 to 35 percent
Sand content--less than 15 percent
Rock fragment content--1 to 10 percent-a stone line is commonly at the lower boundary of this horizon
Reaction--strongly acid to neutral
2BC, 2Bt (when present) or 2C horizon:
Hue--10YR or 7.5YR
Value--4 or 5
Chroma--3 to 8
Texture--loam, clay loam, or sandy clay loam
Clay content--12 to 27 percent, mean of 22 percent
Sand content--30 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 gm/cc
COMPETING SERIES: These are the
Annieville,
Biggsville,
Exira,
Galva,
Keg,
Marshall,
Monona,
Northboro,
Ponca,
Port Byron,
Raddle,
Salix, and
Truman series.
Annieville--have a moist bulk density range of 1.6 to 1.8 gm/cc in the lower third of the series control section
Biggsville--have a clay content of 18 to 27 percent in the particle-size control section and have a moist bulk density of less than 1.6 gm/cc in the lower third of the series control section
Exira--have redoximorphic features within a depth of 76 centimeters (30 inches)
Galva--have carbonates within depths of 81 to 183 centimeters (32 to 72 inches) and have a sand content of 1 to 10 percent in the lower third of the series control section
Keg--have carbonates within depths of 61 to 142 centimeters (24 to 56 inches) and have a clay content of 18 to 26 percent in the particle-size control section
Marshall--have a clay content of 27 to 35 percent in the particle-size control section and have a sand content of less than 10 percent in the lower third of the series control section
Monona--have a clay content of 20 to 27 percent in the particle-size control section and have a sand content of less than 10 percent in the lower third of the series control section
Northboro--have matrix hues of 5YR or 7.5YR in the middle third of the series control section
Ponca--have carbonates within depths of 36 to 61 centimeters (14 to 24 inches)
Port Byron--have a clay content of 18 to 27 percent in the particle-size control section and have a sand content of less than 10 percent in the lower third of the series control section
Raddle--have a clay content of 18 to 24 percent in the particle-size control section and have a sand content of less than 30 percent in the lower third of the series control section
Salix--have carbonates within depths of 51 to 91 centimeters (20 to 36 inches)
Truman--have carbonates within depths of 46 to 142 centimeters (18 to 56 inches), have a clay content of 18 to 32 percent in the particle-size control section, and have a calcium carbonate equivalent range of 5 to 15 percent in the lower third of the series control section
GEOGRAPHIC SETTING:
Parent material--102 to 152 centimeters (40 to 60 inches) of loess and the underlying glacial till
Landform--interfluves, ridges and side slopes on dissected till plains
Slopes--2 to 15 percent
Elevation--198 to 396 meters (650 to 1300 feet) above sea level
Mean annual air temperature--7 to 12 degrees C (45 to 53 degrees F)
Mean annual precipitation--76 to 89 centimeters (30 to 35 inches)
Frost-free period--130 to 186 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Klingmore,
Maxmore, and
Tama soils.
Klingmore--are at lower elevations on head slopes, side slopes, and base slopes and are frequently saturated within depths of 0.3 to 0.9 meter (1.0 to 3.0 feet) in normal years
Maxmore--are at lower elevations on head slopes and toe slopes and are frequently saturated within depths of 0 to 0.3 meter (0 to 1.0 foot) in normal years
Tama--are on similar landscape positions as the Dinsmore soils and have a sand content of less than 10 percent in the lower third of the series control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs within depths of 1 to 1.8 meters (3.5 to 6.0 feet) during April to June in normal years and both perched and apparent saturation can occur on this soil based on the season and intensity of rainfall during a given period of time
Saturated hydraulic conductivity--moderately high in the loess and low or moderately low in the glacial till
Surface runoff potential--low or medium
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn and soybeans. 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(s)--Dissected till plains
MLRA--Eastern Iowa and Minnesota Till Prairies (104)
LRR M; northeastern Iowa and southeastern Minnesota
Extent--small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Black Hawk County, Iowa, 2001.
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 40 inches) (A1, A2, Bt1, Bt2, Bt3 and Bt4 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (0 to 60 inches) (Ap, A1, A2, Bt1, Bt2, Bt3, Bt4, and 2BC horizons).
Diagnostic horizons and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 41 centimeters (0 to 16 inches) (Ap, A1, and A2 horizons);
cambic horizon--the zone from a depth of 41 to 122 centimeters (16 to 48 inches) (Bt1, Bt2, Bt3, and Bt4 horizons);
udic moisture regime.
The Bt horizon does not have the 1.2 percent clay increase to meet the requirements of an argillic horizon.
Some pedons have vertical seams or wedges of sand or loamy sand about 5 to 15 centimeters (2 to 6 inches) wide and about 0.9 to 1.2 meters (3 to 4 feet) deep extending downward from the stone line into the glacial till.
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.
The MLRA 104 Steering Committee approved property edits to this series in February 2004.