LOCATION LAWSON WI+IA IL MN MOEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aquic Cumulic Hapludolls
TYPICAL PEDON: Lawson silt loam, on a 1 percent slope, in an uncultivated field, at an elevation of about 265 meters above mean sea level. (Colors are for moist soil unless otherwise stated.)
A1--0 to 30 centimeters; very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure parting to moderate medium and fine granular; friable; many roots; neutral; clear wavy boundary.
A2--30 to 48 centimeters; black (10YR 2/1) and very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure parting to moderate medium and fine granular; friable; many roots; neutral; clear wavy boundary.
A3--48 to 76 centimeters; black (10YR 2/1) and very dark brown (10YR 2/2) silt loam, grayish brown (10YR 5/2) dry; moderate fine subangular blocky structure; friable; neutral; clear wavy boundary. (Combined thickness of the A horizon is 60 to 90 centimeters.)
C1--76 to 102 centimeters; very dark gray (10YR 3/1) and black (10YR 2/1) silty clay loam stratified with thin lenses of silt loam and loam; moderate medium angular and subangular blocky structure; firm; neutral; clear wavy boundary. (0 to 39 centimeters thick)
C2--102 to 152 centimeters; dark grayish brown (10YR 4/2) silt loam interlayered with thin lenses of loam and sandy loam; massive with a few thin, coarse-textured strata; friable; common fine prominent yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; neutral.
TYPE LOCATION: Major Land Resource Area (MLRA) 105-Northern Mississippi Valley Loess Hills, Iowa County, Wisconsin subset; about 4 miles south-southeast of Mineral Point; located about 1,000 feet east and 2,400 feet south of the northwest corner of section 17, T. 4 N., R. 3 E.; USGS Mineral Point topographic quadrangle; lat. 42 degrees 49 minutes 21 seconds N. and 90 degrees 10 minutes 06 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--60 to 90 centimeters
Clay content in the particle-size control section (weighted average)--18 to 30 percent
Sand content in the particle-size control section (weighted average)--5 to 20 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--10 to 35 percent
Sand content--5 to 20 percent
Rock fragment content--0 percent
Reaction--slightly acid to slightly alkaline
C horizon:
Hue--10YR or 2.5Y
Value--3 to 6
Chroma--1 to 3
Texture--silt loam or silty clay loam, or stratified with silt loam, silty clay loam, loam, and sandy loam, thin strata of coarser texture are common
Clay content--10 to 30 percent
Sand content--5 to 60 percent
Rock fragment content--0 percent
Reaction--slightly acid to slightly alkaline
Distinct or prominent redoximorphic features generally are in the horizons below the mollic epipedon
COMPETING SERIES: These are the
Ely,
Littleton and
Smithland series.
Ely--have a clay content that averages 27 to 35 percent and have a cambic horizon
Littleton--have a cambic horizon
Smithland--have a mollic epipedon more than 90 centimeters thick and have a cambic horizon
GEOGRAPHIC SETTING:
Parent material--silty alluvium
Landform--flood plains and upland drainageways
Slope--0 to 5 percent
Elevation--100 to 470 meters above sea level
Mean annual air temperature--4 to 14 degrees C
Mean annual precipitation--700 to 1,140 millimeters
Frost-free period--125 to 210 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Boaz,
Chaseburg,
Huntsville, and
Orion soils.
Boaz--are on landscape positions similar to those of the Lawson soils, have an ochric epipedon a cambic horizon
Chaseburg--are at higher landscape positions and do not have a frequently saturated zone within a depth of 1.8 meters for during the wettest periods of normal years
Huntsville--are at slightly higher landscape positions on flood plains and have a frequently saturated zone at a depth of 1.2 meters during the wettest periods of normal years
Orion--are on landscape positions similar to those of the Lawson soils, have a buried horizon and have an average clay content of 10 to 18 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a frequently saturated zone occurs within depths of 0.3 to 0.9 meter during the wettest periods of normal years and is considered apparent
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second (moderately high)
Surface runoff potential--negligible to low
Flooding--rarely to frequently flooded for very brief to long duration
USE AND VEGETATION:
Many areas are used for forage production. Cultivated areas produce good crop yields where excess water is not a problem. Native vegetation consists of scattered silver maple, white ash, American elm trees, tall prairie grasses, and forbs.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Wisconsin driftless section, Till plains, Western lake section, Eastern lake section, and Dissected till plains
MLRAs--Wisconsin and Minnesota Sandy Outwash (91),
Southern Wisconsin and Northern Illinois Drift Plain (95B),
Eastern Iowa and Minnesota Till Prairie (104),
Northern Mississippi Valley Loess Hills (105),
Illinois and Iowa Deep Loess and Drift (108),
Iowa and Missouri Heavy Till Plain (109),
Northern Illinois and Indiana Heavy Till Plain (110),
Southern Illinois and Indiana Thin Loess and Till Plain (114), and
Central Mississippi Valley Wooded Slopes (115)
LRR K and M; west central and southwestern Wisconsin, southeastern Minnesota, northwestern Illinois, and eastern Iowa
Extent--large
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota.
SERIES ESTABLISHED: Lafayette County, Wisconsin, 1964.
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 of the soil to a depth of 76 centimeters (A1, A2, and A3 horizons);
cumulic property--mollic epipedon more than 60 centimeters thick and, greater than 0.3 percent organic carbon at a depth of 125 centimeters and/or an irregular decrease of organic carbon with increasing depth from 25 to 125 centimeters;
udic moisture regime;
mesic temperature regime.
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.
ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska - user pedon ID 76IA103005 (http://ssldata.nrcs.usda.gov/).