LOCATION WACOUSTA                IA+MN WI

Established Series
Rev. TEF-RJW-TWN
03/2014

WACOUSTA SERIES

The Wacousta series consists of very deep, very poorly drained soils formed in silty lacustrine sediments. These soils are in broad depressions and swales on till plains, moraines, and stream terraces. Slope ranges from 0 to 2 percent. Mean annual air temperature is about 8 degrees C. Mean annual precipitation is about 775 millimeters

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Endoaquolls

TYPICAL PEDON: Wacousta silty clay loam, in a depression with a slope of less than 1 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters; black (N 2/0) silty clay loam, very dark gray (10YR 3/1) dry; weak fine and medium granular structure; friable; many fine and medium roots; neutral; abrupt smooth boundary.

A--20 to 43 centimeters; black (N 2/0) silty clay loam, dark gray (10YR 4/1) dry; weak medium subangular blocky structure; friable; many fine and medium roots; neutral; abrupt smooth boundary. (Combined thickness of the A horizon is 20 to 49 centimeters.)

Bg--43 to 64 centimeters; dark gray (5Y 4/1) silty clay loam; weak medium subangular blocky structure; friable; many fine and medium roots; common fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; neutral; clear smooth boundary. (5 to 15 centimeters thick)

Cg1--64 to 104 centimeters; gray (5Y 5/1) silt loam; massive; friable; common fine and medium roots; few fine rounded light gray (10YR 7/2) carbonate concretions; common medium prominent yellowish red (5YR 5/6) redoximorphic concentrations; slightly effervescent; slightly alkaline; clear smooth boundary.

Cg2--104 to 150 centimeters; gray (5Y 5/1) silt loam; massive; friable; few fine and medium roots; few fine black (10YR 2/1) iron-manganese concretions; few fine rounded light gray (10YR 7/2) carbonate concretions; common coarse prominent strong brown (7.5YR 5/6) redoximorphic concentrations; slightly effervescent; slightly alkaline; clear smooth boundary.

Cg3--150 to 200 centimeters; light olive gray (5Y 6/2) silt loam; massive; friable; thin strata of loam and sandy loam textured material at 152 to 170 centimeters; few fine and medium rounded light gray (10YR 7/2) carbonate concretions; common coarse prominent yellowish red (5YR 5/8) redoximorphic concentrations; strongly effervescent; moderately alkaline.

TYPE LOCATION: Major Land Resource Area (MLRA) 103-Central Iowa and Minnesota Till Prairies, Humboldt County, Iowa subset; located about 1,500 feet north and 150 feet east of the southwest corner of section 6, T. 92 N., R. 29 W.; USGS Bode topographic quadrangle; lat. 42 degrees 48 minutes 30 seconds N. and long. 94 degrees 19 minutes 28 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--20 to 49 centimeters
Depth to carbonates--30 to 50 centimeters
Clay content of the particle-size control section (weighted average)--24 to 35 percent
Sand content of the particle-size control section (weighted average)--5 to 15 percent

Ap or A horizon:
Hue--10YR, 2.5Y, or is neutral
Value--2
Chroma--0 or 1
Texture--silty clay loam, silt loam, or mucky silt loam
Clay content--15 to 40 percent
Sand content--5 to 20 percent
Reaction--slightly acid to slightly alkaline

Maximum clay content is typically in the lower part of the A horizon or in the Bg horizon

Bg horizon:
Hue--5Y
Value--4 to 6
Chroma--1 or 2
Texture--silty clay loam, silty clay, clay loam, or silt loam
Clay content--15 to 45 percent
Sand content--5 to 45 percent
Reaction--neutral or slightly alkaline

Cg horizon:
Hue--5Y
Value--5 or 6
Chroma--1 or 2
Texture--silt loam or silty clay loam
Clay content--18 to 30 percent
Sand content--5 to 15 percent
Rock fragment content--0 percent
Reaction--slightly alkaline or moderately alkaline
Moist bulk density--1.30 g/cc to 1.40 g/cc

Some pedons have a 2Cg horizon below a depth of 150 centimeters with stratified textures of loam, silt loam, very fine sandy loam or clay loam

COMPETING SERIES: These are the Chalmers, Chetomba, Dolbee, Drummer, Dunham, Elpaso, Elvira, Garwin, Gillett Grove, Hartsburg, Madelia, Marcus, Mascoutah, Maxcreek, Maxfield, Maxmore, Ossian, Patton, Pella, Rushmore, and Sable series.
Chalmers--have clay content of 12 to 18 percent in the lower third of the series control section
Chetomba--have a sand content of more than 15 percent fine sand or coarser in the lower third of the series control section
Dolbee--do not have carbonates within a depth of 125 centimeters
Drummer--do not have carbonates within a depth of 100 centimeters
Dunham--have a rock fragment content of 15 to 70 percent in the lower third of the series control section
Elpaso--do not have carbonates within a depth of 90 centimeters and have a rock fragment content of 1 to 10 percent in the lower third of the series control section
Elvira--do not have carbonates within a depth of 125 centimeters
Garwin--do not have carbonates within a depth of 125 centimeters
Gillett Grove--have a moist bulk density range of 1.6 g/cc to 1.8 g/cc in the lower third of the series control section
Hartsburg--have a sand content that averages less than 5 percent in the particle-size control section
Madelia--do not have carbonates within a depth of 50 centimeters
Marcus--do not have carbonates within a depth of 60 centimeters
Mascoutah--do not have carbonates within a depth of 100 centimeters
Maxfield--do not have carbonates within a depth of 100 centimeters
Maxcreek--do not have carbonates within a depth of 65 centimeters
Maxmore--have a moist bulk density range of 1.75 g/cc to 1.90 g/cc in the lower third of the series control section
Ossian--do not have carbonates within a depth of 100 centimeters
Patton--do not have carbonates within a depth of 100 centimeters
Pella--have stratified materials with a sand content that averages more than 10 percent in the lower third of the series control section
Rushmore--have a moist bulk density range of 1.6 g/cc to 1.8 g/cc in the lower third of the series control section
Sable--do not have carbonates within a depth of 100 centimeters

GEOGRAPHIC SETTING:
Parent material--silty lacustrine sediments
Landform--broad depressions and swales on till plains, moraines, and stream terraces
Slopes--0 to 2 percent
Elevation--200 to 400 meters above sea level
Mean annual air temperature--6 to 10 degrees C
Mean annual precipitation--585 to 965 millimeters
Frost-free period--150 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Harps, Nicollet, Okoboji, and Webster soils.
Harps--are at slightly higher landscape positions on rims of depressions and have a sand content that averages 30 to 55 percent in the particle-size control section
Nicollet--are at higher landscape positions on slightly convex rises and have a sand content that averages 20 to 55 percent in the particle-size control section
Okoboji--are on landscape positions similar to that of the Wacousta soils and have a mollic epipedon 60 to 150 centimeters thick
Webster--are at slightly higher landscape positions on flats and have a sand content that averages more than 15 percent in the particle-size control section

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--very poorly drained--in undrained conditions, a frequently saturated zone occurs at the surface to a depth of 0.3 meters during the wettest periods of 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
Ponding--frequently ponded for long duration

USE AND VEGETATION:
Where drained, these areas are cultivated. The principal crops are corn, soybeans, and small grain. Reed canarygrass commonly dominates partially drained pasture. The native vegetation is herbaceous marsh species tolerant of excessive wetness such as, cattails, bulrushes, giant burreed, giant reed grass and hydrophytic sedges.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Western lake section and Eastern lake section
MLRAs--Central Iowa and Minnesota Till Prairies (103) and Southern Wisconsin and Northern Illinois Drift Plain (95B)
LRR M;--central and north-central Iowa, south-central Minnesota, and southern Wisconsin
Extent--moderate

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Humboldt County, Iowa, 1958.

REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters;
series control section--the zone from the surface of the soil 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 43 centimeters (Ap and A horizons);
cambic horizon--the zone from a depth of 43 to 64 centimeters (Bg horizon);
aquic moisture regime.

The type location was moved because the previous location had been disturbed.

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.

---

National Cooperative Soil Survey
U.S.A.