LOCATION JACWIN IAEstablished Series
TAXONOMIC CLASS: Fine-loamy over clayey, mixed, superactive, mesic Aquic Hapludolls
TYPICAL PEDON: Jacwin loam, on a linear slope of about 1 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 18 centimeters (0 to 7 inches); black (N 2/0) loam; weak fine and medium subangular blocky structure; firm; common very fine and fine roots; common fine moderate continuity tubular pores; neutral; clear wavy boundary.
A1--18 to 33 centimeters (7 to 13 inches); black (N 2/0) loam; moderate fine and medium subangular blocky structure; firm; common very fine and fine roots; common fine moderate continuity tubular pores; neutral; clear wavy boundary. [Combined thickness of the A horizon is 30 to 61 centimeters (12 to 24 inches).]
Bw--33 to 43 centimeters (13 to 17 inches); dark grayish brown (2.5Y 4/2) clay loam; moderate fine and medium subangular blocky structure; firm; common fine roots; common very fine and fine moderate continuity tubular pores; few distinct dark gray (10YR 4/1) organic coats on faces of peds; common fine and medium prominent yellowish brown (10YR 5/6) redoximorphic concentrations; neutral; gradual wavy boundary.
Bk--43 to 61 centimeters (17 to 24 inches); light olive brown (2.5Y 5/4) clay loam; moderate fine and medium subangular blocky structure; firm; common fine roots; common fine moderate continuity tubular pores; common fine and medium rounded pale yellow (2.5Y 8/4) calcium carbonate concretions; common fine and medium distinct olive (5Y 5/4) and common fine and medium prominent yellowish brown (10YR 5/6) redoximorphic concentrations; slightly alkaline; gradual wavy boundary. [Combined thickness of the Bw or Bk horizon is 20 to 36 centimeters (8 to 14 inches).]
2BCk--61 to 94 centimeters (24 to 37 inches); olive yellow (2.5Y 6/6), yellowish brown (10YR 5/6), and gray (2.5Y 6/1) silty clay; moderate medium and coarse subangular blocky structure; very firm; common fine and medium rounded pale yellow (2.5Y 8/4) calcium carbonate concretions; slightly alkaline; gradual wavy boundary. [10 to 36 centimeters (4 to 14 inches) thick]
2Cr--94 to 203 centimeters (37 to 80 inches); light olive brown (2.5Y 5/3), yellowish brown (10YR 5/8), and gray (10YR 6/1) silty clay residuum from calcareous shale; massive; very firm; common fine and medium pale yellow (2.5Y 8/4) carbonate threads; slightly effervescent; slightly alkaline.
TYPE LOCATION: Major Land Resource Area (MLRA) 105; Winneshiek County, Iowa; about 2.5 miles south of Fort Atkinson; about 128 meters (420 feet) west and 791 meters (2595 feet) south of the northeast corner of sec. 29, T. 96 N., R. 9 W.; USGS Saint Lucas quadrangle; lat. 43 degrees 6 minutes 15.8 seconds N and long. 91 degrees 55 minutes 30.4 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon--30 to 61 centimeters (12 to 24 inches)
Depth to carbonates--38 to 91 centimeters (15 to 36 inches)
Depth to residuum from calcareous shale--76 to 102 centimeters (30 to 40 inches)
Clay content of particle-size control section (weighted average)--24 to 30 percent in the loamy glacial sediments and 45 to 60 percent in the residuum
Sand content of particle-size control section (weighted average)--20 to 40 percent in the loamy glacial sediments and 5 to 20 percent in the residuum
A or Ap horizon:
Hue--10YR, 2.5Y, or is neutral
Value--2 or 3
Chroma--0 or 1
Texture--loam, silt loam or silty clay loam
Clay content--22 to 32 percent
Sand content--20 to 50 percent
Reaction--slightly acid or neutral
Some pedons have organic coatings on ped faces with value of 2 or 3 and chroma of 1 or 2 extending below depths of (24 inches)
AB horizon (when present):
Hue--10YR or 2.5Y
Value--2 or 3
Chroma--0 to 2
Texture--silty clay loam, silt loam, or loam
Clay content--22 to 32 percent
Sand content--20 to 50 percent
Reaction--slightly acid or neutral
Bw or Bk horizon:
Hue--10YR or 2.5Y
Value--4 or 5
Chroma--2 to 6
Texture--loam, sandy clay loam or clay loam
Clay content--20 to 32 percent
Sand content--35 to 55 percent
Reaction--slightly acid to slightly alkaline
Redoximorphic features--few to many high chroma
Pedons with high chroma matrix in the B horizon typically have redoximorphic features
2Bk, 2BC, 2BCk, or 2C horizon:
Hue--10YR, 2.5Y, 5Y or 5G
Value--4 to 6
Chroma--1 to 8
Texture--silty clay or clay
Clay content--40 to 60 percent
Sand content--5 to 20 percent
Reaction--neutral or slightly alkaline
Some pedons have a thin, less than (5 inches) thick, layer of sandy loam or loamy sand, directly above the finer textured 2BC horizon
Some pedons have a small amount of fractured limestone interbedded with the materials above the calcareous shale
2Cr horizon:
Hue--10YR, 2.5Y, 5Y, or 5G
Value--4 to 6
Chroma--1 to 8
Texture--silty clay or clay residuum from calcareous shale
Clay content--45 to 60 percent
Sand content--5 to 20 percent
Reaction--slightly alkaline or moderately alkaline
COMPETING SERIES: No other series are in this family.
GEOGRAPHIC SETTING:
Parent material--loamy glacial sediments and in the underlying residuum from calcareous shale
Landform--treads and risers on structural benches
Slopes--0 to 18 percent
Elevation--(600 to 1500 feet) above sea level
Mean annual air temperature--7 to 9 degrees C (45 to 49 degrees F)
Mean annual precipitation--79 to 86 centimeters (31 to 34 inches)
Frost-free period--145 to 170 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Calamine,
Clyde,
Rockton, and
Saude soils.
Calamine--are in landscape positions similar to those of the Jacwin soils, have a paralithic contact within a depth of 152 centimeters (60 inches), and have a seasonally saturated zone within a depth of 0.3 meters (1 foot) in most years
Clyde--are at lower elevations in concave drainageways on interfluves, do not have a clay content of 18 to 38 percent and a sand content of 35 to 65 percent in the lower third of the series control section
Rockton--are at lower elevations on side slopes and have a lithic contact of limestone bedrock within depths of 51 to 102 centimeters (20 to 40 inches)
Saude--are at lower elevations on stream terraces and have a clay content of 2 to 8 percent and rock fragment content of 5 to 30 percent in the lower two thirds of the series control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--somewhat poorly drained--a saturated zone occurs within depths of 0.3 to 1 meter (12 to 40 inches) during the wettest portions of most years and is considered perched
Saturated hydraulic conductivity--moderately high in the loamy glacial sediments and low in the residuum
Surface runoff potential--negligible to medium
USE AND VEGETATION:
Most areas are cultivated. The principal crops are corn, soybeans, oats and legume hay. The native vegetation is big bluestem, little bluestem, switchgrass, other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section(s)--Dissected till plains, Wisconsin driftless section
MLRA(s)--Eastern Iowa and Minnesota Till Prairies (104), Northern Mississippi Valley Loess Hills (105)
LRR M; northeast Iowa and possibly southeastern Minnesota
Extent--small
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Howard County, Iowa, 1969
REMARKS:
Particle-size control section--the zone from a depth of 25 to 100 centimeters (10 to 40 inches) (A1, Bw, Bk, 2BCk, and 2Cr horizons);
series control section--the zone from the surface to a depth of 150 centimeters 0 to 60 inches) (Ap, A1, Bw, Bk, 2BCk, and 2Cr horizons).
Diagnostic horizons and features recognized in this pedon:
mollic epipedon--the zone from the surface to a depth of 33 centimeters (0 to 13 inches) (Ap and A1 horizons);
cambic horizon--the zone from 33 to 61 centimeters (13 to 24 inches) (Bw and Bk horizons);
udic moisture regime.
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomy version--second edition, 1999.
The type location has been moved to better typify the central concept of the series.