LOCATION DOUDS IAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludalfs
TYPICAL PEDON: Douds loam, on a convex slope of 10 percent, in a hayfield. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 centimeters; dark grayish brown (10YR 4/2) loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable; many fine roots; moderately acid; abrupt smooth boundary.
BE--20 to 36 centimeters; brown (10YR 5/3) loam, pale brown (10YR 6/3) dry; weak thin platy structure parting to weak very fine subangular blocky; friable; common fine roots; common distinct dark grayish brown (10YR 4/2) organic coats on all faces of peds; moderately acid; clear smooth boundary.
Bt1--36 to 59 centimeters; yellowish brown (10YR 5/4) clay loam; weak fine subangular blocky structure; friable; common fine roots; common distinct dark yellowish brown (10YR 4/4) clay films on all faces of peds; few distinct light gray (10YR 7/1) dry silt coats on all faces of peds; moderately acid; clear smooth boundary.
Bt2--59 to 86 centimeters; yellowish brown (10YR 5/4) clay loam; moderate medium subangular blocky structure; friable; common fine roots; common distinct dark yellowish brown (10YR 4/4) clay films on all faces of peds; common distinct light gray (10YR 7/1) dry silt coats on all faces of peds; very strongly acid; clear smooth boundary.
Bt3--86 to 123 centimeters; strong brown (7.5YR 5/6) and yellowish brown (10YR 5/4) clay loam; moderate medium subangular blocky structure; friable; common fine roots; common distinct brown (7.5YR 4/4) clay films on all faces of peds; common distinct light gray (10YR 7/1) dry silt coats on all faces of peds; about 5 percent fine gravel; very strongly acid; clear smooth boundary.
BC--123 to 163 centimeters; yellowish brown (10YR 5/6)and strong brown (7.5YR 5/6) clay loam stratified with thin (5 to 25 mm) lenses of sandy clay loam; moderate medium prismatic structure; friable; few very fine roots; common very pale brown (10YR 8/3) dry sand coats on vertical faces of peds; few prominent black (10YR 2/1)iron and manganese concretions; common fine distinct brown (7.5YR 4/4) redoximorphic concentrations; common fine prominent light brownish gray (10YR 6/2) redoximorphic depletions; about 5 percent fine and medium gravel; very strongly acid; clear smooth boundary.
C1--163 to 188 centimeters; yellowish brown (10YR 5/6) clay loam stratified with thin (5 to 25 mm) lenses of sandy clay loam and loam; massive; firm; common very pale brown (10YR 8/3)dry sand coats on strata; common fine black (10YR 2/1) iron and manganese concretions; common fine distinct strong brown (7.5YR 4/6) redoximorphic concentrations; common fine prominent light brownish gray (10YR 6/2) redoximorphic depletions; about 7 percent fine and medium gravel; strongly acid; gradual smooth boundary.
C2--188 to 200 centimeters; yellowish brown (10YR 5/6) clay loam stratified with thin (5 to 25 mm) lenses of loam; massive; firm; few prominent black (10YR 2/1) iron and manganese concretions; common fine faint strong brown (7.5YR 4/6) redoximorphic concentrations; common fine prominent light brownish gray (10YR 6/2) redoximorphic depletions; about 10 percent fine and medium gravel; moderately acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 108C-Illinois and Iowa Deep Loess and Drift, West-Central Part, Washington County, Iowa subset; about 4 miles west and 3 miles south of West Chester; located about 620 feet east and 1,378 feet south of the northwest corner of section 15, T. 75 N., R. 9 W; USGS Keota topographic quadrangle; lat. 41 degrees 18 minutes 18 seconds N. and long. 91 degrees 53 minutes 08 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to stratified materials--75 to 185 centimeters
Depth to carbonates--greater than 200 centimeters
Clay content in the particle size control section (weighted average)--22 to 32 percent
Sand content in the particle size control section (weighted average)--30 to 40 percent
A horizon:
Hue--10YR
Value--3
Chroma--1 or 2
Texture--loam or silt loam
Clay content--20 to 26 percent
Sand content--5 to 40 percent
Rock fragment content--0 percent
Reaction--pH 5.1 to 7.3
Thickness--0 to 20 centimeters
Ap horizon:
Hue--10YR
Value--4 or 5
Chroma--2 to 4
Texture--loam, silt loam, silty clay loam, or clay loam
Clay content--20 to 32 percent
Sand content--5 to 40 percent
Rock fragment content--0 percent
Reaction--pH 5.1 to 7.3
Thickness--0 to 25 centimeters
E horizon:
Hue--10YR
Value--4 or 5
Chroma--2 or 3
Texture--loam or silt loam
Clay content--20 to 26 percent
Sand content--5 to 40 percent
Rock fragment content--0 percent
Reaction--pH 5.1 to 7.3
Thickness--0 to 20 centimeters
BE horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--loam or clay loam
Clay content--20 to 32 percent
Sand content--30 to 45 percent
Rock fragment content--0 percent
Reaction--pH 5.1 to 7.3
Thickness--0 to 20 centimeters
Bt horizon:
Hue--7.5YR or 10YR
Value--4 or 5
Chroma--4 to 8
Texture--loam, clay loam, sandy clay loam, or sandy loam
Clay content--15 to 35 percent
Sand content--30 to 60 percent
Rock fragment content--2 to 15 percent
Reaction--pH 4.5 to 6.0
Thickness--50 to 127 centimeters
BC and C horizons:
Hue--7.5YR to 2.5Y
Value--4 to 6
Chroma--2 to 8
Texture--loam, clay loam, sandy loam, fine sandy loam, or sandy clay loam, or is stratified with these textures
Clay content--10 to 30 percent
Sand content--40 to 80 percent
Rock fragment content--2 to 15 percent
Reaction--pH 4.5 to 6.0
Thickness of the BC horizon--15 to 30 centimeters
These horizons have redoximorphic features
COMPETING SERIES: These are the
Bluemount,
Grellton,
Kendallville,
Kliever,
Letort,
Lindley,
Mandeville,
McHenry,
Mifflin,
Nodine,
Norden,
Ott,
Pecatonica,
Plumcreek,
Renova,
Rockbridge,
Theresa,
Westville,
Whalan, and
Wykoff series.
Bluemount--have a lithic contact within a depth of 100 centimeters
Grellton--do not have redoximorphic features within the series control section
Kendallville--have carbonates within a depth of 100 centimeters
Kliever--do not have stratified materials in the lower third of the series control section
Letort--do not have stratified materials in the lower third of the series control section
Lindley--do not have stratified materials in the lower third of the series control section
Mandeville--have a paralithic contact within a depth of 100 centimeters
McHenry--have carbonates within a depth of 127 centimeters
Mifflin--have a lithic contact within a depth of 140 centimeters
Nodine--have stratified materials within a depth of 50 centimeters
Norden--have a paralithic contact within a depth of 100 centimeters
Ott--have a paralithic or lithic contact within a depth of 100 centimeters
Pecatonica--have a sand content that averages less than 15 percent in the upper one-fourth of the series control section
Plumcreek--do not have rock fragments in the series control section
Renova--have carbonates within a depth of 150 centimeters
Rockbridge--have a paralithic contact within a depth of 200 centimeters
Theresa--have carbonates within a depth of 100 centimeters
Westville--have a subhorizon with a matrix hue or clay film color of 5YR in the middle part of the series control section
Whalan--have a lithic contact within a depth of 100 centimeters
Wykoff--do not have redoximorphic features within the series control section
GEOGRAPHIC SETTING:
Parent material--alluvial sediments derived from glaciers
Landform--risers of high stream terraces that border valleys of major streams and their tributaries
Slope--9 to 60 percent
Elevation--130 to 340 meters above sea level
Mean annual air temperature--8 to 13 degrees C
Mean annual precipitation--840 to 1,040 millimeters
Frost-free period--170 to 215 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Colo,
Galland,
Lindley, and
Nodaway soils.
Colo--are in lower landscape positions on base slopes and floodplains and have mollic epipedons 75 to 100 centimeters thick
Galland--are in higher landscape positions on treads and have a clay content that averages 38 to 45 percent in the upper part of the particle-size control section
Lindley--are in higher landscape positions on uplands and are not stratified in the lower part of the series control section
Nodaway--are in lower landscape positions on floodplains and have sand content that averages less than 15 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained--a frequently saturated zone occurs between depths of 1.0 and 1.8 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--1.0 to 10 micrometers per second in the upper part of the profile and 1.00 to 100 micrometers per second in the lower part
USE AND VEGETATION:
Most gently sloping areas are cultivated. Some steeply sloping areas are pastured. The principal crops are corn, soybeans, small grains, and hay. The native vegetation is oak-hickory forest.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRAs--Illinois and Iowa Deep Loess and Drift (108); Iowa and Missouri Heavy Till Plain (109); and Central Mississippi Valley Wooded Slopes (115)
LRR M; southern Iowa and possibly northern Missouri
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana; MLRA SSO 10-12 (Fairfield, Iowa).
SERIES ESTABLISHED: Van Buren County, Iowa, 1960.
REMARKS:
Particle-size control section--the zone from a depth of 36 to 86 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:
ochric epipedon--the zone from the surface of the soil to a depth of 36 centimeters (Ap and BE horizons);
argillic horizon--the zone from a depth of 36 to 123 centimeters (Bt1, Bt2, and Bt3, horizons);
udic moisture regime.
These areas are distinctly higher in elevation than the modern flood plains but are lower in elevation than the adjacent late Wisconsin recent dissection slopes.
Depth to stratified material decreases as gradient increases on convex slopes.
This update relocates the type location to better represent the central concept of the Douds series.
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.