LOCATION WALFORD IA+MN
Established Series
Rev. TEF-RPD-RJB
06/2015
WALFORD SERIES
The Walford series consists of very deep, poorly and very poorly drained soils formed in loess. These soils are on interfluves or ridgetops on dissected till plains and treads and risers on stream terraces. Slopes range from 0 to 3 percent. Mean annual air temperature is about 10 degrees C (50 degrees F). Mean annual precipitation is about 87 centimeters (34 inches).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Endoaqualfs
TYPICAL PEDON: Walford silt loam, with a slope of about 1 percent, in a cultivated field, at an elevation of 242 meters (794 feet) above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 15 centimeters (0 to 6 inches); very dark gray (10YR 3/1) silt loam, dark gray (10YR 4/1) dry; weak fine and medium granular structure; friable; slightly acid; abrupt smooth boundary. [13 to 23 centimeters (5 to 9 inches) thick]
E1--15 to 23 centimeters (6 to 9 inches); dark grayish brown (10YR 4/2) silt loam; weak thin platy structure; friable; few fine faint dark brown (7.5YR 3/2) redoximorphic concentrations; moderately acid; clear smooth boundary.
E2--23 to 38 centimeters (9 to 15 inches); grayish brown (10YR 5/2) silt loam; weak thin platy structure; friable; few fine distinct brown (7.5YR 4/4) redoximorphic concentrations; moderately acid; clear smooth boundary. [Combined thickness of the E horizon is 8 to 25 centimeters (3 to 10 inches).]
BEg--38 to 56 centimeters (15 to 22 inches); grayish brown (10YR 5/2) silt loam; weak fine and medium subangular blocky structure; friable; few dark reddish brown (5YR 3/2) iron-manganese concretions; many fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; strongly acid; clear smooth boundary. [0 to 20 centimeters (0 to 8 inches) thick]
Btg1--56 to 76 centimeters (22 to 30 inches); light brownish gray (2.5Y 6/2) silty clay loam; weak fine prismatic structure parting to moderate fine subangular blocky; firm; common distinct grayish brown (2.5Y 5/2) clay films on faces of peds; many distinct light gray (10YR 7/2) dry silt coats on faces of peds; many fine prominent strong brown (7.5YR 5/6) redoximorphic concentrations; strongly acid; gradual smooth boundary.
Btg2--76 to 102 centimeters (30 to 40 inches); light brownish gray (2.5Y 6/2) silty clay loam; moderate fine prismatic structure parting to moderate medium subangular blocky; firm; common distinct grayish brown (2.5Y 5/2) clay films on faces of peds; common prominent dark reddish brown (5YR 3/2) iron-manganese concretions; many coarse prominent strong brown (7.5YR 5/6) redoximorphic concentrations; moderately acid; gradual smooth boundary.
Btg3--102 to 127 centimeters (40 to 50 inches); about 80 percent light brownish gray (2.5Y 6/2) and about 20 percent strong brown (7.5YR 5/6) silty clay loam; weak medium prismatic structure; firm; common distinct grayish brown (2.5Y 5/2) clay films on faces of peds; moderately acid; gradual smooth boundary. [Combined thickness of the Btg horizon is 40 to 90 centimeters (16 to 35 inches).]
BCg--127 to 160 centimeters (50 to 63 inches); about 60 percent light brownish gray (2.5Y 6/2) and about 40 percent strong brown (7.5YR 5/6) silty clay loam; weak coarse prismatic structure; firm; many dark reddish brown (5YR 3/2) iron-manganese concretions; moderately acid; gradual smooth boundary. [0 to 30 centimeters (0 to 12 inches) thick]
Cg--160 to 203 centimeters (63 to 80 inches); about 60 percent grayish brown (2.5Y 5/2) and about 40 percent light olive brown (2.5Y 5/3) silt loam; massive; friable; common medium prominent strong brown (7.5YR 4/6) irregular masses of iron-manganese; moderately acid.
TYPE LOCATION: Major Land Resource Area (MLRA) 108C-Illinois and Iowa Deep Loess and Drift, West Central Part; Cedar County, Iowa subset; about 3 miles northwest of the village of Sunbury; about 23 meters (75 feet) west and 595 meters (1,950 feet) north of the southeast corner of section 27, T. 80 N., R. 1 W.; USGS Bennett quadrangle; lat. 41 degrees 42 minutes 16.3 seconds N. and long. 90 degrees 56 minutes 16.8 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Depth to carbonates--greater than 150 centimeters (greater than 59 inches)
Clay content of the particle-size control section (weighted average)--24 to 32 percent
Sand content of the particle-size control section (weighted average)--less than 15 percent
Rock fragment content--0 percent
Ap or A horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silt loam
Clay content--15 to 25 percent
Sand content--less than 15 percent
Reaction--slightly acid or neutral
E horizon:
Hue--10YR or 2.5Y
Value--4 to 6
Chroma--1 or 2
Texture--silt loam
Clay content--18 to 26 percent
Sand content--less than 15 percent
Reaction--strongly acid or moderately acid
BEg horizon (when present):
Hue--10YR to 5Y
Value--5 or 6
Chroma--1 or 2
Texture--silt loam
Clay content--18 to 26 percent
Sand content--less than 15 percent
Reaction--strongly acid or moderately acid
Btg horizon:
Hue--10YR to 5Y
Value--5 or 6
Chroma--1 or 2
Texture--silty clay loam
Clay content--24 to 32 percent
Sand content--less than 15 percent
Reaction--strongly acid or moderately acid
Some pedons have subhorizons with a clay content of up to 35 percent
BCg horizon:
Hue--2.5Y or 5Y
Value--5 or 6
Chroma--1 or 2
Texture--silty clay loam or silt loam
Clay content--25 to 32 percent
Sand content--less than 15 percent
Reaction--strongly acid or moderately acid
Cg horizon:
Hue--2.5Y or 5Y
Value--5 or 6
Chroma--1 or 2
Texture--silt loam
Clay content--18 to 27 percent
Sand content--5 to 20 percent
Reaction--moderately acid to slightly alkaline
Some pedons have sandy materials below a depth of 150 centimeters (59 inches)
COMPETING SERIES: These are the
Ansgar,
Blanchester,
Coppock,
Cory, and
Newberry series.
Ansgar--have a sand content of more than 15 percent in the lower third of the series control section
Blanchester--have a rock fragment content of 2 to 10 percent in the lower third of the series control section
Coppock--have albic horizons 36 to 61 centimeters (14 to 24 inches) thick
Cory--are in areas that have a mean annual and a mean annual precipitation range of 102 to 112 centimeters (40 to 44 inches) - see remarks
Newberry--have a clay content of 35 to 45 percent and a sand content of 15 to 40 percent in the lower third of the series control section
GEOGRAPHIC SETTING:
Parent material--loess
Landform--interfluves or ridgetops on dissected till plains and treads and risers on stream terraces
Slope--0 to 3 percent
Elevation--213 to 427 meters (700 to 1,400 feet) above sea level
Mean annual air temperature--8 to 12 degrees C (47 to 54 degrees F)
Mean annual precipitation--79 to 94 centimeters (31 to 37 inches)
Frost-free period--165 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS: Members of the typical catena include the
Atterberry,
Downs,
Greenbush, New
Vienna, and
Sperry soils.
Atterberry--are at higher elevations on interfluves and have a frequently saturated zone within depths of 0.3 to 0.9 meter (1 to 3 feet) in normal years
Downs--are at lower elevations on side slopes and do not have a frequently saturated zone within a depth of 1.8 meters (6 feet) in normal years
Greenbush--are at lower elevations on side slopes and are at higher elevations on interfluves and have a frequently saturated zone within depths of 1.2 to 1.8 meters (4 to 6 feet) in normal years
New
Vienna--are at lower elevations on side slopes and are at higher elevations on interfluves and have a frequently saturated zone within depths of 0.7 to 1.2 meters (2.5 to 4 feet) in normal years
Sperry--are at lower elevations in depressions and have a clay content of 35 to 45 percent in the particle-size control section
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly or very poorly drained--a frequently saturated zone occurs within a depth of 0.3 meter (0 to 1 foot) during the wettest periods of normal years and is considered apparent
Saturated hydraulic conductivity--moderately high
Surface runoff potential--negligible to low
Ponding--occasionally ponded up to 0.3 meter (1 foot) in depth for brief to long periods during the months of November to May in normal years from precipitation events and snowmelt
USE AND VEGETATION:
Drained areas are cultivated. The principal crops are corn, soybeans, small grains and hay. A few areas are in open woods. The native vegetative cover is a mixed herbaceous and woody community commonly inhabited with Green Ashes, American Elms, Common Hackberries, Eastern Cottonwoods, American Sycamores, Silky Dogwoods, Black Willows, Wild Black Currants, Riverbank Grapes, Grays Sedges, Hop Sedges, Virginia Wildryes, Stiff Bedstraws, White Avens, Wood Nettles, False Nettles, Canadian Clearweeds, and Common Bonesets.
DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Dissected till plains
MLRA--Illinois and Iowa Deep Loess and Drift (108)
LRR M; southeastern Iowa
Extent--moderate
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Iowa County, Iowa, 1946
REMARKS:
Particle-size control section--the zone from a depth of 56 to 106 centimeters (22 to 42 inches) (Btg1, Btg2, and Btg3 horizons);
Series control section--the zone from the surface to a depth of 160 centimeters (0 to 63 inches) (Ap, E1, E2, BEg, Btg1, Btg2, Btg3, and BCg horizons).
Diagnostic horizons and features recognized in this pedon:
ochric epipedon--the zone from the surface to a depth of 38 centimeters (15 inches) (Ap, E1, and E2 horizons);
albic horizon--the zone from a depth of 15 to 38 centimeters (6 to 15 inches) (E1 and E2 horizons);
argillic horizon--the zone from a depth of 56 to 127 inches (22 to 50 inches) (Btg1, Btg2, and Btg3 horizons);
aquic moisture regime.
The differentiae of the Coppock and Cory series to Walford series needs further study.
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.
ADDITIONAL DATA:
Laboratory data--Iowa State University, Ames, Iowa
National Cooperative Soil Survey
U.S.A.