LOCATION WEBSTER IA+MN

Established Series
Rev. CSF-CAJ-JJB
04/2014

WEBSTER SERIES

The Webster series consists of very deep, poorly drained, moderately permeable soils formed in glacial till or local alluvium derived from till on uplands. Slope ranges from 0 to 3 percent. Mean annual air temperature is about 48 degrees F, and mean annual precipitation is about 30 inches.

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

TYPICAL PEDON: Webster silty clay loam on a concave slope of about 1 percent gradient 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 subangular blocky structure; friable; pH 6.4 (slightly acid); clear smooth boundary.

A--20 to 41 centimeters; black (N 2/0) silty clay loam, very dark gray (10YR 3/1) dry; few fine faint very dark grayish brown (2.5Y 3/2) redox depletions; weak medium subangular blocky structure; friable; about 3 percent gravel; few worm casts; pH 6.5 (slightly acid); clear smooth boundary. (Combined thickness of the A horizons is 35 to 61 centimeters.)

BAg--41 to 53 centimeters; dark gray (5Y 4/1) clay loam; few fine distinct dark grayish brown (2.5Y 4/2) redox depletions; weak fine subangular blocky structure; friable; continuous very dark gray (5Y 3/1) coatings on faces of peds; many roots; many pores; pH 6.9 (neutral); gradual smooth boundary. (0 to 15 centimeters thick)

Bg1--53 to 66 centimeters; olive gray (5Y 5/2) clay loam; common fine faint dark gray (5Y 4/1) redox depletions; weak fine subangular blocky structure; friable; discontinuous very dark gray (10YR 3/1) coatings on faces of peds; many roots; many fine pores and worm holes; few fine dark concretions (iron and manganese oxides); neutral; clear smooth boundary.

Bg2--66 to 81 centimeters; light olive gray (5Y 6/2) clay loam; weak fine subangular blocky structure; friable; discontinuous dark gray (5Y 4/1) coatings on faces of peds; few roots; many fine and medium pores; few dark concretions (iron and manganese oxides); few very dark gray (10YR 3/1) organic coatings along root channels and cleavage planes; pH 7.5 (neutral); gradual smooth boundary. (Combined thickness of the Bg horizons is 18 to 66 centimeters.)

BCg--81 to 102 centimeters; light olive gray (5Y 6/2) loam; few fine prominent yellowish brown (10YR 5/6) redox concentrations; weak fine subangular blocky structure; friable; few roots; few white masses and streaks of calcium carbonate in the lower part; pH 7.7 (slightly alkaline); clear smooth boundary. (0 to 23 centimeters thick)

Cg--102 to 200 centimeters; light olive gray (5Y 6/2) loam; common medium prominent yellowish brown (10YR 5/6) redox concentrations; massive; friable; about 3 percent gravel; strongly effervescent; pH 7.7 (slightly alkaline).

TYPE LOCATION: Major Land Resource Area (MLRA) 103 - Central Iowa and Minnesota Till Prairies; Hamilton County, Iowa; about 1 mile south of Webster City; 700 feet west and 1,480 feet north of the southeast corner of sec. 12, T. 88 N., R. 26 W.; fifth principal meridian; USGS Webster City, Iowa quadrangle, latitude 42 degrees 26 minutes 45 seconds N., longitude 93 degrees 49 minutes 06 seconds W.

RANGE IN CHARACTERISTICS:

Thickness of the mollic epipedon - 35 to 61 centimeters
Depth to carbonates - 61 to 107 centimeters
Clay content of the particle-size control section (weighted average) - 10-39 percent
Sand content of the particle -size control section (weighted average - 16-46 percent
Coarse fragment - 1-15 percent throughout the profile

Ap or A horizon:
Hue - 10YR
Value - 2 or 3
Chroma - 0 or 1
Texture: clay loam, loam or silty clay loam
Clay content: 29 to 39 percent
Sand content: 16 to 33 percent
Rock fragment content: 1 to 15 percent
Reaction: 5.6 to 7.3
Thickness: 35 to 61 centimeters

Bg horizon:
Hue - 5Y or 2.5Y
Value - 4 or 5
Chroma - 1 or 2
Texture - clay loam, loam or silty clay loam
Clay content - 10 to 34 percent
Sand content - 18 to 46 percent
Reaction - 6.6 to 7.8
Thickness - 18 to 66 centimeters

Some pedons have a BCg horizon

Cg horizon:
Hue - 5Y or 2.5Y
Value - 4 or 5
Chroma - 1 or 2
Texture - loam, clay loam, sandy loam or fine sandy loam
Clay content - 10 to 33 percent
Sand content - 25 to 60 percent
Reaction - 7.4 to 8.4

COMPETING SERIES:
Clyde -leached profile to at least 114 centimeters and have stratified substratum with higher fragment content
Faxon - have a lithic contact within a depth of 100 centimeters
Kossuth - have carbonates within a depths of 66 centimeters and do not have rock fragments in the upper third of the series control section
Letri - have carbonates within a depth of 75 centimeters
Marengo - has carbonates at 102 to 200 centimeters, has firm consistence, and has coarse fragments mostly of sandstone, siltstone and shale
Mound Creek - has a lithic contact within 50 to 100 centimeters
Reddick - has a firm consistence in the B and C horizons and has a 2 material with a higher clay and lower sand content
Selma - have a clay content that averages less than 15 percent and have a sand content of more than 50 percent in the lower third of the series control section
Selmass - have a sand content that averages more than 80 percent in the lower third of the series control section
Tripoli - has a moist bulk density of 1.75 g/cc to 1.90 g/cc within depths of 46 to 75 centimeters
Wolcott - have a moist bulk density of less than 1.60 g/cc in the lower third of the series control section

GEOGRAPHIC SETTING:
Parent material - calcareous glacial till
Landform - depressions or flats on till plains or moraines
Slopes - 0 to 3 percent
Elevation - 210 to 560 meters above sea level
Mean annual air temperature - 6 to 11 degrees C
Frost free period - 140 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Canisteo - are on similar landscape positions but have carbonates higher in the profile
Clarion, Nicollet - lack gleyed B horizons and are on more convex landscape positions
Glencoe - has saturated conditions closer to the surface
Harps - highly calcareous and occur on rims of depressions
Okoboji - has thicker epipedons with less sand and more clay
Wacousta - has thinner A horizons

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class - poorly drained - a saturated zone occurs within depths of 0 to 20 centimeters during the wettest period in normal years in natural conditions
Saturated hydraulic conductivity - 1.41 to 14.11 micrometers per second throughout

USE AND VEGETATION: Largely cultivated and cropped intensively to corn and soybeans. Small grain and hay are other major crops. Reed canarygrass commonly dominates partially drained pasture. Native vegetation is predominantly wet-site tall prairie species such as prairie cordgrass, switchgrass, big bluestem, wooly sedge, giant goldenrod and Canada goldenrod.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic section--Western lake section
MLRA--Central Iowa and Minnesota Till Prairie (103)
LRR K and LRR M; Iowa and Minnesota
Extent -- Extensive

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

SERIES ESTABLISHED: Clay County, Iowa, 1916.

REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - the zone from the surface of the soil to a depth of 16 inches (Ap and A horizon); Cambic horizon - the zone from a depth of 16 to 40 inches (BAg, Bg1, Bg2 and BCg horizons); aquic moisture regime based on low chroma colors below the mollic epipedon.

The concepts of moderately coarse and moderately fine substratum phases were established by the mlra-103 steering committee. The Des Moines Lobe till gets sandier and contains less clay as one progresses south along the path of the Des Moines advance.

Competing series not updated as of this edit.

National Cooperative Soil Survey
U.S.A.