LOCATION WILBRAHAM CT+MA
Established Series
Rev. MFF-SMF-DCP
11/2016
WILBRAHAM SERIES
The Wilbraham series consists of poorly drained loamy soils formed in red lodgment till. These soils are very deep to bedrock and moderately deep to a densic contact. They are nearly level to gently sloping soils in drainageways and depressions of hills and drumlins. Slope ranges from 0 to 8 percent. Saturated hydraulic conductivity is moderately high in the surface layer and subsoil and low or moderately low in the dense substratum. Mean annual temperature is about 9 degrees C, and mean annual precipitation is about 1175 mm.
TAXONOMIC CLASS: Coarse-loamy, mixed, active, nonacid, mesic Aeric Epiaquepts
TYPICAL PEDON: Wilbraham silt loam, on a 2 percent slope, in a wooded area adjacent to an abandoned pasture. (Colors are for moist soil unless otherwise indicated.)
Ap--0 to 20 cm; dark brown (10YR 3/3) silt loam; weak medium granular structure; friable; many fine roots; 5 percent gravel; moderately acid; clear smooth boundary. (5 to 32 cm thick)
Bw1--20 to 48 cm; reddish brown (5YR 4/3) silt loam; weak medium subangular blocky structure; friable; few fine roots; 10 percent gravel; common medium prominent pinkish gray (7.5YR 6/2) iron depletions and common fine distinct strong brown (7.5YR 5/6) iron concentrations; strongly acid; gradual wavy boundary.
Bw2--48 to 64 cm; reddish brown (5YR 4/4) silt loam; weak medium subangular blocky structure; friable; few fine roots; 10 percent gravel and cobbles; common medium distinct pinkish gray (7.5YR 6/2) iron depletions and common medium prominent strong brown (7.5YR 5/6) iron concentrations; strongly acid; clear wavy boundary. (Combined thickness of the Bw horizons is 30 to 86 cm.)
Cd--64 to 155 cm; reddish brown (5YR 4/4) gravelly loam; massive with weak thick plate-like divisions; very firm; common fine very dark grayish brown (10YR 3/2) manganese concentrations on some plates and rock fragments; 15 percent gravel and cobbles; common fine distinct pinkish gray (7.5YR 6/2) iron depletions and common fine distinct dark yellowish red (5YR 4/6) masses of iron accumulation; strongly acid.
TYPE LOCATION: New Haven County, Connecticut; town of Wallingford, 500 feet east of North Branford Road, and 1,000 feet south of Whirlwind Hill Road. USGS Wallingford, CT topographic quadrangle; latitude 41 degrees 25 minutes 50.91 seconds N. and longitude 72 degrees 45 minutes 11.15 seconds W., WGS84.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 50 to 90 cm. The depth to a densic contact commonly is 50 to 90 cm. Depth to bedrock is commonly more than 180 cm. Rock fragments range from 5 to 30 percent by volume in the A horizon, 5 to 40 percent in the B horizon, and from 5 to 50 percent in the Cd horizon. Except where the surface is stony, the fragments are mostly subrounded gravel and typically make up 60 percent or more of the total rock fragments with the remainder consisting of cobbles or stones. Unless limed, reaction ranges from very strongly acid to moderately acid in the surface layer, and from strongly acid to neutral in the subsoil and substratum.
The O horizon, where present, is commonly muck and may include mucky peat or peat. O horizons are more common in the northern part of the series geographic extent and range from 0 to 10 cm in thickness.
The A horizon has hue of 5YR to 10YR, value of 2 to 4, and chroma of 1 to 3. Disturbed pedons have an Ap horizon with value of 2 to 4 and chroma of 2 or 3. The A or Ap horizon is silt loam, loam, mucky silt loam or mucky loam in the fine-earth fraction. It has weak or moderate granular structure and is friable or very friable. Some A horizons contain iron/manganese concentrations and or fine manganese concretions.
Some pedons have a thin Bg horizon with a value of 4 to 6 and chroma of 1 or 2.
The upper part of the Bw horizon has hue of 5YR to 10YR, value of 3 to 6, and chroma of 3 or 4. The lower part of the Bw horizon has hue of 2.5YR to 7.5YR, value of 3 to 5, and chroma of 3 to 6. The Bw horizon has iron depletions and or iron concentrations throughout, often including fine manganese concretions. It is loam, silt loam, or very fine sandy loam in the fine-earth fraction. The horizon has weak subangular blocky structure or weak plate-like divisions. Consistence is friable or very friable.
Some pedons have a BC horizon with properties similar to the lower Bw horizon.
The Cd horizon has hue of 10R to 7.5YR, value of 3 to 6, chroma of 2 to 6, and it has redoximorphic features. Texture is loam, silt loam, very fine sandy loam, fine sandy loam, sandy loam or coarse sandy loam in the fine-earth fraction. It is massive and may have weak or moderate, medium to very thick plates of geogenic origin. Consistence is firm or very firm.
COMPETING SERIES:
Painesville,
Punsit and
Sun soils are currently in the same family. Painesville soils are formed in glaciolacustrine sediments and contain free carbonates in the profile. Punsit soils formed in glacial till derived from slate, phylite, shale, and schist and have hues of 10YR or yellower throughout. Sun soils formed in glacial till high in limestone and sandstone and contain free carbonates in the profile.
GEOGRAPHIC SETTING: Wilbraham soils are nearly level to gently sloping and are in depressions and drainageways on glaciated hills and drumlins. Slope commonly is less than 5 percent, but the range includes 0 to 8 percent. The soils formed in red lodgment till derived mainly from reddish sandstone, shale, and conglomerate with some basalt. Mean annual temperature ranges from 5 to 12 degrees C., mean annual precipitation ranges from 910 to 1340 mm, and the growing season ranges from 130 to 185 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Berlin,
Birchwood,
Branford,
Broadbrook,
Cheshire,
Ellington,
Hartford,
Holyoke,
Ludlow,
Manchester,
Menlo,
Narragansett,
Penwood,
Poquonock,
Rainbow,
Wapping,
Watchaug,
Wethersfield, and
Yalesville soils on nearby landscapes. The well drained Wethersfield, moderately well drained Ludlow, and the very poorly drained Menlo soils are associated in a drainage sequence. Wethersfield soils are on convex landform positions and do not have aquic conditions in the upper part. Ludlow soils are found on slightly higher areas and have aquic conditions in the solum starting below a depth of 30 cm. Menlo soils are on low-lying areas and have a mollic epipedon and aquic conditions throughout. The Berlin soils are on lacustrine terraces. Birchwood and Poquonock soils are better drained and have a sandy over loamy particle-size control section. Branford, Ellington, Hartford, Manchester, and Penwood soils are on nearby outwash terraces and are underlain by stratified sand and gravel. Broadbrook, Cheshire, and Narragansett soils are well drained. Holyoke and Yalesville soils have bedrock within depths of 25 to 50 and 50 to 100 cm, respectively. Rainbow soils are moderately well drained. Wapping and Watchaug soils do not have dense substratum.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained. Surface runoff is slow. Saturated hydraulic conductivity is moderately high in the solum and low or moderately low in the dense substratum. Wilbraham soils have a water table at or near the surface during wetter periods of the year (typically late fall through spring). They have an aquic moisture regime, but do not always exhibit the low chroma matrix colors required for Aquepts due to red parent materials that retain high chroma color even in reducing conditions. Reducing conditions in the upper part of the soil are inferred based on positive reaction for ferrous iron using the alpha,alpha-dipyridyl field test during periods of saturation and ferric iron removal on Indicator of Reduction is Soils (IRIS) tubes.
USE AND VEGETATION: Most areas are wooded. Cleared areas are used for hay or pasture and, if drained, are used for cultivated crops. A few areas are used for community development. Common trees are red maple, elm, ash, and pin oak. Understory plants include skunk cabbage, jewelweed, reed canarygrass, spice bush, alder, jack in the pulpit, winterberry, sedges, and rushes.
DISTRIBUTION AND EXTENT: Low-lying areas on Late Wisconsin glaciated uplands in the Connecticut River Valley of Connecticut and Massachusetts; MLRA 145 along with very limited areas of MLRA 144A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts
SERIES ESTABLISHED: Hartford County, Connecticut, 1959.
REMARKS: This revision updates the taxonomic classification of the series from Aquic Dystrudepts to Aeric Epiaquepts after extensive study of water tables and reducing conditions. Wilbraham soils formed in areas of red parent materials that can be problematic for hydric and wetland soil determinations and have a color change propensity index (CCPI) of less than 30. Hydric soil indicator F21, Red Parent Materials, was developed for use in areas of problematic red parent material and is approved for use in MLRA 145 for materials with CCPI values below 30.
Some pedons historically described as Wilbraham have a densic contact within 40 to 50 cm of the mineral soil surface.
Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from 0 to 20 cm (Ap horizon).
2. Cambic horizon - the zone from 20 to 64 cm (Bw1 and Bw2 horizons).
3. Aquic conditions - the zone from 20 to 64 cm (Bw1 and Bw2 horizons).
4. Aquepts suborder - Positive reaction for ferrous iron using alpha,alpha-dipyridyl during periods of saturation in the zone from 20 to 64 cm (Bw1 and Bw2 horizons).
5. Episaturation - above the densic contact (Ap, Bw1, and Bw2 horizons)
5. Densic materials - the zone from 64 to155 cm (Cd horizon).
6. Particle-size class - averages coarse-loamy in the control section from 25 to 64 cm.
ADDITIONAL DATA: Laboratory characterization data for Wilbraham and similar soils is available through the National Cooperative Soil Survey Soil Characterization Database: http://ncsslabdatamart.sc.egov.usda.gov/
National Cooperative Soil Survey
U.S.A.