LOCATION BROADBROOK CT+MA RIEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, active, mesic Oxyaquic Dystrudepts
TYPICAL PEDON: Broadbrook silt loam - cultivated field. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark brown (10YR 2/2) silt loam, pale brown (10YR 6/3) dry; moderate medium granular structure; very friable; few fine roots; 5 percent gravel; moderately acid; clear wavy boundary. (6 to 10 inches thick)
Bw1--8 to 14 inches; dark yellowish brown (10YR 4/6) silt loam; moderate medium subangular blocky structure; very friable; few fine roots; 5 percent gravel; moderately acid; clear wavy boundary.
Bw2--14 to 25 inches; dark yellowish brown (10YR 4/4) silt loam; moderate medium subangular blocky structure; very friable; 5 percent gravel; moderately acid; gradual wavy boundary. (Combined thickness of the Bw horizon is 14 to 37 inches.)
2Cd--25 to 65 inches; olive brown (2.5Y 4/4) gravelly fine sandy loam; weak medium platy structure; very firm, brittle; 15 percent gravel and cobbles; moderately acid.
TYPE LOCATION: New London County, Connecticut; town of Ledyard, 2,500 feet east northeast of the junction of Connecticut Route 117 and Thomas Road, and 1,000 feet north of Thomas Road; USGS Uncasville topographic quadrangle, latitude 41 degrees 28 minutes 24 seconds N., longitude 72 degrees 1 minute 9 seconds W., NAD 27
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 18 to 40 inches and typically corresponds to the depth to the dense substratum. Depth to bedrock is commonly more than 6 feet. Rock fragments range from 0 to 20 percent by volume in the solum and from 5 to 35 percent in the substratum. Except where the surface layer is stony, the fragments are mostly subrounded gravel and typically make up 60 percent or more of the total rock fragments. Unless limed, reaction ranges from very strongly acid through moderately acid.
The Ap horizon has hue of 7.5YR or 10YR and value and chroma of 2 to 4. Dry value is 6 or more. Undisturbed pedons have a thin A horizon with value of 2 or 3 and chroma of 1 through 3. The Ap or A horizon commonly is silt loam or very fine sandy loam in the fine-earth fraction, but includes loam high in silt. It has weak or moderate granular structure and is friable or very friable.
Some pedons have a thin E horizon below the A horizon. It has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 1 to 3. Texture, structure, and consistence are like the A horizon.
The upper part of the Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 4 to 6. The lower part of the Bw horizon has hue of 7.5YR to 2.5Y, value of 4 or 5, and chroma of 3 to 6. Some pedons have few faint redoximorphic features just above the 2Cd horizon. The Bw horizon is silt loam, very fine sandy loam, or loam with more than 65 percent silt plus very fine sand. It has weak granular or subangular blocky structure, or the horizon is massive. Consistence is friable or very friable.
Some pedons have an E or E' horizon up to 3 inches thick below the B horizon. It has hue of 10YR to 5Y, value of 5 or 6, and chroma of 2 or 3. Typically, it is coarser textured than the overlying horizon.
The 2Cd horizon has hue of 2.5YR to 5Y, value of 4 to 6, and chroma of 2 to 6. It is fine sandy loam or sandy loam in the fine-earth fraction. The horizon has weak or moderate, medium to very thick plates, or it is massive. Consistence is firm or very firm. Some pedons have a thin friable 2C horizon above the 2Cd horizon.
COMPETING SERIES: These are the Paxton and Wethersfield series in the same family. Paxton soils have a B horizon with less than 65 percent silt plus very fine sand. Wethersfield soils have 5YR or redder hue in the B horizon.
GEOGRAPHIC SETTING: Broadbrook soils are nearly level to steep and are on till plains, hills, and drumlins. Slopes range from 0 to 35 percent. The soils formed in silty mantled acid till derived from gneiss, schist, sandstone, conglomerate, and basalt. Mean annual temperature ranges from 45 to 52 degrees F., mean annual precipitation ranges from 37 to 50 inches, and the growing season ranges from 120 to 185 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Paxton and Wethersfield soils and the Agawam, Birchwood, Bridgehampton, Canton, Charlton, Cheshire, Enfield, Hollis, Leicester, Ludlow, Menlo, Merrimac, Montauk, Narragansett, Newport, Rainbow, Ridgebury, Scituate, Stissing, Sutton, Wapping, Watchaug, Whitman, Wilbraham soils and Woodbridge soils. The moderately well drained Rainbow soils are associated in a drainage sequence. Agawam, Enfield, and Merrimac soils are on nearby outwash terraces and are underlain by stratified sand or sand and gravel. Canton and Sutton soils do not have a dense substratum. Hollis soils have bedrock within a depth of 10 to 20 inches. Leicester, Ridgebury, Stissing, and Wilbraham soils are poorly drained. Mansfield, Menlo, and Whitman soils are very poorly drained.
DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is medium to rapid. Permeability is moderate in the solum and slow or very slow in the substratum.
USE AND VEGETATION: Many areas are cleared and used for cultivated crops, hay or pasture. Scattered areas are used for community development. Some areas are wooded. Common trees are red and white oak, hickory, sugar maple, ash, yellow poplar, white pine, and hemlock.
DISTRIBUTION AND EXTENT: Glaciated uplands in Connecticut, Massachusetts, and Rhode Island; MLRAs 144A and 145. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Amherst, Massachusetts
SERIES ESTABLISHED: Hartford County, Connecticut, 1959.
REMARKS: This revision reflects an update of the taxonomic class to the 8th Edition of Soil Taxonomy, 1998 (including the addition of cation exchange activity class to the family).
Broadbrook soils were previously classified as Typic Dystrochrepts, and before that as Typic Fragiochrepts.
Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from 0 to 8 inches (Ap horizon).
2. Cambic horizon - the zone from 8 to 25 inches (Bw horizons).
3. Lithologic discontinuity at a depth of 25 inches.
4. Dense till substratum - the zone from 25 to 65 inches (2Cd horizon).
5.Oxyaquic subgroup based on saturation in one or more sublayers within 100 cm of the mineral surface, for one month or more per year, in 6 out of 10 years.