The following is a map unit description from the "Soil Survey of Barnstable County, Massachusetts (Fletcher, 1993)"
PvC-Plymouth-Barnstable complex, rolling, very bouldery. These undulating and rolling, very deep, excessively drained and well drained soils are on the side slopes of moraines. Stones and boulders cover 1 to 3 percent of the surface (fig. 13). Slopes range from 3 to 15 percent. The soils make up about 1.1 percent (2,811 acres) of the survey area. They are mapped mainly in the Plymouth-Barnstable-Nantucket general soil map unit. Areas are irregular in shape and generally range from 20 to 600 acres in size. They are about 55 percent Plymouth soil, 20 percent Barnstable soil, and 25 percent other soils. The soils occur as areas so intricately mixed or so small that separating them in mapping is not practical.
Typically, the surface of the Plymouth soil is covered with an organic layer. This layer is about 1 inch of loose, undecomposed pine needles, leaves, and twigs and 1 inch of partly decomposed and well decomposed organic material. The surface layer is about 3 inches thick. It is black, very friable loamy coarse sand in the upper 1 inch and gray, loose coarse sand in the lower 2 inches. The subsoil is about 26 inches thick. In sequence downward, it is 1 inch of dark brown, very friable gravelly loamy coarse sand; 5 inches of strong brown, very friable gravelly loamy coarse sand; 1 0 inches of yellowish brown, very friable gravelly loamy coarse sand; and 10 inches of light yellowish brown, loose gravelly coarse sand. The substratum extends to a depth of 65 inches or more. It is light brownish gray, loose gravelly coarse sand in the upper 12 inches and pale brown, loose coarse sand in the lower part.
covered with an organic layer. This layer is about 1 inch of undecomposed pine needles, leaves, and twigs and 2 inches of partly decomposed and well decomposed organic material. The surface layer is dark gray, very friable sandy loam about 1 inch thick. The subsoil is friable sandy loam about 22 inches thick. The upper 1 inch is dark brown, the next 7 inches is yellowish brown, and the lower 14 inches is light olive brown. The substratum to a depth of 65 inches or more is light yellowish brown, loose coarse sand.
Included with these soils in mapping are small areas of Carver, Hinckley, and Nantucket soils. Also included are areas where slopes are less than 3 percent or more than 15 percent and small, isolated areas that do not have boulders on the surface. Included soils make up about 25 percent of this unit.
Permeability is rapid in the subsoil of the Plymouth soil and very rapid in the substratum. Available water capacity is low. Depth to the seasonal high water table is more than 6 feet.
Permeability is moderately rapid in the subsoil of the Barnstable soil and rapid or very rapid in the substratum. Available water capacity is moderate. Depth to the seasonal high water table is more than 6 feet.
Most areas are used as woodland. A few areas have been developed for homesites.
These soils are unsuitable as cropland because the surface stones and boulders interfere with the use of equipment. The Barnstable soil is suited to cultivated crops, however, if the stones and boulders are removed. The Plymouth soil is droughty during periods of low rainfall.
These soils are suited to native pasture. They are poorly suited to hay and improved pasture because the use of equipment is limited by the surface stones and boulders. The main management objective is the prevention of overgrazing, which reduces the hardiness and density of desirable plants. Proper stocking rates, timely grazing, and restricted use during wet periods help to maintain plant density and minimize surface compaction.
These soils are suited to woodland. The Plymouth soil is droughty. As a result, some seedling loss is expected. The use of equipment may be hampered because of the boulders. Thinning dense stands to standard stocking levels results in more vigorous tree growth. Removal or control of competing vegetation helps to obtain the best growth of newly established seedlings. The most common trees are pitch pine, white oak, scarlet oak, eastern white pine, and black oak.
Areas of these soils that have slopes of more than 8 percent are limited as sites for buildings. Land grading is generally needed. Buildings and lots should be designed so that they conform to the natural slope of the land. Erosion is a hazard during and after construction. Planting well suited grasses as soon as possible after the surface is disturbed minimizes the erosion hazard. The surface and subsurface stones and boulders may hamper site development.
These soils are limited as sites for septic tank absorption fields because of the slope and the rapid or very rapid permeability. The soils may not adequately filter the effluent. The poor filtering capacity may result in the pollution of ground water. The hazard of pollution increases with the density of housing. Installing the distribution lines on the contour or in areas that were graded during construction of the dwelling helps to overcome the slope. Precautionary measures may be necessary in some areas.
