The following is a map unit description from the "Soil Survey of Barnstable County, Massachusetts (Fletcher, 1993)"
HkC-Hinckley gravelly sandy loam, 8 to 15 percent slopes. This very deep, strongly sloping, excessively drained soil is on small hills and ridges on outwash plains and in areas of ice-contact deposits. It makes up about 0.2 percent (545 acres) of the survey area. It is mapped mainly in the Enfield-MerrimacCarver general soil map unit. Areas are irregular in shape and range from 5 to 1 00 acres in size.
Typically, the surface is covered with an organic layer. This layer is about 2 inches of loose, undecomposed pine needles, leaves, and twigs and 1 inch of partly decomposed and well decomposed organic material. The surface layer is very friable gravelly sandy loam about 2 inches thick. The upper 1 inch is black, and the lower 1 inch is dark grayish brown. The subsoil is about 15 inches thick. The upper 1 inch is dark reddish brown, friable gravelly sandy loam; the next 7 inches is yellowish brown, friable gravelly sandy loam; and the lower 7 inches is yellowish brown, friable gravelly loamy coarse sand. The substratum extends to a depth of 65 inches or more. It is brownish yellow, loose very gravelly coarse sand in the upper 37 inches and light yellowish brown, loose gravelly coarse sand in the lower part.
Included with this soil in mapping are small areas of Carver, Merrimac, and Plymouth soils. Also included are areas where slopes are less than 8 percent or more than 15 percent. Included soils make up about 30 percent of this unit.
Permeability is rapid in the subsoil of the Hinckley soil and very rapid in the substratum. Available water capacity is low. Depth to the seasonal high water table is more than 6 feet.
Most areas are used as woodland. Some areas have been developed for homesites.
This soil is poorly suited to cultivated crops. The low available water capacity and the hazard of erosion are management concerns. Irrigation is needed for most cultivated crops. Mixing plant residue and manure into the surface layer increases the available water capacity. Farming on the contour or across the slope, terracing, stripcropping, including grasses and legumes in the crop rotation, growing cover crops, and applying a system of conservation tillage help to control runoff and erosion.
This soil is poorly suited to hay and pasture. 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.
Because of the droughtiness, this soil is poorly suited to woodland. Thinning dense stands to standard stocking levels results in more vigorous tree growth. Diseased, deformed, and otherwise undesirable trees should be removed when the stands are thinned. The most common trees are eastern pitch pine, white oak, scarlet oak, black oak, and eastern white pine. Generally, these trees are of poor quality.
The slope is the main limitation if this soil is used as a site for buildings. Land shaping 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 droughtiness is a limitation affecting lawns and shallowrooted trees and shrubs. Adding a layer of topsoil and frequently watering during dry periods help to overcome this limitation.
This soil is poorly suited to septic tank absorption fields because of the slope and the rapid or very rapid permeability. The soil 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.
