Soil Survey of
Nantucket County Massachusetts
The following map unit description is from the published "Soil
Survey of Nantucket County, Massachusetts"
Kp-Klej and Pompton soils. This unit consists of nearly level soils in shallow depressions and drainageways, on broad outwash plains, and in low lying areas near streams and ponds. The areas are irregularly shaped and range from 3 to 50 acres. These areas consist of moderately well drained Klej soils or somewhat poorly drained Pompton soils or both. The soils were mapped together because there are no major differences in their use and management. About 45 percent of the total acreage of this unit is Klej soils, 40 percent is Pompton soils, and 15 percent is other soils.
Typically, the Klej soils have a surface layer of black loamy sand about 3 inches thick. The subsoil is 38 inches thick. The upper 19 inches is friable, dark brown and reddish brown loamy sand; the middle 4 inches is strong brown, mottled, very friable sand; and the lower 15 inches is red, mottled, loose sand. The substratum extends to a depth of 60 inches. It is light olive brown, mottled sand in the upper part; light olive brown, mottled sandy loam in the middle part; and light olive brown, mottled sandy clay loam in the lower part.
Typically, the Pompton soils have a surface layer of dark brown fine sandy loam about 5 inches thick. The subsurface layer is dark gray sandy loam about 5 inches thick. The subsoil is about 20 inches thick. It is dark yellowish brown and light olive brown, friable sandy loam that is mottled in the lower part. The substratum is light olive brown gravelly sand to a depth of 60 inches or more.
Included with these soils in mapping are small areas of Berryland Variant, Evesboro, Plymouth, and Riverhead soils. Also included in areas of Klej soils are soils with slopes of more than 3 percent, areas ot soils where the upper part of the subsoil is sandy loam, and areas of soils with silt and clay in the substratum. In a few places the subsoil of the Pompton soils is loamy sand. Included soils make up about 15 percent of this unit.
The permeability of the Klej soils is rapid or very rapid. Available water capacity is low. The Klej soils have a seasonal high water table at a depth of 1.5 to 2 feet in winter and spring. The seasonal high water table restricts root growth in spring.
The permeability of the Pompton soils is moderate or moderately rapid in the surface layer and subsoil and rapid or very rapid in the substratum. Available water capacity is moderate The Pompton soils have a seasonal high water table at a depth of 1 to 2 feet in winter and spring. The seasonal high water table restricts root growth in spring.
Many areas of these soils are covered with woody vegetation. Some are covered with grass, The soils in this unit are suitable for openland wildlife habitat and woodland wildlife habitat but are poorly suited to most other nonfarm uses.
The soils in this unit are suited to crops, hay, and pasture but are limited by wetness. Surface drainage, diversions, tile drainage, or a combination of these practices helps remove water from the soils. Insufficient rainfall in summer causes drought, and irrigation is needed. The main management concern for pasture is the prevention of overgrazing, which causes surface compaction and reduces the hardiness and density of plants.
The seasonal high water table in these soils is the main limitation for most nonfarm uses, including building sites, roads and streets, and septic tank absorption fields. Areas used for building sites or roads and streets need to be drained. These soils have a moderate or high frost action potential; replacing the upper layer of the soil with a more suitable base material helps to prevent damage caused by frost action.
Capability subclass IIIw.