The following is a map unit description from the "Soil Survey of Norfolk and Suffolk Counties, Massachusetts (Peragallo, 1989)"

NpC-Newport silt loam, 8 to 15 percent slopes. This is a deep, strongly sloping, well drained soil on side slopes of upland hills in the Boston Basin and along the Plymouth County line. Areas are oval and range from 6 to 30 acres.

Typically, the surface layer is dark brown silt loam about 7 inches thick. The subsoil is light olive brown silt loam about 17 inches thick. The substratum is firm, light yellowish brown silt loam to a depth of 60 inches or more. In many areas the coarse fragments in the soil are commonly 50 to 75 percent, by volume, flat, dark gray shale and slate and are 1 to 15 inches long.

Included with this soil in mapping are small areas of Paxton soils in positions on the landscape similar to those of the Newport soil. Also included are small areas of Pittstown soils in depressions. Also included are small areas of Udorthents, loamy, where Newport soils have been cut away or covered with more than 20 inches of loamy fill material. Also included are a few small areas of Urban land where the soil is covered with impervious surfaces, such as pavement or buildings. Included soils and areas of Urban land make up about 15 percent of this map unit.

Soil properties:

Permeability: Moderate in the surface layer and the subsoil and slow in the substratum.

Available water capacity: Moderate.

Soil reaction: Very strongly acid to moderately acid throughout.

Depth to bedrock: More than 60 inches.

Depth to the seasonal high water table: 1.5 to 2.5 feet.

Hydrologic group: C.

Most areas of this soil are used for parks and playgrounds.

This soil is well suited to lawns, landscaping, cultivated crops, hay, and pasture and to use as orchards. Erosion is a hazard and is the main management concern. Contour tillage, stripcropping, diversions, cover crops, and grasses and legumes in the cropping system help to reduce runoff and to control erosion.

Potential productivity for northern red oak on this soil is moderately high. The soil is easily managed for woodland use. The high productivity of this soil justifies intensive management for either hardwoods or conifers. Plant competition at regeneration is moderate if conifers are grown. Thinning crowded stands to accepted, standard stocking levels allows more vigorous growth. Shelterwood cutting, seed-tree cutting, and clearcutting help to establish natural regeneration or to provide suitable planting sites. Removing or controlling competing vegetation allows best growth of newly established seedlings. Pruning helps to improve the quality of white pine.

Tile drains around foundations help to lower the seasonal high water table. Land shaping is needed in some areas. Designing lots to drain surface water away from buildings also helps protect the interior from damage by the seasonal high water table. Slope, the seasonal high water table, and potential frost action are the main limitations for road construction. Constructing roads on the contour, if possible, and planting roadbanks to well adapted grasses help to control erosion. Constructing roads on well compacted, coarse textured base material and providing adequate side ditches and culverts help to prevent the damage to the pavement by the seasonal high water table and potential frost action.

If the soil is used as sites for septic tank absorption fields, slow permeability of the soil restricts it from readily absorbing the effluent. Installing a drain field that is larger than average helps to overcome this limitation. Where a vegetative cover cannot be maintained during construction, sediment and erosion control structures help to control erosion.

  • This soil is in capability subclass IIIe.
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