JO_JohnstonJO-Johnston soils.
These nearly level, very poorly drained soils are on flood plains of the major streams. Areas are commonly
long and narrow. Most of the acreage is forested, and some small areas have been filled and used for
industrial and residential sites. The native vegetation consists of pond pine, tupelo-gum, ash, water oak,
cypress, red maple, sweetgum, American cyrilla, waxmyrtle, and gallberry.
Typically, the surface layer is 42 inches thick. It is black loam in the upper part and black sandy loam in the
lower part. The underlying layer, to a depth of about 64 inches, is light gray sand.
Included with these soils in mapping are small areas of Pamlico, Dorovan, and Murville soils. A few small
areas of soils that are less acid than these Johnston soils are also included.
The organic-matter content of the surface layer is high. Permeability is moderately rapid, available water
capacity is high, and shrink-swell potential is low. Reaction is very strongly acid or strongly acid
throughout, unless these soils are limed. The seasonal high water table is at or near the surface. These
soils are frequently flooded for long periods.
A seasonal high water table and flooding are the main limitations in the use and management of these
soils. These soils subside if drained and tilled. Capability subclasses VIIw, where undrained, and IVw,
where drained; woodland group Iw.