Subsoil synonyms

It rests on a subsoil of clay and marl.

As the drainage by cuniculi removed the moisture in the subsoil, so the drainage of the lakes by emissaria, outlet channels at a low level, prevented the permeable strata below the tufa from becoming impregnated with moisture which they would otherwise have derived from the lakes of the Alban Hills.

Here the prevailing soils are grey and sandy with a subsoil of loam, but they are less fertile than those of the Lime Sink or Cotton Belts.

The subsoil is either of clay, of limestone, or mixed sand and clay, gravel, or of a peculiar kind of pudding stone which exists in a hard and a soft variety.

Except on extremely heavy soils or on shallow soils with a subsoil which it is unwise to bring upon the surface, the modern tendency is in favour of the digging plough.