Definition of subsoil in US English:



  • The soil lying immediately under the surface soil.

    • ‘Wetland creation attempts are often initiated by the removal of upland surface soil materials exposing mineral subsoil strata.’
    • ‘Soil and subsoil will be stocked for subsequent respreading.’
    • ‘Heavy clay subsoil or sandy soil with low fertility must be improved if roses are to be grown successfully in them.’
    • ‘These soils are moderately deep to deep, well-drained loam or silt loam surface soils with loam or silty clay loam subsoils, formed primarily in sandstone residuum.’
    • ‘When digging out the bed, discard any heavy, tight subsoil and save the topsoil.’


[with object]usually as noun subsoiling
  • Plow (land) so as to cut into the subsoil.

    • ‘Studies in the past showed that subsoiling clay soil in the spring does not improve cotton harvests.’