Loosening of the soil before planting a new vineyard by deep ploughing at a depth of usually at least 30 to 80 centimetres, in rare cases up to 120 centimetres depending on the soil type (the Dutch-French infiltration ditch means deep gully or drainage ditch). The vineyard soils, some of which have been used for a thousand years, used to be rigged by hand every 30 to 80 years. Today this is done by machine every 20 to 40 years, unless it is completely dispensed with. This results in a loosening of the soil, the removal of compacted layers and the enrichment of the subsoil with missing nutrients, which is especially important when planting the young vines. Root residues must be completely removed in order to prevent later rotting and thus the spread of bacteria. This work is carried out in late autumn until the onset of winter. The resulting soil is called Rigosol. See also fertilisation and uprooting, and a complete list of all activities under vineyard care.