Manures and manufactured fertilisers cannot be applied in nitrate-vulnerable zones during defined closed periods. Proposals set out in the recent consultation for redefining the closed periods for organic manures have been developed using a targeted approach based on soil type, land use (arable or grassland) and rainfall. Under those proposals, the average length of the closed periods would be just over four months. There are no proposals to redefine closed periods for manufactured fertilisers.