Agri-environment schemes as landscape experiments

Agri-environment schemes are payments to farmers to address environmental problems. More than 300 different policy measures are implemented in the member countries of the Organisation for Economic Co-operation and Development (OECD), mostly addressing water, biodiversity and landscape protection. About 20% of the farmland of the European Union are under some form of agri-environment scheme. These schemes can be regarded as landscape experiments because semi-natural biotopes are being deliberately introduced and matter (nutrients, pesticides) and energy flows are manipulated. Their evaluation, however, is methodologically difficult and the few existing studies are controversial. More research on agri-environment schemes is needed to assess and improve their effectiveness.