Aspects of Applied Biology 100, 2010 Agri-environment schemes - what have they achieved and where do we go from here? 311 Benchmarking biodiversity performances of farmers By G R DE SNOO 1,2 , A M LOKHORST 3 , J VAN DIJK 1 , H STAATS 3 and C J M MUSTERS 1 1 Leiden University, Institute of Environmental Sciences, P.O. Box 9518, 2300 RA Leiden, NL 2 Wageningen University, Centre for Ecosystem Studies, P.O. Box 47, 6700 AA Wageningen, NL 3 Leiden University, Institute for Psychological Research, P.O. Box 9555, 2300 RB Leiden, NL Summary Farmers are the key players when it comes to the enhancement of farmland biodiversity. In this study, a benchmark system that focuses on improving farmers’ nature conservation was developed and tested among Dutch arable farmers in different social settings. The results show that especially tailored information combined with public commitment making resulted in a stronger desire to engage in conservation, an increase in surface area of non-subsidized natural habitat, and an increase in time farmers spent on conservation. The feedback given to the farmers especially affected the non-subsidized conservation. Benchmarking instruments using targeted information might be challenging tools for farmers. Key words: Farmers’ behaviour, benchmarking, feedback, biodiversity Introduction Farming is by nature an activity which has a very large impact on biodiversity and landscape. Within Europe, especially due to the Common Agricultural Policy (CAP), agricultural production has been increased strongly. However, the drawbacks of the increase of yields on biodiversity and landscape quality are well known (Stoate et al., 2009; Geiger et al., 2010). To counteract the loss of biodiversity and landscape quality in the countryside, Agri-Environmental Schemes (AES) have been developed within the modern CAP. Although the AES have been implemented on a large scale, their effectiveness is only moderate and has been a topic of discussion among scientists and the general public. In some countries the debate is starting whether enhancing of biodiversity on farmland is really possible and people are arguing that we should spend our money on nature reserves only. Currently, the main approach for enhancing biodiversity by farmers is top down steering by governments. Over the years, with the help of researchers, governments have developed management regulations. Farmers can join the AES on a voluntary basis. However, even though in most cases farmers carry out these management regulations diligently, many species in the agricultural landscape remain under pressure. These poor results lead to disappointed farmers, conservationists and policymakers. The need to improve the effectiveness of the conservation efforts in the countryside is therefore clear. How can nature conservation on farmland be improved? On the one hand we can identify bottlenecks in the ield of the natural sciences underpinning conservation measures, especially regarding the landscape-ecological set up of the AES. On the other hand we should reconsider