Deli Chen, University of Melbourne, Parkville, VIC, Australia, Baojing Gu, Zhejiang University, Hangzhou, China, Hans Van Grinsven, Netherlands Environmental Assessment Agency, Bilthoven, Netherlands, Shu Kee Lam, University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, VIC, Australia, Oene Oenema, Wageningen University, Department of Soil Quality, Wageningen, Netherlands and Mark A Sutton, NERC Natural Environment Research Council, Swindon, United Kingdom