In addition to sessions on the latest results of basic research in this research area, another highlight of the conference is a public symposium on the environmental problem of nitrogen. The keynote speakers are two renowned experts, Eric Davidson from the University of Maryland (USA) and Jan-Willem Erisman from the Louis Bolk Institute (Netherlands). They talk about the context of over-fertilization, conventional agriculture and meat consumption and present perspectives for the improvement of these problems. icon5.univie.ac.at