The fate of anthropogenic nitrogen is at the core of our environmental predicament. Human activities have more than doubled the annual input of reactive nitrogen to the biosphere compared to prehistoric levels, causing escalating emissions of nitrous oxide (N2O) which contributes to global warming and depletion of stratospheric ozone. Ultimately, anthropogenic nitrogen will return to the atmosphere, either as N2, N2O or NO, which are the gaseous products of microbial red/ox-transformations of mineral nitrogen. The N2/N2O/NO product ratio of these transformations is controlled by the ecology and regulatory biology of the organisms involved, modulated by environmental factors. We need better understanding and quantification of these processes to improve our chances to reduce N2O emissions from managed ecosystems (agriculture and waste treatment systems). Such progress requires interdisciplinary scientific approaches in collaboration with the fertilizer and waste-industries.NORA comprises the strongest research groups in Europe regarding the biochemistry, biotechnology, physiology and ecology of N-transforming microbes in soils and wastewater systems, the R&D of leading fertilizer-, waste treatment- and robot- industry. Major goals are to• improve our understanding and predictive ability regarding the ecology and regulatory biology of microbes involved in oxidation and reduction of mineral N species affecting atmospheric N2O.• produce a new generation of nitrogen researchers, within both academic and private sectors, with inter- and cross-disciplinary skills and understanding and appreciation of both fundament science and its direct application to environmental, industrial and societal issues.• exploit the power of fundamental scientific understanding, developed through interdisciplinary research and close interactions between academia, industry and policy makers, to generate specific recommendations, strategies and solutions to reduce nitrous oxide emissions.