Title: Dealing with nitrogen issues in agriculture; experiences from national to global scales
Abstract: After a brief introduction of my institute, the Netherlands Environmental Assessment Agency, I will present some characteristics of the Dutch agricultural sector (after the US the 2nd largest exporter in the world) as part of the European Union and the environmental consequences of the large and intensive Dutch agro sector. For this I will show some results of comparisons of the eco-efficiency of national agricultural sectors in Europe and between the EU and the US, as well as results of the 2017 evaluation of the Dutch Fertilize and Manure policy. Finally, I will show some results from the cost-benefit analysis of nitrogen use and losses, as these were produced in the (first) European Nitrogen Assessment (2007-2011) and in the ongoing UNEP project INMS (Towards a first Global Nitrogen Assessment; 2017-2021). Although quantifying societal costs of nitrogen pollution in agriculture is challenging and contested, comparing results with the obvious benefits of nitrogen use for crop and food production, point at important implications for optimal intensity (e.g. N fertilizer rate) and optimal spatial outlay of agriculture, at all scales.