Serra, JoãoMarques-dos-Santos, CláudiaMarinheiro, JoanaAguilera, EduardoLassaletta, LuisSanz-Cobeña, AlbertoGarnier, JosetteBillen, GillesVries, Wim deDalgaard, TommyHutchings, NicholasCameira, Maria do Rosário2024-07-092024-07-092023-09Serra, João, et al. “Nitrogen Inputs by Irrigation Is a Missing Link in the Agricultural Nitrogen Cycle and Related Policies in Europe.” Science of The Total Environment, vol. 889, Sept. 2023, p. 164249http://hdl.handle.net/10400.5/31256Irrigation, one of the 28 agri-environmental indicators defined in the European Common Agricultural Policy, is often neglected in agricultural nitrogen (N) budgets, while it can be a considerable source of N in irrigated agriculture. The annual N input from irrigation water sources (NIrrig) to cropping systems was quantified for Europe for 2000–2010 at a resolution of 10 × 10 km, accounting for crop-specific gross irrigation requirements (GIR) and surface- and ground- water nitrate concentration. GIR were computed for 20 crops, while spatially explicit nitrate concentration in ground- water was derived using a random forest model. We show that although GIR were relatively stable (46–60 km3 yr-1), the Nirrig in Europe increased over the 10-year period (184 to 259 Gg N yr-1), approximately 68 % of which occurred in the Mediterranean region. The main hotspots appeared in areas with both high irrigation requirements and high groundwater nitrate concentration, reaching up to averaged values of 150 kg N ha-1 yr1. These were mainly located in Mediterranean Europe (Greece, Portugal and Spain) and to a lesser extent in Northern Europe (The Netherlands, Sweden and Germany). By not including NIrrig, environmental and agricultural policies are underestimating the real extent of N pollution hotspots in European irrigated systems.engirrigation waterNitrate pollutionnutrient managementwater managementagrienvironmental indicatorwater balancejournal article10.1016/j.scitotenv.2023.164249