Integrated Assessment of Nitrogen Losses from Agriculture in EU-27 using MITERRA-EUROPE

The high N inputs to agricultural systems in many regions in 27 member states of the European Union (EU-27) result in N leaching to groundwater and surface water and emissions of ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), and dinitrogen (N-2) to the atmosphere. Measures taken to decreasing these emissions often focus at one specific pollutant, but may have both antagonistic and synergistic effects on other N emissions. The model MITERRA-EUROPE was developed to assess the effects and interactions of policies and measures in agriculture on N losses and P balances at a regional level in EU-27. MITERRA-EUROPE is partly based on the existing models CAPRI and GAINS, supplemented with a N leaching module and a module with sets of measures. Calculations for the year 2000 show that denitrification is the largest N loss pathway in European agriculture (on average 44 kg N ha(-1) agricultural land), followed by NH3 Volatilization (17 kg N ha(-1)), N leaching (16 kg N ha(-1)) and emissions of N2O (2 kg N ha(-1)) and NOx (2 kg N ha(-1)). However, losses between regions in the EU-27 vary strongly. Some of the measures implemented to abate NH3 emission may increase N2O emissions mid N leaching. Balanced N fertilization has the potential of creating synergistic effects by simultaneously decreasing N leaching and NH3 and N2O emissions. MITERRA-EUROPE is the first model that quantitatively assesses the possible synergistic and antagonistic effects of N emission abatement measures in a uniform way in EU-27.