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

TLDR

High nitrogen inputs in EU‑27 agriculture lead to leaching into water bodies and emissions of NH₃, N₂O, NO, and N₂, and mitigation measures targeting a single pollutant can produce antagonistic or synergistic effects on other nitrogen emissions. The MITERRA‑EUROPE model was developed to assess how agricultural policies and measures influence nitrogen losses and phosphorus balances at a regional level across the EU‑27. MITERRA‑EUROPE builds on the CAPRI and GAINS models, adding a nitrogen leaching module and a module that incorporates various mitigation measures. In 2000, denitrification was the largest nitrogen loss pathway (≈44 kg N ha⁻¹), followed by NH₃ volatilization (≈17 kg N ha⁻¹), N leaching (≈16 kg N ha⁻¹), and N₂O and NOₓ (≈2 kg N ha⁻¹ each), with substantial regional variation; some NH₃‑abatement measures increased N₂O and leaching, whereas balanced fertilization could simultaneously reduce multiple emissions, and MITERRA‑EUROPE uniquely quantifies these synergistic and antagonistic effects across the EU‑27.

Abstract

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 (NH 3 ), nitrous oxide (N 2 O), 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 NH 3 volatilization (17 kg N ha −1 ), N leaching (16 kg N ha −1 ) and emissions of N 2 O (2 kg N ha −1 ) and NO X (2 kg N ha −1 ). However, losses between regions in the EU‐27 vary strongly. Some of the measures implemented to abate NH 3 emission may increase N 2 O emissions and N leaching. Balanced N fertilization has the potential of creating synergistic effects by simultaneously decreasing N leaching and NH 3 and N 2 O 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.