The global potential for mitigating nitrous oxide emissions from croplands

Summary

Agricultural activities contribute almost half of the total anthropogenic nitrous oxide (N₂O) emissions, but proper assessment of mitigation measures is hampered by large uncertainties during the quantification of cropland N₂O emissions and mitigation potentials. This review summarizes the up-to-date datasets and approaches to provide spatially explicit and crop-specific assessment of the global mitigation potentials. Here, we show that global cropland N₂O emissions have quadrupled to 1.2 Tg N₂O-N year⁻¹ over 1961–2020. The mitigation potential is 0.7 Tg N₂O-N without compromising the crop production, with 86% from optimizing nitrogen fertilization, three-quarters (78%) from maize (22%), vegetables, and fruits (16%), other crops (15%), wheat (13%), and rice (12%), and over 80% from South Asia, China, the European Union, other American countries, the United States, and Southeast Asia. More accurate estimation of cropland N₂O mitigation potentials requires extending the N₂O observation network, improving modeling capacity, quantifying the feasibility of mitigation measures, and seeking additional mitigation measures.