Sources of nitrous oxide emissions from agriculturally managed peatlands

Summary

Wang et al. (2024) used machine learning and global observational data to quantify nitrous oxide emissions from agriculturally managed peatlands and differentiate contributions from fertiliser application versus peat decomposition. The analysis reveals that croplands emit substantially higher N₂O than grasslands, with fertiliser accounting for a markedly different proportion of total emissions across land uses. The findings indicate that effective N₂O mitigation requires land-use and climate-specific strategies: fertiliser reduction and rewetting both show promise for tropical croplands, whilst peatland rewetting to arrest peat degradation should be prioritised for grasslands.

UK applicability

The United Kingdom has extensive agriculturally managed peatlands, particularly in England, Scotland and Northern Ireland, making this research directly relevant to UK climate targets and peatland restoration policy. The study's emphasis on differentiated mitigation strategies across land-use types could inform UK-specific guidance for peatland management, rewetting schemes, and fertiliser reduction programmes under agricultural transition support.

Key measures

Annual N₂O emissions (kt N year⁻¹); fertiliser-induced N₂O contribution; fertiliser-induced emission factors (1.5–3.2%); N₂O reduction potential from 20% fertiliser reduction; area of peatland requiring rewetting for equivalent emission reductions

Outcomes reported

The study quantified global N₂O emissions from agriculturally managed peatlands (401.0 kt N year⁻¹ from croplands; 64.0 kt N₂O-N year⁻¹ from grasslands) and apportioned emissions between fertiliser application and peat decomposition sources. The research compared mitigation potentials of fertiliser reduction versus peatland rewetting across land-use types and climatic zones.

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