Sources of nitrous oxide emissions from agriculturally managed peatlands

Summary

This global analysis, employing machine learning on N₂O observational data, quantifies the relative contributions of fertiliser nitrogen and peat decomposition to nitrous oxide emissions from managed peatlands. The study demonstrates that mitigation strategies should be tailored by land-use type and climate: for croplands, both fertiliser reduction and rewetting are viable, whilst for grasslands, rewetting to halt peat degradation is preferentially effective. The findings indicate substantial variation in fertiliser-induced emission factors and highlight the limited mitigation potential of fertiliser reduction alone for grassland systems.

UK applicability

The United Kingdom has significant areas of managed lowland peatlands, particularly in England and Scotland used for both arable and grassland agriculture. These findings are directly applicable to UK peatland management policy and practice, informing the development of site-specific mitigation strategies; however, UK-specific climate and soil conditions may require localised calibration of emission factors and rewetting feasibility assessments.

Key measures

Annual N₂O emissions (kt N year⁻¹); fertiliser-induced N₂O emission factor (%); N₂O emission reductions from 20% fertiliser reduction; area of peatland requiring rewetting to achieve equivalent emission reductions

Outcomes reported

The study used machine learning and global N₂O observational data to quantify nitrous oxide emissions from agriculturally managed peatlands, distinguishing contributions from fertiliser application versus nitrogen release from peat decomposition. It evaluated the comparative mitigation potential of fertiliser reduction and peatland rewetting across croplands and grasslands in different climatic zones.

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