Reduced Nitrous Oxide Emissions From Drained Temperate Agricultural Peatland After Coverage With Mineral Soil

Summary

This two-year field study on a Swiss drained fen grassland demonstrates that covering drained agricultural peatland with approximately 40 cm of mineral soil reduces nitrous oxide emissions by over 88%, from 20.5 to 2.3 kg N ha⁻¹ yr⁻¹ under intensive management with 230 kg N ha⁻¹ yr⁻¹ fertiliser input. The reduction was consistent across both fertilisation-induced peaks and baseline emissions, suggesting mineral soil coverage may be an effective management practice for simultaneously maintaining agricultural productivity whilst mitigating climate impact from managed peatlands. The findings are preliminary to understanding broader peatland management strategies that balance productivity and greenhouse gas mitigation.

UK applicability

The United Kingdom has extensive lowland agricultural peatlands, particularly in England and Scotland, that are similarly drained for grassland and arable production. These findings may have direct relevance to UK peatland management, though UK peatlands often have different soil characteristics, hydrology and climatic conditions than the Swiss Rhine Valley site studied, and the transferability of the 40 cm mineral soil covering approach would require local validation.

Key measures

Annual N₂O-N emissions (kg ha⁻¹ yr⁻¹); peak N₂O emissions following fertiliser application; background N₂O emissions; duration of post-fertilisation emission peaks

Outcomes reported

The study measured nitrous oxide (N₂O) emissions from an intensively managed grassland on drained peatland over two years, comparing an uncovered reference site with a site covered by approximately 40 cm of mineral soil. Results showed that mineral soil coverage reduced annual N₂O emissions from 20.5 ± 2.7 kg N ha⁻¹ yr⁻¹ to 2.3 ± 0.4 kg N ha⁻¹ yr⁻¹, with reductions observed in both fertilisation-induced peaks and background emissions.

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