Contribution of the postharvest period to soil N2O emissions from arable Mediterranean crops

Summary

This meta-analysis of 25 Mediterranean field studies demonstrates that postharvest soil N2O emissions contribute substantially to annual greenhouse gas budgets from herbaceous crops, averaging 26% of total cumulative emissions. When postharvest measurements are included, mean emission factors increase from 0.21% to 0.27%, with notably greater contributions from winter cereals and organic fertiliser applications. The findings indicate that omitting postharvest measurements systematically underestimates annual N2O emissions in certain Mediterranean cropping systems, with implications for accurate greenhouse gas accounting and targeted mitigation strategies.

UK applicability

While this study focuses on Mediterranean climates, the methodological approach and findings regarding postharvest N2O dynamics may be partially relevant to UK arable systems, particularly for winter cereal production. However, UK conditions differ substantially in temperature, soil moisture regimes and growing season length, so direct quantitative transfer of emission factors would be inappropriate without UK-specific validation.

Key measures

Cumulative N2O emissions (preharvest vs postharvest periods), N2O emission factors (%), maximum N2O flux peaks, relative contribution of postharvest period to total emissions

Outcomes reported

The study quantified the contribution of postharvest period N2O emissions to annual soil N2O budgets from herbaceous crops across 25 Mediterranean field studies. It calculated revised emission factors and identified crop types and management practices where postharvest measurements significantly alter annual greenhouse gas accounting.

Topic tags