The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields

Abstract EN

A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation.

Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harvesting than no residue treatment.

During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha−1 season−1 to 1654 kg C ha−1 season−1 than no residue treatment.

Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions.

Residue mulching treatments significantly increased GWP by 9–30% but significantly decreased net GWP by 33–71% and GHGI by 35–72% relative to no residue treatment.

These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China.