Assessment of Greenhouse Gas Emissions from Post-harvest Rice-straw Burning in Triple- and Double-crop Systems in the Upper Vietnamese Mekong Delta

Abstract

Rice farming is a major contributor to greenhouse gas (GHG) emissions in the agricultural sector, especially in the Vietnamese Mekong Delta (VMD). We surveyed 202 rice-farming households (382.9 ha) in Dong Thap Province (Upper VMD) and estimated CO₂, CH₄, and N₂O emissions from post-harvest rice-straw burning using IPCC (2006) Tier-2 methods. In 2024, straw was burned on 333.9 ha (87% of the surveyed area) and removed off-field on 49.0 ha. Total emissions were 415.14 t CO₂e, dominated by CH₄. Emission intensity was higher in triple-crop systems (1.26–1.55 t CO₂e·ha^-1·yr^-1) than in the double-crop system (1.03 t CO₂e·ha^-1·yr^-1). Reducing in-field burning through straw utilization (incorporation/composting, mushroom cultivation, livestock feed) and, where feasible, moderating cropping intensity can lower emissions while maintaining soil fertility. The study provides important data to support policy development and encourages farmers to adopt low-emission alternatives for post-harvest residue management.