Straw-based bioenergy for carbon-neutral agriculture with sustained soil carbon growth

Crop straw management presents a critical trade-off in climate mitigation: balancing straw return for carbon sequestration against conversion into carbon-neutral bioenergy. The potential for agricultural systems to synergistically achieve both ambitious soil carbon growth and substantial greenhouse gas (GHG) reductions remains not fully understood. The integration of the Rothamsted Carbon Model (RothC) and a Bioenergy-Emission-Economic Model (BEE) enabled a systematic evaluation of the carbon balance effects of straw management in China (2021–2100) under varying soil organic carbon (SOC) targets. The results demonstrate that even under an ambitious 4 per mille SOC target, allocating a substantial share of straw resources to bioenergy production still yields robust climate mitigation benefits for the agricultural system. Under this target, the agricultural system exhibits significant climate mitigation potential, capable of fully offsetting China’s total agricultural GHG emissions. Spatial analysis further identifies East and Central China as priority regions for implementing this synergistic pathway, due to their abundant straw resources and relatively high carbon sequestration efficiency. These findings indicate that enhancing soil carbon and deploying straw-based bioenergy are not mutually exclusive, but can act as synergistic pillars for achieving agricultural carbon neutrality through spatially optimized allocation. The agricultural sector has the potential to evolve into a reliable system for climate mitigation that supports carbon neutrality while safeguarding soil health.