Integrated biochar solutions can achieve carbon-neutral staple crop production

Agricultural food production is a main driver of global greenhouse gas emissions, with unclear pathways towards carbon neutrality. Here, through a comprehensive life-cycle assessment using data from China, we show that an integrated biomass pyrolysis and electricity generation system coupled with commonly applied methane and nitrogen mitigation measures can help reduce staple crops' life-cycle greenhouse gas emissions from the current 666.5 to -37.9 Tg CO2-equivalent yr(-1). Emission reductions would be achieved primarily through carbon sequestration from biochar application to the soil, and fossil fuel displacement by bio-energy produced from pyrolysis. We estimate that this integrated system can increase crop yield by 8.3%, decrease reactive nitrogen losses by 25.5%, lower air pollutant emissions by 125-2,483 Gg yr(-1) and enhance net environmental and economic benefits by 36.2%. These results indicate that integrated biochar solutions could contribute to China's 2060 carbon neutrality objective while enhancing food security and environmental sustainability. Chinese agricultural production is key to achieve the country's 2060 carbon neutrality target. Combining meta-analysis and life-cycle assessment, this study estimates the climate change mitigation potential of straw, biochar, and an integrated biomass pyrolysis and electricity generation system.

Automated summary

This study, using data from China, shows that an integrated biomass pyrolysis and electricity generation system combined with methane and nitrogen mitigation measures can significantly reduce greenhouse gas emissions from staple crops. The reductions are mainly achieved through carbon sequestration from biochar application and displacement of fossil fuels by bio-energy. The integrated system also has various environmental and economic benefits, such as increased crop yield and decreased air pollutant emissions.