Carbon Footprint Reduction from Closing Rice Yield Gaps

Abstract

Rice production significantly contributes to greenhouse gas emissions (GHGE), especially methane (CH4) emissions at various cropping stages. A major source of methane emissions is the decomposition of fertilizers and organic residues in flooded fields during the irrigation cycle. CORIGAP technologies and practices are mainly associated with closing yield gaps by increasing productivity and profitability but have been co-designed to address climatic challenges and to minimize negative environmental impacts. Therefore, over the last decade, the CORIGAP interventions not only helped to reduce yield gaps substantially but also resulted in a significant reduction of the carbon footprint (CF) in rice production. This chapter starts with an in-depth synthesis of scientific-based evidence and knowledge on challenges and constraints to reducing rice CF in CORIGAP countries. The chapter introduces solutions that have been proven to reduce GHGE, in particular, Alternate Wetting and Drying (AWD), rice-straw management, mechanization, and postharvest management. The latter two approaches include laser land leveling, mechanized direct seeding and transplanting, and paddy grain drying will be described in more detail. In addition, life cycle assessments will outline the quantification of the carbon footprint in rice production, for these specific technologies. The chapter presents three country case studies (Thailand, Indonesia, and Vietnam) from data collected through CORIGAP activities to estimate GHGE reductions associated with implementation of best practices for lowland irrigated rice production. Lastly, this chapter provides the outcomes related to GHGE reduction and offers specific recommendations that can be easily implemented in other countries.