Optimizing water management practices for enhancing rice production and mitigating greenhouse gas emissions in Asia: The food-water-climate nexus approach

Abstract:

Rice fields, supporting over half of the global population, consumed around 30% of the freshwater used for global crop growth and identified as one of the major methane (CH₄) sources. Asia, in where 90% of rice is consumed, took over 90% of the total CH₄ emission from the global rice field. With the increasing water scarcity and rapidly growth population, it is urgent to address how to simultaneously maintain or even increase food production, reduce water consumption, and benefit climate. In this study, we used a process-based model (Dynamic Land Ecosystem Model), which has the capability to simultaneously simulate the carbon, water, and nitrogen fluxes and storages within the terrestrial ecosystem, and also the exchanges of greenhouse gases between terrestrial ecosystems and the atmosphere, to quantify the magnitude, spatial and temporal variation of rice production and CH₄ emissions under different water management practices. Simulated results have been evaluated against field observations, inventory-based and atmospheric inversion estimates. By implementing a set of experimental simulations, the results could provide insights for reasonable implementation of optimum water management practices, which is also crucial for policy maker to make trade-off decisions to increase yield and reduce GHG emissions through effective mitigation strategies.