Biodegradable film mulching reduces the climate cost of saving water without yield penalty in dryland rice production

Global resource shortage and climate change are the grandest challenges facing traditional flooded rice cultivation. In this study, different rice production patterns were examined to quantify the effects on crop production, greenhouse gas (GHG) emissions, and synchronization index of water conservation and GHG mitigation. The results indicated that rice direct dryland seeding with biodegradable mulching showed the best performance in maintaining yield (7,802 kg ha-1), saving irrigation water (67%), increasing net profit (619 CNY ha-1), reducing CH4 emissions (73%), global warming potential (69%) and GHG intensity (69%), although it increased N2O emissions (59%), compared with continuous flooding. Rice direct dryland seeding without mulching showed similar water savings and GHG mitigation with mulching, but it caused yield and net profit reductions by 20% and 40%, and synchronization index increment by 127%. These findings can guide the implementation of dryland rice production in priority areas, contributing to high-efficiency, eco-friendly agricultural cultivation.