Global benefits of non‐continuous flooding to reduce greenhouse gases and irrigation water use without rice yield penalty. (23rd February 2022)

• Record Type: Journal Article
• Authors: Bo, Yan; Jägermeyr, Jonas; Yin, Zun; Jiang, Yu; Xu, Junzeng; Liang, Hao; Zhou, Feng
• Is Part Of: Global change biology. Volume 28:Number 11(2022)
• Page Start: 3636
• Page End: 3650
• Publication Date: 2022-02-23
• Subjects: climate change mitigation -- food security -- methane emissions -- nitrous oxide emissions -- rice production -- Water conservation; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.16132
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Non‐continuous flooding is an effective practice for reducing greenhouse gas (GHG) emissions and irrigation water use (IRR) in rice fields. However, advancing global implementation is hampered by the lack of comprehensive understanding of GHGs and IRR reduction benefits without compromising rice yield. Here, we present the largest observational data set for such effects as of yet. By using Random Forest regression models based on 636 field trials at 105 globally georeferenced sites, we identified the key drivers of effects of non‐continuous flooding practices and mapped maximum GHGs or IRR reduction benefits under optimal non‐continuous flooding strategies. The results show that variation in effects of non‐continuous flooding practices are primarily explained by the UnFlooded days Ratio (UFR, that is the ratio of the number of days without standing water in the field to total days of the growing period). Non‐continuous flooding practices could be feasible to be adopted in 76% of global rice harvested areas. This would reduce the global warming potential (GWP) of CH4 and N2 O combined from rice production by 47% or the total GWP by 7% and alleviate IRR by 25%, while maintaining yield levels. The identified UFR targets far exceed currently observed levels particularly in South and Southeast Asia, suggesting large opportunities for climate mitigation and water use conservation, associated with the rigorous implementation of non‐continuous flooding practices in global rice cultivation. Abstract : Here, we analyze global benefits of non‐continuous flooding to reduce greenhouse gases and irrigation water use. Non‐continuous flooding could be adopted in 76% of global rice harvested areas. This could reduce the global warming potential of methane and nitrous oxide from rice production combined by 47% and alleviate irrigation water use by 25%, while maintaining yield levels. This study highlights the value of rigorous implementation of non‐continuous flooding for climate mitigation and water use conservation in global rice cultivation.