Intermittent irrigation as a solution for reduced emissions and increased yields in ratoon rice systems

Background and aims Sustainable rice production is crucial for addressing food security and mitigating climate change. Optimizing irrigation techniques that strike a balance between rice yields and carbon sequestration has gained significant attention. Intermittent irrigation has been considered a compromise between these two factors. However, uncertainties persist regarding the impact of intermittent irrigation on ratoon rice cultivation. Methods To address this, we conducted field experiments to investigate the influence of intermittent irrigation on rice yield and CO 2 /CH 4 emissions in ratoon rice systems at Qianshanhong Farm, located in Yiyang, Hunan Province, China. We utilized a portable greenhouse gas analyzer from Los Gatos Research (LGR) alongside the closed chamber method to measure gas fluxes accurately. The experiments were conducted on Huanghuazhan rice cultivar, with each plot encompassing 45 m 2 . The experiments included intermittent irrigation treatment and conventional flooded irrigation treatment as a control. Results The study found that the ecosystem respiration ( ER ), heterotrophic soil respiration ( HR ), Gross primary productivity ( GPP ), Plant autotrophic respiration ( PR ), and total accumulated CH 4 emissions from the ecosystem ( E_CH_4 ) of ratoon rice decreased owing to intermittent irrigation. Intermittent irrigation increased rice yield and biomass by 6.04