Zeolite Increases Grain Yield While Mitigating Greenhouse Gas Emissions Under Different Irrigation Regimes

Clinoptilolite zeolite (Z) has been widely used for reducing nutrient loss and improving crop productivity. However, the impacts of zeolite on CH4 and N2O emissions in rice fields under various irrigation regimes are still unclear. Therefore, a three-year field experiment using a split-plot design investigated the impacts of zeolite addition and irrigation regimes on greenhouse gas emissions and grain yield in a paddy field. The field experiment included two irrigation regimes (CF: continuous flooding irrigation; AWD: alternate wetting and drying irrigation) as the main plots, and three zeolite additions (0, 5 and 10 t ha−1 ) as the subplots. The results indicated that AWD regime significantly decreased seasonal cumulative CH4 emissions by 71% compared with CF regime in 2017. However, AWD regime significantly increased seasonal cumulative N2O emissions by 32% and 353% compared with CF regime in 2017 and 2018, respectively. Compared with non-zeolite treatment, 5 t ha−1 zeolite significantly mitigated cumulative CH4 emissions by an average of 36%. Grain yield under AWD regime was enhanced by an average of 6.3% relative to CF regime. Zeolite addition at 5 and 10 t ha−1 enhanced rice yield by an average of 11.4% and 21.2%, respectively. Accordingly, the yield-scaled global warming potential under AWD regime was decreased by 59% related to CF regime in 2017. Thus, zeolite addition at 5 t ha−1 coupled with AWD regime could be an attractive strategy to meet the “win-win” goal of enhancing grain yield while lowering greenhouse gas emissions in rice fields