Comparative Study of Methane Emission and Structural Development of Rice Plants from SRI and non-SRI Methods in a Lysimeter Experiment

抄録

Mitigating greenhouse gas (GHG) emission is a challenging issue in context of coping with the ongoing climate change. Rice farming is considered as the major emitter of CH₄ along with gaseous N₂O. There are several methods of irrigation management that reduces the amount of CH₄ and N₂O gases produced, such as intermittent irrigation and mid-season drainage. SRI (System of Rice Intensification) is one of the new methods known to increase the yield while mitigating GHGs by applying one of key elements intermittent irrigation, and is a method which is now disseminating in many tropical countries. This study was conducted to measure the effectiveness of SRI method by measuring rice plant development, yield component, and methane emission using a lysimeter facility. The transplanted nursery was koshihikari, a Japanese rice variety. The study compared between two plots with different water treatments. The results showed that a plant growth characteristics were better in a Continuous plot than in a Intermittent plot, while grain yield was not significantly different. Methane gas was almost 50% less in the Intermittent plot than in the Continuous plot. Total global warming potential from methane emission for Intermittent plot and Continuous plot were 50.41 g CO₂/m² and 100.53 g CO₂/m², respectively. The results suggest that SRI methodology could be an effective method for mitigating methane emission without reducing the grain yield.