Effect of Biochar Application on Rice Yield and Greenhouse Gas Emission under Different Nutrient Conditions from Paddy Soil

This study was conducted to investigate the effect of biochar application on rice yield and greenhouse gases in nutrient-poor soil (NPS) and nutrient-rich soil (NRS). The treatment conditions for NPS and NRS plots were control (C), Ffertilizer (F), and sesame straw biochar + F (BC) treatments. The rice yields were higher in the order of BC(421.8 g m−2)>F>C for the NPS plot and BC(802.4 g m−2)>C>F for the NRS plot. CH4 flux with the NPS plot was similar to that of the NRS plot, whereas N2O flux in the NRS plot was greater than in the NPS plot in all tested treatments. The global warming potential in biochar application treatments was lower, with the global CH4+N2O fluxes decreased by 25.0–36.8% for the NPS plot and 16.7–39.4% for the NRS plot, compared with the corresponding other treatments. These results suggest that biochar application in NPS and NRS will enhance rice productivity and reduce CH4 and N2O fluxes.