Effect of rice husk and bamboo biochar on CH4 and N2O emission from alluvial paddy soil under laboratory conditions

Abstract

Using biochar is a potential solution to reduce greenhouse gas emissions. This study was conducted to evaluate and compare CH₄ and N₂O emissions from paddy soil supplemented with rice husk biochar and bamboo biochar under two conditions: continuous flooding and alternating drying and wetting with a moisture of 90%. Each experiment was set up with seven treatments consisting of rice husk biochar and bamboo biochar at a portion of 0.1, 0.2, 0.5%, and a control (without biochar). In continuous flooding soil, CH₄ emission was the primary process, and in 90% moisture paddy soil, N₂O was the main emission. When rice husk biochar was amended at the rate of 0.2 and 0.5%, the total CH₄ emissions were reduced by 27.66–45.19% compared with the control treatment (p < 0.05). Using rice husk biochar reduced total N₂O emissions by 5.9–9.6 times while applying bamboo biochar reduced 4.1–5.9 times compared with the control treatment (p < 0.05). The supplement of rice husk biochar at 0.5% provided the highest efficiency of greenhouse gas emission was reduced at 8.9 times lower than the control and 50.3% lower than bamboo biochar at the same rate.