04. Effect of biogas digested liquid and melaleuca biochar amendment on CH4 and N2O emission from paddy soil

Abstract

Biogas production from livestock waste and the use of biogas effluent as fertilizer for crops will be a promising technology to deal with these water pollution problems. However, biogas effluent produced in anaerobic digesters contains about 60 % methane. Therefore, it could lead to the risk of increasing greenhouse gas emissions. A pot experiment with rice (OM5451) was set up to evaluate the effect of biogas effluent and melaleuca biochar on CH₄ and N₂O flux under net house conditions. Six treatments with four levels of ground melaleuca biochar were mixed in soil (0, 2, 10, and 20 tons. ha^-1) were applied. The results showed that CH₄ emission from all treatments supplemented with melaleuca biochar was significantly decreased from 29.3 % to 47 % in comparison to control. Moreover, N₂O emission was also reduced from 20 % to 47.7 %. In conclusion, the melaleuca biochar application significantly reduced N₂O and CH₄ emissions while maintaining rice production.