BACKGROUND: Among the biomass conversion techniques of livestock manure, composting process is a method of decomposing organic matter through micro-organisms, and converting it into fertilizer in soil. The aerobic composting process is capable of treating cow manure in large quantities, and produces greenhouse gas like CO2 and N2O, although had economical benefit. Therefore, using the activated rice hull biochar, which is a porous material, it is intended to mitigate the greenhouse gases, and produce compost that had high quality. Objective of this experiment was estimated with CO2 and N2O emissions through composting process of cow manure with different cooperated biochar contents.METHOD AND RESULT : The treatments of activated rice hull biochar were set at 0%, 5%, 10% and 15%, respectively, during composting cow manure. The CO2 emissions in the control was 534.7 L kg-1, but was 385.5 L kg-1 at 15% activated rice hull biochar. Reduction efficiency of CO2 emissions was estimated to be 28%. N2O emission was 0.28 L kg-1 in the control, but was 0.03 L min-1 at 15% of activated rice hull biochar, estimating about 89% reduction efficiency.
CONCLUSION: Greenhouse gas emissions during the composting process of cow manure can be reduced by mixing with 15% of activated rice hull biochar for eco-friendly compost production.