부산대학교 도서관

Biochar application to soil can reportedly reduce nitrous oxide (N2O) emissions. Conversely, the aged biochar may not suppress N2O emissions from soil because its surface functional groups are oxidized over time. This study aimed to determine the effect of aged biochar materials derived from the coconut shell and rice husk at different pyrolysis temperatures (500°C/800°C) on N2O emissions via denitrification from soil and the surface functional groups of biochar. The results showed that biochar application significantly reduced N2O emissions from soil treated with both raw material biochars. Under the same pyrolysis and oxidation conditions, the coconut-shell biochar was effective than rice-husk biochar in mitigating N2O emission. The higher pyrolysis temperature reduced the functional groups on the surface of biochars, resulting in less N2O emission. However, the oxidation treatment did not affect the C=O functional groups on the surface of 800°C biochars, and therefore N2O emissions from soil treated with these biochars In contrast, H2O2 treatment increased the abundance of C=O functional groups on the surface of the 500°C biochars, resulting in more N2O emissions. In conclusion, the biochars produced at higher pyrolysis temperatures have long-term effects on the mitigation of denitrification-derived N2O emissions from farmland soil.