Characterization and influence of biochars on nitrous oxide emission from agricultural soil

► C content of biochar increased with temperature but O and H content decreased. ► Biochars produced at 200-600 °C reduced N2O emissions from agricultural soil. ► PAHs in biochars (300-400 °C) seem a dominant factor for the reduced N2O emission. ► Phenolic compounds in biochars (<300 °C) may reduce N2O emission.