3.3 Contribution of microorganisms to N2O emission
Compared with the control without biological inhibitors (control treatment), the treatment with bacterial inhibitors (streptomycin treatment) and fungal inhibitors (cycloheximide treatment) significantly reduced soil N2O emission (P < 0.05) (Fig. 3a). The N2O emission after bacterial inhibitor treatment was significantly higher than that after fungal inhibitor treatment (P < 0.05), and significantly lower after fungal and bacterial inhibitor treatment (P < 0.05). The N2O production was reduced to 30.9% by fungal inhibitor treatment, 45.4% by bacterial inhibitor treatment, and 23.7% by fungal and bacterial inhibitor treatment as compared to that in the control treatment. These results suggeste d that fungi may play a larger role in N2O production in lawn soil.
Moreover, the contribution rate of fungi to N2O emission was significantly higher than that of bacteria and other microorganisms (P < 0.05) (Fig. 3b). Fungi contributed to 45% of total N2O emission, while bacterial contribution only reached 68% of that of the fungi. This also indicated that the contribution of fungi to N2O emission was significantly higher than that of bacteria in lawn soil.