New finding of Trichoderma asperellum in decreasing soil N2O emission

Abstract

Background: Global warming caused by greenhouse gas emissions affects sustainable human development. Agricultural practices are important source of greenhouse gases (GHG). Nitrous oxide (N2O) contributes greatly to farming GHG. It is important to find a potential and practical biological technique that mitigate N2O emissions in an environment friendly way. Methods: N2O-inhibiting fungi were isolated and identified in the lab. The fungi were added into the soil and placed in the incubator and interval gas sampling was analyzed by gas chromatograph. Results: Fungus coding Z17 was identified molecularly with the same evolutionary branch on the phylogenetic tree with Trichoderma asperellum by BLAST comparison on NCBI GenBank. In the lab simulation, the N2O emission flux was decreased by 28.18–47.16% by inoculating Trichoderma asperellum with 106 cfu·g−1, 5 × 106 cfu·g−1 and 107 cfu·g−1 fungal spores in the soil compared to the control. Conclusions: The N2O-inhibiting fungus Z17 was identified as Trichoderma asperellum, capable of suppressing N2O emissions from soil with at least 106 CFU·g−1 soil. The best N2O-inhibiting effect was on day 9 of inoculation into soil because most of the fungal numbers were present in soil.