Research Progress on N₂O Emissions from Ditches

The ditch, as a special wetland ecosystem, has high redox capacity and greenhouse gas emission potential. Its prominent feature is frequent wetting-drying alternations and also greatly disturbed by human activities. The ditch wetlands is an important source of nitrous oxide (N₂O), while N₂O emissions from ditch wetlands are regulated by various physical and chemical factors, such as hydrological characteristics, vegetation species and loadings of exogenous nutrients. Here the available studies on the quantification approach of N₂O emissions from ditch wetlands done in China and worldwide were synthesized, thereby comparing the N₂O fluxes from rural sewage ditches and agricultural ditches in different regions. Furthermore, the spatial-temporal variations in N₂O emissions from ditch wetlands are analyzed and the key regulators underlying are explored. Overall, further studies are needed to well understand N₂O emissions and the regulators in ditch systems, in particular, investigations on capacity of nitrification-denitrification in ditch wetlands should be strengthened, for the environmental friendly management practices on ditches.