Nitrous Oxide Emissions and Its Influencing Factors in Spring Corn Fields Mulched with Plastic Film on the Loess Plateau

The static gas chamber technique was used to investigate nitrous oxide(N2O)emission fluxes and its main influencing factors in a spring corn field under different cultivation methods on the Loess Plateau, Northwestern China. The experiment treatments included two plastic film mulch(no mulch, T1 and mulch, T2)under the same fertilization and three fertilization(high inorganic nitrogen, T3; inorganic nitrogen+organic fertilizer, T4; and no fertilizer, T5)under the same mulch conditions. Results showed that nitrogen application was the main factor affecting the N2O emissions, where T3T4T5. The peak emissions occurred 4~10 d after fertilization. In nitrogen treatments, N2O fluxes showed three emission peaks in the season, all occurring after nitrogen application and rainfall. Film mulching did not significantly affect N2O emissions. The N2O emission fluxes were significantly positively correlated with soil NO-3(P0.01). In the dryland corn field on the Loess Plateau, soil nitrification was a main contributor to N2O emissions but denitrification played a relatively small role in the N2O emissions.