Impacts of Elevated Atmospheric CO2 and N Fertilization on N2O Emissions and Dynamics of Associated Soil Labile C Components and Mineral N in a Maize Field in the North China Plain

The elevated atmospheric CO2 concentration (eCO2) is expected to increase the labile C input soil, which may stimulate microbial activity and soil N2O emissions derived from nitrification denitrification. However, few studies studied effect of eCO2 on maize field under free-air enrichment (FACE) conditions in warm temperate zone. Here, we report a study conducted during 12th summer season long-term eCO2, aiming investigate emissions. Moreover, tested zero conventional N fertilization treatments, with being grown either or ambient (aCO2). We hypothesized that would be increased due changes mineral C-deposition, larger when was combined fertilization. also measured activities some extracellular enzymes, could reflect status. results showed that, seasonal by 12.4–15.6% (p < 0.1) 13.8–18.5% 0.05), respectively. significantly 33.1–36.9% 17.1–21.8%, Furthermore, combination intensity marginal significant mostly lower water regime after year. Dissolved organic (DOC) biomass (MBC) at most major stages, particularly tasseling stage growth period eCO2. In contrast, decrease rhizospheric soils. C-related enzymes were higher stage, coincided concurrent DOC MBC conclude increases emissions, causes fertilization, but extent influenced environmental factors, especially water, great extent. highlighted urgent need monitor production pathways various hydrothermal regimes