Nitrapyrin Mitigates Nitrous Oxide Emissions, and Improves Maize Yield and Nitrogen Efficiency under Waterlogged Field

In order to explore the effects of nitrapyrin (N-Serve) application on greenhouse gas emission and nitrogen (N) leaching of a waterlogged maize (<i>Zea mays</i> L.) field, we investigated the effects of applying nitrapyrin on soil ammonium (NH₄⁺-N) and nitrate nitrogen (NO₃⁻-N) content, nitrous oxide (N₂O) fluxes, and the warming potential (GWP_N₂O) in a waterlogged maize field. The design included three treatments: waterlogging treatment with only urea application (V-3WL), waterlogging treatment with urea and nitrapyrin application (V-3WL+N), and no waterlogging treatment applying only urea (CK). Our results revealed that waterlogging led to the increase of nitrate concentrations across the soil profile, thus potentially increasing N leaching and decreasing N use efficiency. The accumulated N₂O emissions increased significantly in waterlogged plots compared to control plots, and maximum N₂O emission fluxes occurred during the process of soil drying after waterlogging; this resulted in an increase in GWP_N₂O and N₂O greenhouse gas intensity (GHGI_N₂O) by 299% and 504%, respectively, compared to those of CK. However, nitrapyrin application was able to reduce N₂O emissions. Nitrapyrin application was also good for decreasing GWP_N₂O and GHGI_N₂O by 34% and 50%, respectively, compared to V-3WL. In addition, nitrapyrin application was conducive to reduce N leaching and improve N use efficiency, resulting in a yield increase by 34%, compared to that of V-3WL. The application of nitrapyrin helped to mitigate agriculture-source greenhouse effects and N leaching induced by waterlogging, and was a high N-efficient fertilizer method for a waterlogged field.