Greenhouse gas emissions from a wheat–maize double cropping system with different nitrogen fertilization regimes.

Here, we report on a two-years field experiment aimed at the quantification of the emissions of nitrous oxide (N₂O) and methane (CH₄) from the dominant wheat–maize double cropping system in North China Plain. The experiment had 6 different fertilization strategies, including a control treatment, recommended fertilization, with and without straw and manure applications, and nitrification inhibitor and slow release urea. Application of N fertilizer slightly decreased CH₄ uptake by soil. Direct N₂O emissions derived from recommended urea application was 0.39% of the annual urea-N input. Both straw and manure had relatively low N₂O emissions factors. Slow release urea had a relatively high emission factor. Addition of nitrification inhibitor reduced N₂O emission by 55%. We conclude that use of nitrification inhibitors is a promising strategy for N₂O mitigation for the intensive wheat–maize double cropping systems. [Copyright &y& Elsevier]