[A review on development of stable isotope technique in the studies of N 2 O formation mechanism].

As one of three major greenhouse gases, nitrous oxide (N ₂ O) has solicited substantial attention. Stable isotope has been widely used to explore the sources of N ₂ O emissions. Here, we briefly introduced the microbial processes involved in N ₂ O emissions, and the main influencing factors. We further summarized the development of N ₂ O isotope signature of δ ¹⁵ N, δ ¹⁸ O and SP (site preference of ¹⁵ N in different positions of N ₂ O molecule) in exploring the N ₂ O formation mechanism. The application of these techniques, especially the SP values, is still at the primary stage in China. Therefore, this paper focused on the development of the isotope ratios analysis in partitioning N ₂ O sources from foreign countries, and put forward suggestions on the future research in China.