The approaches based on natural abundance N₂O stable isotopes are often applied for the estimation of mixing proportions between various N₂O-producing pathways as well as for estimation of the extent of N₂O reduction to N₂. But such applications are associated with numerous uncertainties; hence, their limited accuracy needs to be considered. Here we present the first systematic validation of these methods for laboratory and field studies by applying the ¹⁵N gas-flux method as the reference approach. Besides applying dual-isotope plots for interpretation of N₂O isotopic data, for the first time we propose a three dimensional N₂O isotopocule model based on Bayesian statistics to estimate the N₂O mixing proportions and reduction extent based simultaneously on three N₂O isotopic signatures (δ¹⁵N, δ¹⁵N^SP, and δ¹⁸O). Determination of the mixing proportions of individual pathways with N₂O isotopic approaches often appears imprecise, mainly due to imperfect isotopic separation of the particular pathways. Nevertheless, the estimation of N₂O reduction is much more robust, when applying an optimal calculation strategy, typically reaching an accuracy of N₂O residual fraction determination of about 0.15.

中文翻译：

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用于N ₂ O产生源分配和N ₂ O还原估算的N ₂ O同位素方法–在实验室和现场研究中使用¹⁵ N气流量法进行验证

基于自然丰度N ₂ O稳定同位素的方法通常用于估算各种N ₂ O产生途径之间的混合比例以及估算N ₂ O还原为 N _2的程度。但是，这种应用会带来许多不确定性。因此，需要考虑其有限的精度。在这里，我们通过应用¹⁵ N气体通量法作为参考方法，对这些方法进行实验室和现场研究进行了首次系统验证。除了应用双同位素图来解释 N ₂ O同位素数据，首次提出了一种三维Ñ ₂ ö isotopocule基于贝叶斯统计来估计模型Ñ ₂ ö混合在三个同时基于比例和还原程度Ñ ₂ ö同位素特征（δ ¹⁵ Ñ，δ ¹⁵ Ñ ^SP和 δ ¹⁸ ö）。确定各个通道与N ₂ O的混合比例同位素方法常常显得不精确，这主要是由于特定途径的同位素分离不完善所致。然而， 当应用最佳计算策略时，对N ₂ O还原量的估计更为稳健，通常可达到约0.15的N ₂ O残留分数确定精度。