Nitrous oxide, one of the powerful long-lived greenhouse gases, is emitted mainly through biological processes, especially from fertilized soil. It is critical to partition the contribution of different pathways to N₂O emissions and the relevant characteristics of microbial communities to identify the key N₂O processes. An microcosm was conducted to partition the N₂O emissions from different pathways, and the changes in soil mineral nitrogen and various nitrifiers (amoA bacteria and amoA archaea) and denitrifiers (nirS, nirK, and nosZ) were also determined using qPCR and high-throughput sequencing methods. Different gas inhibitor combinations (i.e., 0.06% acetylene, pure oxygen, 0.06% acetylene in pure oxygen, and pure helium) were used to partition the N₂O pathways. A 5% oxygen treatment, with and without acetylene, was also included so that the N₂O emissions could be measured under lower oxygen partial pressure. Results showed that ammonia-oxidation (AO) and successive nitrifier denitrification (NiD) were the main pathways contributing to N₂O emissions at the earlier period after ammonium sulfate application with the cumulative N₂O emissions accounting for 30.9% and 59.2% of the total N₂O emissions, respectively. The higher NiD N₂O contributions occurred when the soil nitrite concentration appeared higher, especially under the lower oxygen conditions. Higher N₂O emissions from AO and NiD were associated with the compositional proportion of some dominant AOB species. Denitrification contributed more N₂O (63.6%–69.3%) in the later period during incubation, coinciding with the following characteristics for denitrifiers: a) lower nosZ/(nirS + nirK) ratio, b) more diversity in nirS, and c) different proportions of some dominant species in nirK. Our results demonstrated that higher AO and successive NiD were the main N₂O emission pathways, suggesting that controlling the ammonium content and weakening the AO are critical in decreasing N₂O emissions.

一氧化二氮是一种强大的长寿命温室气体，主要通过生物过程排放，特别是从施肥土壤中排放。区分不同途径对N ₂ O排放的贡献和微生物群落的相关特征以识别关键的N ₂ O过程至关重要。进行了一个微观分析，以区分来自不同途径的N ₂ O排放，并且还使用qPCR和高效液相色谱法确定了土壤矿质氮和各种硝化剂（amoA细菌和amoA古细菌）和反硝化剂（nirS，nirK和nosZ）的变化。吞吐量排序方法。使用不同的气体抑制剂组合（例如，0.06％的乙炔，纯氧，纯氧中的0.06％乙炔和纯氦气）分配N₂ O通路。还包括使用和不使用乙炔的5％氧气处理，以便可以在较低的氧气分压下测量N ₂ O排放。结果表明，氨氧化（AO）和连续硝化器反硝化（NiD）是造成施用硫酸铵后较早时期N ₂ O排放的主要途径，累积N ₂ O排放分别占N0.9的30.9％和59.2％。总的N ₂ O排放量。当土壤中亚硝酸盐的浓度较高时，尤其是在较低的氧气条件下，NiD N ₂ O的贡献较高。高N ₂AO和NiD的O排放与某些优势AOB物种的组成比例有关。在孵化后期，反硝化作用贡献了更多的N ₂ O（63.6％–69.3％），这与反硝化剂的以下特征相符：a）较低的nosZ /（nirS + nirK）比，b）nirS的多样性更高，以及c） nirK中某些优势物种的比例不同。我们的结果表明，较高的AO和连续的NiD是主要的N ₂ O排放途径，这表明控制铵含量和弱化AO对于减少N ₂ O排放至关重要。