School of Environment, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huai River Water Environmental Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, Henan, People's Republic of China.
Environ Sci Pollut Res Int. 2020 Oct;27(29):36160-36171. doi: 10.1007/s11356-020-09696-y. Epub 2020 Jun 18.
Understanding the relationship between nitrogen (N) cycle and N transformation-related functional genes is crucial to reduce N loss during composting process. Urease inhibitor (UI) is widely used to reduce N loss in agriculture. However, the effects of UI on N transformation and related N functional genes during composting have not been well investigated. The goal of this study was to investigate the effects of a urease inhibitor (UI) on N functional genes and bacterial community succession during pig manure composting. Results showed that the addition of UI decreased the ammonium N content during the thermophilic stage and notably increased the total N and nitrite N contents of the final compost. The UI significantly decreased the abundances of amoA, nirS, nirK, and nosZ during the initial composting stage, while the opposite trend was observed at the maturation stage. Bacterial community richness and diversity were increased after the UI amendment, but the relative abundance of the phyla Firmicutes and Proteobacteria significantly decreased compared with control during the thermophilic stage. Redundancy analysis indicated that the evaluated environmental factors and bacterial community showed a cumulative 94.7% contribution to the total variation in N functional genes. In summary, UI addition is a recommended method for N conservation during composting, but the added forms of UI, such as delayed addition, combined with adsorbing materials, or microorganism inoculant, should be further evaluated.
了解氮（N）循环与 N 转化相关功能基因之间的关系，对于减少堆肥过程中的 N 损失至关重要。脲酶抑制剂（UI）广泛应用于农业以减少 N 的损失。然而，UI 对堆肥过程中 N 转化和相关 N 功能基因的影响尚未得到充分研究。本研究旨在探讨脲酶抑制剂（UI）对猪粪堆肥过程中 N 功能基因和细菌群落演替的影响。结果表明，添加 UI 可降低高温阶段的铵态氮含量，并显著增加最终堆肥的总氮和亚硝态氮含量。UI 在初始堆肥阶段显著降低了 amoA、nirS、nirK 和 nosZ 的丰度，而在成熟阶段则出现相反的趋势。UI 处理后细菌群落丰富度和多样性增加，但与对照相比，厚壁菌门和变形菌门的相对丰度在高温阶段显著降低。冗余分析表明，评估的环境因素和细菌群落对 N 功能基因的总变异有 94.7%的累积贡献。总之，UI 添加是堆肥过程中 N 保存的一种推荐方法，但应进一步评估 UI 的添加形式，如延迟添加、与吸附材料或微生物接种剂结合使用。
