Tao Rui, Li Jun, Hu Baowei, Chu Guixin
School of Life Science, Shaoxing University, Shaoxing, 312000, PR China.
School of Life Science, Shaoxing University, Shaoxing, 312000, PR China.
Environ Pollut. 2021 Jan 11;273:116478. doi: 10.1016/j.envpol.2021.116478.
Synthetic inhibitors and organic amendment have been proposed for mitigating greenhouse gas NO emissions. However, their combined effect on the NO emissions and ammonia-oxidizer (ammonia-oxidizing bacteria and archaea, AOB and AOA) communities remains unclear in calcareous soils under climate warming. We conducted two incubation experiments (25 and 35 °C) to examine how NO emissions and AOA and AOB communities responded to organic amendment (urea plus cattle manure, UCM), and in combination with urease (N-(n-butyl) thiophosphoric triamide, NBPT) and nitrification inhibitor (nitrapyrin). The treatments of UCM + nitrapyrin and UCM + nitrapyrin + NBPT significantly lowered total NO emissions by average 64.5 and 71.05% at 25 and 35 °C, respectively, compared with UCM treatment. AOB gene abundance and α-diversity (Chao1 and Shannon indices) were significantly increased by the application of urea and manure (P < 0.05). However, relative to UCM treatment, nitrapyrin addition treatments decreased AOB gene abundance and Chao 1 index by average 115.4 and 30.4% at 25 and 35 °C, respectively. PCA analysis showed that UCM or UCM plus nitrapyrin notably shifted AOB structure at both temperatures. However, fertilization had little effects on AOA community (P > 0.05). Potential nitrification rate (PNR) was greatly decreased by nitrapyrin addition, and PNR significantly positively correlated with AOB gene abundance (P = 0.0179 at 25 °C and P = 0.0029 at 35 °C) rather than AOA (P > 0.05). Structural equation model analysis showed that temperature directly increased AOA abundance but decrease AOB abundance, while fertilization indirectly influenced AOB community by altering soil NH, pH and SOC. In conclusion, the combined application of organic amendment, NBPT and nitrapyrin significantly lowered NO emissions via reducing AOB community in calcareous soil even at high temperature. Our findings provide a solid theoretical basis in mitigating NO emissions from calcareous soil under climate warming.
已有人提出使用合成抑制剂和有机改良剂来减少温室气体一氧化氮（NO）的排放。然而，在气候变暖条件下，它们对石灰性土壤中NO排放和氨氧化菌（氨氧化细菌和古菌，AOB和AOA）群落的综合影响仍不清楚。我们进行了两项培养实验（25℃和35℃），以研究NO排放以及AOA和AOB群落如何响应有机改良剂（尿素加牛粪，UCM），以及与脲酶抑制剂（N-（正丁基）硫代磷酸三酰胺，NBPT）和硝化抑制剂（氯吡脲）的组合。与UCM处理相比，UCM + 氯吡脲和UCM + 氯吡脲 + NBPT处理在25℃和35℃时分别使总NO排放平均显著降低了64.5%和71.05%。施用尿素和粪肥显著增加了AOB基因丰度和α多样性（Chao1和香农指数）（P < 0.05）。然而，相对于UCM处理，添加氯吡脲的处理在25℃和35℃时分别使AOB基因丰度和Chao 1指数平均降低了115.4%和30.4%。主成分分析（PCA）表明，UCM或UCM加氯吡脲在两个温度下均显著改变了AOB结构。然而，施肥对AOA群落影响不大（P > 0.05）。添加氯吡脲显著降低了潜在硝化速率（PNR），并且PNR与AOB基因丰度显著正相关（25℃时P = 0.0179，35℃时P = 0.0029），而与AOA无关（P > 0.05）。结构方程模型分析表明，温度直接增加AOA丰度但降低AOB丰度，而施肥通过改变土壤NH、pH和SOC间接影响AOB群落。总之，即使在高温下，有机改良剂、NBPT和氯吡脲的联合应用通过减少石灰性土壤中的AOB群落显著降低了NO排放。我们的研究结果为缓解气候变暖条件下石灰性土壤的NO排放提供了坚实的理论基础。
