Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China.
Sci Total Environ. 2023 Dec 1;902:166089. doi: 10.1016/j.scitotenv.2023.166089. Epub 2023 Aug 6.
Nitrogen fertilization has important effects on nitrification. However, how the rate of nitrogen fertilization affects nitrification potential, as well as the communities of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), remains unclear. We performed a large-scale investigation of nitrification potential and ammonia-oxidizer communities in Chinese paddy fields at different nitrogen fertilization rates across different climatic zones. It was found that the nitrification potential at the high nitrogen fertilization rate (≥150 kg N ha) was 23.35 % higher than that at the intermediate rate (100-150 kg N ha) and 20.77 % higher than that at the low rate (< 100 kg N ha). The nitrification potential showed no significant variation among different nitrogen fertilization rates across climatic zones. Furthermore, the AOA and AOB amoA gene abundance at the high nitrogen fertilization rate was 481.67 % and 292.74 % higher (p < 0.05) than that at the intermediate rate, respectively. Correlation analysis demonstrated a significant positive correlation between AOB abundance and nitrification potential. AOA and AOB community composition differed significantly among nitrogen fertilization rates. Moreover, soil NH content, pH, water content, bulk density, and annual average temperature were regarded as key environmental factors influencing the community structure of ammonia-oxidizers. Taken together, the nitrogen fertilization rate had a significant impact on the communities of AOA and AOB but did not significantly alter the nitrification potential. Our findings provide new insights into the impact of nitrogen fertilization management on nitrification in rice paddy fields.
氮肥对硝化作用有重要影响。然而，氮肥施用量如何影响硝化潜能以及氨氧化古菌（AOA）和氨氧化细菌（AOB）的群落结构仍不清楚。我们在不同气候带的中国稻田中，针对不同氮肥施用量下的硝化潜能和氨氧化菌群落进行了大规模调查。结果发现，高氮肥用量（≥150kgNha）下的硝化潜能比中氮用量（100-150kgNha）高 23.35%，比低氮用量（<100kgNha）高 20.77%。氮用量在不同气候带之间的硝化潜能没有显著差异。此外，高氮肥用量下的 AOA 和 AOB amoA 基因丰度分别比中氮用量高 481.67%和 292.74%（p<0.05）。相关性分析表明，AOB 丰度与硝化潜能之间存在显著正相关。AOA 和 AOB 的群落组成在氮用量之间存在显著差异。此外，土壤 NH4+含量、pH 值、含水量、容重和年平均温度被认为是影响氨氧化菌群落结构的关键环境因素。总之，氮用量对 AOA 和 AOB 的群落有显著影响，但对硝化潜能没有显著改变。本研究结果为氮肥管理对稻田硝化作用的影响提供了新的见解。
