Jiang Liping, Yu Jie, Wang Shanyun, Wang Xiaomin, Schwark Lorenz, Zhu Guibing
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Glob Chang Biol. 2023 Apr;29(7):1984-1997. doi: 10.1111/gcb.16586. Epub 2023 Jan 23.
The contribution of agriculture to the sustainable development goals requires climate-smart and profitable farm innovations. Increasing the ammonia fertilizer applications to meet the global food demands results in high agricultural costs, environmental quality deterioration, and global warming, without a significant increase in crop yield. Here, we reported that a third microbial ammonia oxidation process, complete ammonia oxidation (comammox), is contributing to a significant ammonia fertilizer loss (41.9 ± 4.8%) at the rate of 3.53 ± 0.55 mg N kg day in agricultural soils around the world. The contribution of comammox to ammonia fertilizer loss, occurring mainly in surface agricultural soil profiles (0-0.2 m), was equivalent to that of bacterial ammonia oxidation (48.6 ± 4.5%); both processes were significantly more important than archaeal ammonia oxidation (9.5 ± 3.6%). In contrast, comammox produced less N O (0.98 ± 0.44 μg N kg day , 11.7 ± 3.1%), comparable to that produced by archaeal ammonia oxidation (16.4 ± 4.4%) but significantly lower than that of bacterial ammonia oxidation (72.0 ± 5.1%). The efficiency of ammonia conversion to N O by comammox (0.02 ± 0.01%) was evidently lower than that of bacterial (0.24 ± 0.06%) and archaeal (0.16 ± 0.04%) ammonia oxidation. The comammox rate increased with increasing soil pH values, which is the only physicochemical characteristic that significantly influenced both comammox bacterial abundance and rates. Ammonia fertilizer loss, dominated by comammox and bacterial ammonia oxidation, was more intense in soils with pH >6.5 than in soils with pH <6.5. Our results revealed that comammox plays a vital role in ammonia fertilizer loss and sustainable development in agroecosystems that have been previously overlooked for a long term.
农业对可持续发展目标的贡献需要气候智能型且有利可图的农场创新。增加氨肥施用以满足全球粮食需求会导致农业成本高昂、环境质量恶化和全球变暖，而作物产量却没有显著增加。在此，我们报告称，第三种微生物氨氧化过程，即全程氨氧化（comammox），导致全球农业土壤中氨肥大量流失（41.9±4.8%），流失速率为3.53±0.55毫克氮/千克·天。全程氨氧化对氨肥流失的贡献主要发生在农业土壤表层（0 - 0.2米），与细菌氨氧化（48.6±4.5%）相当；这两个过程都比古菌氨氧化（9.5±3.6%）重要得多。相比之下，全程氨氧化产生的一氧化二氮较少（0.98±0.44微克氮/千克·天，11.7±3.1%），与古菌氨氧化产生的量相当（16.4±4.4%），但显著低于细菌氨氧化产生的量（72.0±5.1%）。全程氨氧化将氨转化为一氧化二氮的效率（0.02±0.01%）明显低于细菌（0.24±0.06%）和古菌（0.16±0.04%）氨氧化。全程氨氧化速率随土壤pH值升高而增加；土壤pH值是唯一显著影响全程氨氧化细菌丰度和速率的理化特性。在pH值>6.5的土壤中，以全程氨氧化和细菌氨氧化为主导的氨肥流失比pH值<6.5的土壤更为严重。我们的研究结果表明，全程氨氧化在农业生态系统的氨肥流失和可持续发展中起着至关重要的作用，而这一点在长期以来一直被忽视。
