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ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Terrestrial Microbiology

This article is part of the Research TopicMicrobial Contributions to Organic Waste Recycling and Detoxification during Composting and Post-ApplicationView all articles

Effects of long-term biochar application combined with chemical fertilization on the nitrifier community in tobacco plantation soil

Provisionally accepted
Di  XuDi Xu1,2Hang  LuoHang Luo1,2Tianyi  HeTianyi He1,2Yang  EYang E1,2*Junyi  GaoJunyi Gao3
  • 1Liaoning Biochar Engineering Technology Research Center, Shenyang Agricultural University, Shenyang, China
  • 2National Biochar Institute, shenyang, China
  • 3China Tobacco Guizhou Industrial Co Ltd Bijie Company, Bijie, China

The final, formatted version of the article will be published soon.

Soil nitrogen (N) plays a critical role in plant nutrition and is regulated by the process of nitrification. Biochar can enhance soil N concentration and is hypothesized to influence nitrification, particularly when applied in combination with chemical fertilizers. Although,several studies have documented the effects of biochar and fertilizer combinations on nitrifying microbial communities, the underlying mechanisms remain poorly understood. In this study, the abundances of ammonia-oxidizing archaea (AOA) in the BT3 (15 t/ha) and BT5 (40 t/ha) treatments, and ammonia-oxidizing bacteria (AOB) in the BT4 (20 t/ha) treatment, were significantly higher than in fertilizer-only treatments. In contrast, nitrite-oxidizing bacteria (NOB) in the BT2 (5 t/ha) treatment exhibited the most significant difference (p < 0.05). Compared to the control (BT1), the relative abundances of AOB (Nitrosomonas; 51.74%) and NOB (Nitrolancea; 62.26%) increased significantly (p < 0.05) with higher application rates of biochar fertilizer concentration. Metabolic profiling and molecular docking simulations precisely demonstrated that 2,2-diethylacetamide (DEA), a compound structurally analogous to oxalate, interacts with the active site of pyruvate kinase, thereby affecting the glycolysis pathway. A subsequent potting experiment confirmed that DEA treatment increased pyruvate kinase gene expression (from 1.37 to 11.03; p < 0.05), soil pyruvic acid concentration (from 1.73 to 21.65; p < 0.05), and nitrifier abundance (from 0.20% to 0.56%; p < 0.05). Furthermore, soil copper (Cu; R2 = 0.21, p < 0.05), molybdenum (Mo; R2 = 0.53, p < 0.05), zinc (Zn; R2 = 0.37, p < 0.05), and total organic carbon (TOC; R2 = 0.24, p < 0.05) content were negatively correlated with nitrifier abundance as biochar-fertilizer application increased. This indicates that DEA derived from biochar, in conjunction with soil elemental composition, collectively influences nitrifying communities. The relationships between biochar-fertilizer application and nitrifier communities established in this study will inform precise application strategies to enhance nitrogen use efficiency in crops.

Keywords: biochar, chemical fertilizer, Nitrification, ammonia oxidizing bacteria, Molecular docking analysis

Received: 24 Oct 2025; Accepted: 17 Nov 2025.

Copyright: © 2025 Xu, Luo, He, E and Gao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Yang E, eyang@syau.edu.cn

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