Journal article

Authors list: Cao, Miaomiao; Li, Yong; Zhang, Yuxuan; Yu, Debang; Uwiragiye, Yves; Wang, Jing; Jing, Hang; Tang, Quan; Qian, Yinfei; Elrys, Ahmed S; Cheng, Yi; Cai, Zucong; Xu, Minggang; Müller, Christoph

Publication year: 2025

Journal: Agriculture, Ecosystems and Environment

Volume number: 377

ISSN: 0167-8809

eISSN: 1873-2305

DOI Link: https://doi.org/10.1016/j.agee.2024.109278

Publisher: Elsevier

Abstract: 
Autotrophic (AN) and heterotrophic (HN) nitrification pathways regulate soil nitrogen availability and are responsible for nitrate losses to the environment. It is often assumed that HN plays a more important role than AN in acidic soils. However, so far, no detailed study has attempted to identify how pH affects the relative importance of gross rates of AN (GAN) and HN (GHN) in acidic soils. Combining N-15 dilution technique with acetylene inhibition along a natural soil pH gradient of 3.7-6.9, we revealed a negative exponential relationship between GHN/GAN ratio and soil pH, with a threshold of pH=4.5 =4.5 and 4.7 with and without the addition of ammonium, respectively. Variations of fungal and ammonia-oxidizing archaea (AOA) abundances along the pH gradient further confirmed the existence of this threshold. Soil nitrification was predominantly fungi-driven HN below the threshold and AOA-driven AN above the threshold. Overall, we provide evidence that a pH threshold controls the dominant nitrification pathway in acidic soils by affecting specific microbes, which could be important for predicting soil nitrification patterns and developing effective mitigation techniques to promote nitrogen availability and decrease nitrogen loss risk.

Harvard Citation style: Cao, M., Li, Y., Zhang, Y., Yu, D., Uwiragiye, Y., Wang, J., et al. (2025) pH threshold in controlling dominant nitrification pathway in acidic soils, Agriculture, Ecosystems and Environment, 377, Article 109278. https://doi.org/10.1016/j.agee.2024.109278

APA Citation style: Cao, M., Li, Y., Zhang, Y., Yu, D., Uwiragiye, Y., Wang, J., Jing, H., Tang, Q., Qian, Y., Elrys, A., Cheng, Y., Cai, Z., Xu, M., & Müller, C. (2025). pH threshold in controlling dominant nitrification pathway in acidic soils. Agriculture, Ecosystems and Environment. 377, Article 109278. https://doi.org/10.1016/j.agee.2024.109278