Anaerobic ammonium oxidation in agricultural soils-synthesis and prospective

• Published in: Environmental pollution (1987) Vol. 244; pp. 127 - 134
• Main Authors: Nie, San'an, Zhu, Gui-Bing, Singh, Brajesh, Zhu, Yong-Guan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2019
• Subjects: Agricultural soils; Agriculture; Ammonium Compounds - chemistry; Anaerobiosis; Anammox; Denitrification; N loss; Oxic/anoxic interface; Oxidation-Reduction; Rhizosphere; Soil Microbiology; Rhizosphere; Anammox; N loss; Agricultural soils; Oxic/anoxic interface
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2018.10.050

Denitrification is considered as the dominant nitrogen (N) removing pathway, however, anaerobic oxidation of ammonium (anammox) also plays a significant part in N loss in agricultural ecosystems. Large N inputs into agricultural soils may stimulate the growth of anammox bacteria, resulting in high activity and diversity of anammox bacteria and subsequent more N loss. In some specific niches, like oxic-anoxic interface, three processes, nitrification, anammox and denitrification couple with each other, and significant anammox reaction could be observed. Soil parameters like pH, dissolved oxygen, salinity, oxidation-reduction potential (ORP), and substrate concentrations impact the anammox process. Here we summarize the current knowledge on anammox activity and contribution to N loss, abundance and diversity of anammox bacteria, factors affecting anammox, and the relationship between anammox and other N loss pathways in agricultural soils. We propose that more investigations are required for (1) the role of anammox to N loss with different agricultural management strategies; (2) microscale research on the coupling of nitrification-anammox-denitrification, that might be a very complex process but ideal model for further studies responsible for N cycling in terrestrial ecosystems; and (3) new methods to estimate differential contributions of anammox, codenitrification and denitrification in total N loss in agricultural ecosystems. New research will provide much needed information to quantify the contribution of anammox in N loss from soils at landscape, ecosystem and global scales. [Display omitted] •About 5–10% of the applied fertilizers was lost by anammox in agricultural soils.•Terrestrial soils possess a high diversity and abundance of anammox bacteria.•The oxic/anoxic interfaces in the agricultural soil are hotspots for anammox.•The redox gradient area is the main coupling nitrification-anammox-denitrification.•Anammox, codenitrification and denitrification need further estimation.