A meta-analysis to examine whether nitrification inhibitors work through selectively inhibiting ammonia-oxidizing bacteria

• Published in: Frontiers in microbiology Vol. 13; p. 962146
• Main Authors: Lei, Jilin, Fan, Qianyi, Yu, Jingyao, Ma, Yan, Yin, Junhui, Liu, Rui
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 19.07.2022
• Subjects: ammoxidation; DMPP; edaphic conditions; Microbiology; microorganism; nitrous oxide
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.962146

Nitrification inhibitor (NI) is often claimed to be efficient in mitigating nitrogen (N) losses from agricultural production systems by slowing down nitrification. Increasing evidence suggests that ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) have the genetic potential to produce nitrous oxide (N 2 O) and perform the first step of nitrification, but their contribution to N 2 O and nitrification remains unclear. Furthermore, both AOA and AOB are probably targets for NIs, but a quantitative synthesis is lacking to identify the “indicator microbe” as the best predictor of NI efficiency under different environmental conditions. In this present study, a meta-analysis to assess the response characteristics of AOB and AOA to NI application was conducted and the relationship between NI efficiency and the AOA and AOB amo A genes response under different conditions was evaluated. The dataset consisted of 48 papers (214 observations). This study showed that NIs on average reduced 58.1% of N 2 O emissions and increased 71.4% of soil NH 4 + concentrations, respectively. When 3, 4-dimethylpyrazole phosphate (DMPP) was applied with both organic and inorganic fertilizers in alkaline medium soils, it had higher efficacy of decreasing N 2 O emissions than in acidic soils. The abundance of AOB amo A genes was dramatically reduced by about 50% with NI application in most soil types. Decrease in N 2 O emissions with NI addition was significantly correlated with AOB changes ( R 2 = 0.135, n = 110, P < 0.01) rather than changes in AOA, and there was an obvious correlation between the changes in NH 4 + concentration and AOB amo A gene abundance after NI application ( R 2 = 0.037, n = 136, P = 0.014). The results indicated the principal role of AOB in nitrification, furthermore, AOB would be the best predictor of NI efficiency.