Cassman NA, Soares JR, Pijl A, Lourenço KS, van Veen JA, Cantarella H, Kuramae EE. Nitrification inhibitors effectively target N
2 O-producing Nitrosospira spp. in tropical soil.
Environ Microbiol 2019;
21:1241-1254. [PMID:
30735001 PMCID:
PMC6850170 DOI:
10.1111/1462-2920.14557]
[Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 01/09/2019] [Accepted: 02/04/2019] [Indexed: 01/01/2023]
Abstract
The nitrification inhibitors (NIs) 3,4-dimethylpyrazole (DMPP) and dicyandiamide (DCD) can effectively reduce N2 O emissions; however, which species are targeted and the effect of these NIs on the microbial nitrifier community is still unclear. Here, we identified the ammonia oxidizing bacteria (AOB) species linked to N2 O emissions and evaluated the effects of urea and urea with DCD and DMPP on the nitrifying community in a 258 day field experiment under sugarcane. Using an amoA AOB amplicon sequencing approach and mining a previous dataset of 16S rRNA sequences, we characterized the most likely N2 O-producing AOB as a Nitrosospira spp. and identified Nitrosospira (AOB), Nitrososphaera (archaeal ammonia oxidizer) and Nitrospira (nitrite-oxidizer) as the most abundant, present nitrifiers. The fertilizer treatments had no effect on the alpha and beta diversities of the AOB communities. Interestingly, we found three clusters of co-varying variables with nitrifier operational taxonomic units (OTUs): the N2 O-producing AOB Nitrosospira with N2 O, NO3 - , NH4 + , water-filled pore space (WFPS) and pH; AOA Nitrososphaera with NO3 - , NH4 + and pH; and AOA Nitrososphaera and NOB Nitrospira with NH4 + , which suggests different drivers. These results support the co-occurrence of non-N2 O-producing Nitrososphaera and Nitrospira in the unfertilized soils and the promotion of N2 O-producing Nitrosospira under urea fertilization. Further, we suggest that DMPP is a more effective NI than DCD in tropical soil under sugarcane.
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