280B
Phylogenetic and functional potential links pH and N2O emissions in pasture soils Md Sainur Samad1, Ambarish Biswas1, Lars R. Bakken, Timothy J. Clough, Cecile A.M. de Klein, Karl G. Richards, Gary J. Lanigan, Sergio E. Morales1* *Correspondence:
[email protected], 1Dept. of Microbiology & Immunology, University of Otago, New Zealand
Introduction Denitrification is mediated by microbial, and physicochemical, processes leading to nitrogen loss via N2O and N2 emissions. Soil pH regulates the reduction of N2O to N2, however, it can also affect microbial community composition and functional potential. Here we simultaneously test the link between pH, community composition, and the N2O emission ratio (N2O/(NO+N2O+N2)) in 13 temperate pasture soils. We hypothesized that the effect of pH on emissions would be linked to changes in whole communities, and not solely to denitrification functional potential.
Objective
To investigate the relationships between phenotypes (emission potential) and genotypes (functional potential and community composition) across 13 soils with varying pH (5.57 - 7.03) representing both Northern and Southern Hemisphere soils
Materials and Methods Ø Ø Ø Ø Ø
Soil samples: Pasture soils from New Zealand and Ireland Gas kinetics and pH measurement of soils qPCR: quantification of denitrification genes 16S rRNA amplicon sequencing of 13 soils: Illumina Miseq (2x150 bp) Metagenomic analysis of 6 samples (LM, TP, HT, MP, JH, SH) using MG-RAST server Figure 1 Geographical location of 13 soil samples. (a) world map, (b) Ireland [Moorepark (MP), Johnstown (JT), Solohead (SH)] and (c) New Zealand [Warepa (WP), Otokia (OT), Wingatui (WT), Tokomairiro (TM), Mayfield (MF), Lismore (LM), Templeton (TP), Manawatu (MM), Horotiu (HR), Te Kowhai (TK)]. (Ref. Samad et al. 2016, PLoS ONE)
Results Figure 4 Taxonomic summary of OTUs significantly associated (p