Abstract
Abstract
Soil chemical properties and microbiome composition impact N2O emission potential, but the relative importance of these factors as determinants of N2O emission in denitrifying systems is rarely tested. In addition, previous linkages between microbiome composition and N2O emission potential rarely demonstrate causality. Here, we determined the relative impact of bacteriome composition (i.e., soil extracted bacterial cells) and soil water extract (i.e., water extractable chemicals and particles below 0.22 µm) on N2O emission potential utilizing an anoxic cell-based assay system. Cells and water extract for assays were sourced from soils with contrasting N2O/N2O + N2 ratios, combined in various combinations and denitrification gas production was measured in response to nitrate addition. Analysis of 16S amplicon sequencing data revealed similarity in composition between extracted and parent soil bacteriomes. Average directionless effects of cell and water extract on N2O/N2O + N2 (Cell: ∆0.17, soil water extract: ∆0.22) and total N2O hypothetically emitted (Cell: ∆2.62 µmol-N, soil water extract: ∆4.14 µmol-N) across two assays indicated water extract is the most important determinant of N2O emissions. Independent pH differences of just 0.6 points impacted N2O/N2O + N2 on par with independent water extract differences, supporting the dominance of this variable in previous studies. However, impacts on overall N2O hypothetically emitted were smaller, suggesting that soil pH manipulation may not necessarily be a successful approach to mitigate emissions. In addition, we observed increased N2O accumulation and emission potential at the end of incubations concomitant with predicted decreases in carbon (C) availability, suggesting that C limitation increases N2O emission transiently with the magnitude of emission dependent on both chemical and bacteriome controls.
Funder
New Zealand Fund for Global Partnerships in Livestock Emissions Research
Publisher
Springer Science and Business Media LLC
Subject
Soil Science,Agronomy and Crop Science,Microbiology
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献