Instantaneously Identifying Biological Sources of Nitrous Oxide Flux from Agricultural Soils via Position Specific Nitrogen Stable Isotope Compositions

摘要: Nitrous oxide (N 2 O), a greenhouse gas, is produced by multiple biological reactions but their relative contributions in agricultural soils is unknown, preventing loss minimization. We hypothesized that creating favorable environmental conditions for one of these processes, denitrification, will lead to enhanced N 2 O loss. This was achieved in a field study by adding water to create an anerobic soil environment of 80% water filled pore space and monitoring N 2 O flux using an automated chamber system connected to a cavity laser absorption spectroscopy system with capabilities to measure site-specific nitrogen stable isotope compositions of N 2 O. We predicted that differences would indicate the biological sources of N 2 O. Results showed that biological processes contributing to N 2 O flux were (etc) driven by water application, natural precipitation events, and changes in soil temperature. Site-specific ẟ 15 N …