Reducing Nitrous Oxide Emissions with Sub-surface drip Irrigation and Split Fertilizer Applications

摘要

Of the three biogenic greenhouse gases, (i.e., carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), N2O is considered to be most potent. The overall goal of this study was to determine detailed time series of soil N2O fluxes at crucial management events for tomatoes subjected to deficit subsurface drip irrigation (SDI) regime and multiple fertilizer application rates. Flux chamber measurements were conducted using an EPA approved methodology to collect air samples that were ultimately analyzed using a Gas Chromatograph. Significant differences in the N2O fluxes due to the irrigation and/or fertilizer treatments generally peaked within two hours after fertilizer application. Overall, there was a moderate positive correlation between the amount of N20-N emitted and the fertilizer applied (r= 0.64) and with the volume of water applied (r= 0.74). More importantly, these emission rates were relatively constant in both years at 0.002 kg N20-N per ha per IbofNfertilizer and would imply that the incremental addition of both fertilizer and water through SDI could be highly efficient management practices to minimize the N20 emissions in tomato cropping systems.