Reducing N2O Emissions From Orchard Using Subsurfce Drip Irrigation.

Agricultural soil is the major source for N2O emissions. Minimizing N2O emissions along with increasing N use efficiency, reducing leaching loss, maintaining crop economic yield, and quality can lead to increased sustainability of crop production. The main objective of this research is to evaluate the effects of subsurface drip irrigation (SDI) and surface drip irrigation (DI) on N2O emission in a pomegranate orchard. Static flux chamber method was used to measure N2O emission flux from research plots under the two irrigation systems with three N application rates (50%, 100%, and 150% plant requirement). The first year data show clearly that N2O emissions from SDI plots were significantly lower than DI, especially at higher N application rates. A positive linear correlation between the N2O emission flux and N2O concentration in soil-gas phase was identified. This research shows that although fertilized agricultural soil is a major source of N2O emissions, significant emission reduction can be achieved by using subsurface drip irrigation, which also shows the advantage for increasing water and N use efficiencies in comparison with surface drip irrigation. The second year data are being collected. Data appear to confirm the first year findings.