Measurement of N2o Emissions From Drip Irrigated Soils in a Pomegranate Orchard.

Agriculture is identified as a major contributor to greenhouse gas N₂O emissions. Developing a sustainable crop production system should consider increasing N use efficiency and minimizing losses including N₂O emissions.  Pomegranate is a new emerging crop in the San Joaquin Valley of California because of the health benefits of the fruits. In the process of developing a productive orchard, subsurface drip irrigation (SDI) is investigated for high efficient water and nutrient use in comparison with surface drip irrigation (DI).  We hypothesize that SDI will reduce N₂O emissions because of more efficient water use and plant N uptake based on previous tests for annual crops.  The objective of this research is to determine if SDI is also efficient in reducing N₂O emissions in perennial field.  Static flux chambers with automatic sampling feature were constructed for field measurements. Data show significantly higher N₂O emissions from DI than SDI plots. Higher N₂O concentrations were determined in DI soil profile compared to SDI.  The relationship between soil N status and N₂O emissions are examined. This research is to provide an assessment on potentially environmental benefit of SDI in a newly established pomegranate orchard.