Location: Water Management ResearchTitle: Subsurface drip irrigation reduced nitrous oxide emissions in a pomegranate orchard
|ZEJIANG, CAI - Beijing Academy Of Agricultural Sciences|
|DUAN, YINGHUA - Beijing Academy Of Agricultural Sciences|
|QIN, RUIJUN - Oregon State University|
|TIRADO-CORBALA, REBECCA - University Of Puerto Rico|
Submitted to: International Journal of Environmental Science and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2019
Publication Date: 3/1/2019
Citation: Gao, S., Hendratna, A., Zejiang, C., Duan, Y., Qin, R., Tirado-Corbala, R. 2019. Subsurface drip irrigation reduced nitrous oxide emissions in a pomegranate orchard. International Journal of Environmental Science and Development. 10(3):79-85. https://doi.org/10.18178/ijesd.2019.10.3.1151.
Interpretive Summary: Nitrous oxide (N2O) is a potent greenhouse gas, and agriculture is a major source for its production through fertilization. Effective field management practices should be developed as mitigation strategies. This research determined if high-frequency subsurface drip irrigation and fertilization can reduce N2O emissions in comparison with traditional surface drip irrigation. After two years of data collection in a pomegranate orchard, the subsurface drip resulted in substantially and consistently lower N2O emissions due to dry surface and fertilizer application in subsurface soil. The emission data were positively correlated to or supported by the N2O production in soil profile. Results also showed that higher N2O emissions were from higher N application rate, thus increasing N use efficiency by applying N based on crop demand can also reduce N2O emissions. The findings apply to all irrigated agriculture.
Technical Abstract: Soil fertilization is one of the major sources for nitrous oxide (N2O) emissions, and soil moisture is among the most important factors affecting its production. Thus, one of the important mitigation strategies in semiarid or arid regions is through irrigation and/or fertigation management. The objective of this research was to evaluate the effects of different drip irrigation methods and N application levels on N2O emissions. Nitrous oxide emission flux and N2O concentration in soil profile were measured in a pomegranate field for two growing seasons under two irrigation systems [subsurface drip irrigation (SDI) at ~0.5 m depth and traditional surface drip irrigation (DI)], and three N application rates (50%, 100%, and 150% of current practice rate). Both years’ data showed that N2O emissions have a high and positive correlation with N fertilization events and application levels. Nitrous oxide emissions from DI at 100% and 150% N levels were over an order of magnitude higher compared to those from SDI based on the data of the first year. Data from the second year confirmed the first year’s findings of high emissions from DI. A positive linear correlation between the N2O emission flux and N2O concentration in soil-gas phase was identified that supported emission data. This research demonstrated that although N fertilization is a major cause for N2O emissions, subsurface drip irrigation/fertigation can lead to a significant emission reduction in addition to other benefits, such as increased water and nutrient use efficiencies, and reduced weed pressure.