Treatment of irrigation water using plasma involves a series of electrochemical reactions that forms NOx- in water working as a fertilizer in plant cultivation. Here we report the results of an experimental study of the effects of different discharge conditions especially discharge frequency on air phase gliding arc discharge. The results show that, the low-frequency system consumed nearly three times more energy than the high-frequency system when generating the same NOx- production rate in water; gas flow rate has strong influence on the low-frequency system while slight influence on the high-frequency system; high-frequency discharge can generate much larger plasma area to promote electrochemical reactions resulting more NOx- produced in water. Frequency from 5 kHz to 80 kHz does not significantly influence on the nitrogen fixation of gliding arc. (C) The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.