Sprinkler Irrigation Is Effective in Reducing Nitrous Oxide Emissions from a Potato Field in an Arid Region: A Two-Year Field Experiment

In arid and semi-arid regions, water-saving irrigation is the primary mode of local agricultural production. Since the chemical fertilizer is the principal source of nitrous oxide (N2O) emissions, we present results from a two-year (2016–2017) field experiment on a potato field to verify the general influence of water-saving irrigation on N2O emissions. A split-plot experiment was established with two irrigation systems and two fertilizer treatments, which give a total of four treatments. Two different irrigation systems were investigated: (i) flood irrigation with nitrogen fertilizer (NF-FI) combined with a control without any fertilizer (C-FI) and (ii) overhead sprinkler irrigation with a nitrogen fertilizer (NF-SI) accompanied with a control without any fertilizer (C-SI). The N2O emissions of the fertilizer treatment were greater than those of the control under each irrigation system. In plots where the fertilizers were applied, using overhead sprinkler irrigation reduced the average cumulative N2O emissions between 40.72% and 59.65% compared with flood irrigation. This was mainly due to the lower amount of water applied and the lower availability of NO3−-N and NH4+-N of soil associated with an overhead sprinkler irrigation. This work shows that the overhead sprinkler irrigation is an effective strategy to use to save water and mitigate emissions of the atmospheric pollutants N2O in comparison to flood irrigation.