Nitrous oxide emissions and N-cycling gene abundances in a drip-fertigated (surface versus subsurface) maize crop with different N sources

Summary

Abstract Surface drip fertigation has demonstrated promising results regarding the mitigation of nitrous oxide (N 2 O) emissions. The use of subsurface irrigation may offer the possibility of reducing these emissions further due to the modification of the soil moisture profile and N allocation, both of which affect the biochemical processes leading to N 2 O fluxes. However, the mitigation potential of subsurface irrigation combined with different mineral nitrogen (N) fertilizers (ammonium or nitrate-based, use of nitrification inhibitors) still needs to be evaluated. To respond to this need, a 2-year field experiment was set up in central Spain to test two different drip-fertigation systems (surface and subsurface at 30 cm depth) and four N fertilization treatments (control, calcium nitrat