Mitigating nitrous oxide emissions using nitrification and urease inhibitors in corn-based rotations following cover crops termination

Abstract

Cover crops can reduce nitrous oxide (N2O) emissions during the non-growing season and nitrification and urease inhibitors (NUIs) can reduce emissions during the growing season, but these practices have yet to be studied in tandem. The objectives of this study were to 1) quantify N2O emissions from fields under conventional (CONV) and diverse (DIV) rotation over two years and 2) determine the impact of NUIs in both rotations after corn fertilization. The flux-gradient method was deployed in four 4-ha fields using a tunable diode laser trace gas analyzer. The nitrogen use efficiency (NUE) of corn was higher in DIV fields. Compared to the CONV field, the DIV field emitted 9% more N2O, due to higher emissions after the application of fertilizer to corn. The emissions during the 3-week period post fertilizer application to corn accounted for 20-25% of total N2O emissions over two years.