Climate change and N2O emissions from South West England grasslands: A modelling approach.

Unravelling the impacts of climate change on agriculture becomes increasingly important, as the rates and magnitude of its effects are accelerating. Current estimates of the consequences of climate change on nitrous oxide (N 2 O) emissions remain largely uncertain; there is a need for more consistent and comprehensive assessments of this impact. In this study we explored the implications of two IPCC climate change projections (high and medium emissions scenarios) on N 2 O emissions from South West England grasslands for the time slices of a baseline, the 2020s, the 2050s and the 2080s, employing a process-based model (SPACSYS). The model was initially calibrated and validated using datasets collected from three grassland sites of the region. Statistical analysis showed that simulated results had no significant total error or bias compared to measured values. We found a consistent increase in N 2 O emissions of up to 94% under future climate change scenarios compared to those under the baseline, and warming rather than precipitation variability was the overriding factor controlling the N 2 O rise. Modelling fertilizer forms showed that replacing ammonium-nitrate fertilizers with urea or slurry significantly reduced N 2 O emissions (c. 30%). Our study highlights the urgent necessity to adopt viable N 2 O mitigation measures now in order to avoid higher emissions in the future. [ABSTRACT FROM AUTHOR]