N 2 O emissions and NO 3 − leaching from two contrasting regions in Austria and influence of soil, crops and climate: a modelling approach

Abstract

National emission inventories for UN FCCC reporting estimate regional soil nitrous oxide (N 2 O) fluxes by considering the amount of N input as the only influencing factor for N 2 O emissions. Our aim was to deepen the understanding of N 2 O fluxes from agricultural soils, including region specific soil and climate properties into the estimation of emission to find targeted mitigation measures for the reduction of nitrogen losses and GHG emissions. Within this project, N 2 O emissions and nitrate (NO 3 − ) leaching were modelled under spatially distinct environmental conditions in two agricultural regions in Austria taking into account region specific soil and climatic properties, management practices and crop rotations. The LandscapeDNDC ecosystem model was used to calculate N 2 O emissions and NO 3 − leaching reflecting different types of vegetation, management operations and crop rotations. In addition, N input and N fluxes were assessed and N 2 O emissions were calculated. This approach allowed identifying hot spots of N 2 O emissions. Results show that certain combinations of soil type, weather conditions, crop and management can lead to high emissions. Mean values ranged from 0.15 to 1.29 kg N 2 O–N ha −1 year −1 (Marchfeld) and 0.26 to 0.52 kg N 2 O–N ha −1 year −1 (Grieskirchen). Nitrate leaching, which strongly dominated N-losses, often reacted opposite to N 2 O emissions. Larger quantities of NO 3 − were lost during years of higher precipitation, especially if winter barley was cultivated on sandy soils. Taking into account the detected hot spots of N 2 O emissions and NO 3 − leaching most efficient measures can be addressed to mitigate environmental impacts while maximising crop production. © 2018, The Author(s).