Integrating a spatial micrometeorological model into the risk assessment for arable crops in hilly terrain

Arable crops in hilly terrain may experience additional abiotic stress over crops growing in the plain, which affects crop establishment and productivity. We aim to predict risks and sustainability of crops in hilly terrain for current and future climates. In the STAMINA project we include a proper micrometeorological model (MM) to simulate the effects of terrain on atmospheric variables and their impact on crop growth. A generic crop growth model (CGM) is connected to the MM model, simulating growth and development of an arable crop. The model system estimates the distributed components of the soil water and energy balance with reference to standard weather variables, crop and topographic characteristics. Finally, specific risk indicators, e.g. crop water stress index (CWSI) and thermal stress index (TSI), are calculated to characterize yield reduction and to test mitigation options. The model was successfully calibrated for cereals and sugar beet. Here, we give an overview of this new model and present some results for a 5-year simulation scenario for northern Europe, in which we quantified the effects of terrain (slope and aspect) on meteorological variables and crop yields. The effect of topography on productivity was considerable: south-facing aspects were beneficial for winter wheat in wet years (+2.3 t DM ha(-1)), similar effects were seen for sugar beet.