Development and test of a crop growth model for application within a Global Change decision support system

When examining potential impacts of Global Change on water resources on the regional scale, spatial and temporal changes in crop water and nitrogen demand are of fundamental significance. State-of-the-art crop growth models are powerful tools to assess the response of crops to altered environmental conditions and cultivation practices. In this paper, the process-based, object-oriented and generic DANUBIA crop growth model is presented. To evaluate the performance of the model, a validation analysis is carried out by comparing modelled data with various field measurements of sugar beet, spring barley, maize, winter wheat and potato crops. Model performance statistics show that crop growth is efficiently simulated. The closest agreement between measured and modelled biomass and leaf area index is achieved for sugar beet and winter wheat. Additionally, the response of the model to changed nitrogen availability caused by cultivation practices is analysed and reveals good results. The results suggest that the model is a suitable tool for numerically assessing the consequences of Global Change on biomass production, water and nitrogen demand, taking into account the complex interplay of water, carbon and nitrogen fluxes in agro-ecosystems.