Finding a Suitable CO2 Response Algorithm for Crop Growth Simulation in Germany

A soil-crop-environment model was used to describe the combined effects of atmospheric carbon dioxide concentration [CO2], temperature and precipitation on different agricultural crop species. Within this model, a set of algorithms describing CO2 response to photosynthesis and crop water use efficiency, which were different in complexity and parameter requirements, was tested for its suitability to explain crop growth responses and soil water dynamics observed over six years in a crop rotation (winter barley, sugar beet and winter wheat) with two cycles under normal and elevated atmospheric CO2 levels (FACE experiment; Weigel and Dammgen, 2000).