Agricultural systems play a central role in the earth system. They provide us with food, but they also contribute to the greenhouse effect via the emission of CO2, CH4 and N2O, can cause soil degradation, may change water cycles and will be strongly affected by climate change. All these processes are strongly interconnected and therefore need to be addressed in a consistent approach. In this publication, such a consistent global modelling framework is presented, focussing on the simulation of global crop yields and resulting N2O emissions. The existing agro-ecosystem model DayCent was parameterised to calculate global yields for major crop types. Simulation results show that the model is capable of reproducing the effects of climate, soil and management on crop production. For addressing global N2O and NO emissions, both a statistical model (based on an extensive literature database) and a process-based approach (using the DayCent model) have been developed. This book is addressed to scientists and students interested in large scale environmental modelling, and to anyone who wants to learn more about the methods and uncertainties of global models.
