Soil is a critical life-supporting compartment of the biosphere. Soil models have long played an important role in quantifying and predicting soil processes and ecosystem services. However, a new generation of soil models based on a systems approach comprising physical, chemical and biological processes is needed to address knowledge gaps. This symposium  deals with challenges and perspectives in modeling soil processes. We welcome contributions that address major scientific gaps in describing soil processes, inter-compare soil models, evaluate model uncertainty, discuss data requirements, and link soil with other process models such as climate, land surface, ecological, crop and contaminant models.