Climate-Smart Agriculture (CSA) is increasingly framing the studies that apply crop simulation models (CSMs). This approach that combines sustainable intensification of production, climate change adaptation and mitigation places new demands on the use of models and the processes and variables they describe. CSA-related model applications require both reliable estimates of crop responses to changing growing conditions and accurate estimates of rising number of variables and processes with variable management options. For example, soil carbon balances are increasingly important to be able to assess the CO 2 sequestration potential of agricultural soils. CSMs should thus cover carbon, water and nutrient cycles and their interconnections with sufficient accuracy.