The Agricultural Model Exchange Initiative

Process-based crop simulation models are increasingly popular tools to analysis and predict the response of agricultural systems to climatic, agronomic and, more recently genetic, factors. The diversity of models in use illustrates the success of crop modeling. For instance, in it is current work the AgMIP Wheat team uses 42 different wheat models. Several groups in AgMIP have reported large uncertainty in climate impact studies, which is calling for more systematic model intercomparisons and improvements at the process level. However, the limited possibilities of model components (algorithms) and code exchange between platforms/models hinders such work. Collaborative efforts between crop physiologists, crop modelers, and software engineers are urgently needed to ease the integration in crop models of new knowledge in plant and soil sciences. To this end, several leading groups in the field have recently liaised to form the Agricultural Model Exchange Initiative (AMEI). AMEI is an open initiative that aims to address different challenges for exchanging model units at different granularities (from individual processes to whole plant) between modeling frameworks by (1) defining standards to describe model units and composition exchange format based on a declarative representation; (2) including unit tests with invariants and shared standard parametrizations; and (3) developing a web-platform to publish, document, and exchange the model units. We will provide a conceptual and technical overview of the state of the work and give practical examples of successful component exchange between different frameworks