Practical use of components in agro-ecological simulation

Abstract

The use of components to construct simulation models has many advantages and the technique is being used by many modelers. However, in modeling agro-ecological systems, there are some practical problems associated with tightly linked components. The objective of this paper is to present practical solutions to these problems. First, we describe a model of a dairy farm with component models such as livestock, crops, and manure storage. Each component partitions its nutrient inflows into various outflows. The partitioning is driven by the inflows and some process parameters, but is not affected by the state of the component. Thus, linking livestock and crops results in a circular dependency. This dependency is addressed by the introduction of a specialized component. Second, we consider a dynamic model of crop growth, soil water and soil nitrogen. Here, we show that dependencies between component models that arise when we model competition for light, water and nutrients can be reduced by introducing specialized components. In conclusion, the practical problems that have cropped up in our work were successfully addressed and re-use of our component models has become more intuitive.