As the main component of proteins, nitrogen (N) is required by all living organisms. Nitrogen is abundant in the atmosphere, which is 79% N, but mostly as a stable, unreactive gas (N2). Reactive N that is available for plant growth is often in short supply, however. In agricultural systems, addition of fertilizer N can increase crop production and as a result, improve human nutrition. On the other hand, excess fertilizer N can have deleterious effects on air and water, and thus on human health.
To guide our understanding of these trade-offs, we have developed a simulation model of cropping systems in north central Iowa to track nitrogen as it cycles between stocks, also known as reservoirs or pools. The model is based on data from research in this region. The model will allow us to run experiments and ask ‘What-if’ questions about the effects of crop and soil management options, and climate change, on N cycling. The goals are to develop N budgets and understand principles that guide management for crop productivity, soil conservation, and nitrate pollution reduction in streamflow. The experiments will also provide insight into how management at the local level influences regional and global nitrogen cycling.
Instructions: Look for the model using the model name “N Cycling In Ag Systems” or by clicking on the Social and Eco Dynamics category (left side) and then finding the model.
Returning users may access the model more directly here.