Estimating site-specific environmental impacts of agriculture with PALMS

After years of gearing his research primarily toward the scientific audience, John Norman decided that practitioners of agriculture deserved a robust, science-based tool to fulfill their needs related to productivity, profit, and environmental impact. The result of this effort is the Precision Agricultural-Landscape Modeling System (PALMS): a collection of biophysical models linked together to work at the scale at which humans manage the agricultural environment. PALMS uses a point-column energy-water-mass model to simulate vertical exchanges in the atmosphere-plant-soil system on a grid, and links the grid cells together with runoff, erosion/sedimentation, and phosphorus transport models. In this way, not only is the landscape's spatial variability modeled, but landscape interactions can be simulated, as conditions in one part of the landscape can affect other parts of the landscape. Agricultural management is a key part of the model, so that the economic and environmental impacts of crop and tillage selection can be compared to each other. Several examples of the economic and environmental effects of differing management will be shown.