Economic forces continue to drive long-term trends increasing the size of agricultural operations. These trends support expansion of CAFO (confined animal feeding operations) livestock systems as adding more animals means more milk/meat output to generate more cash flow/revenues; and to spread fixed costs and management over more units of output. Increasing CAFO size increases manure volumes and Clean Water Act (CWA) regulatory issues that arise when manure volumes exceed the land base (crop nutrient demand) required to efficiently use manure nutrients without significant environmental losses.
We have built a farm-scale, infinite time-horizon optimization model, to aid farmers' decisions on crop/rotation planning and nutrient sources applications. The objective is to minimize annual operational cost while respecting environmental constraints such as Phosphorus and Soil Loss. Our model can be used to evaluate the impacts of new manure separation techniques in the long term, or to recommend new such technological development/research. It can be easily modified to be a short-term planning for 1-2 rotational time period (8-16 years). We capture the environmental factors by interfacing a sophisticated environmental model, SNAP+ which uses the RUSLE2 for computing soil loss, in a way that new knowledge/updates in these models can automatically translate into our optimization models. The model is flexible that can be extendable by incorporating more specific details; for example, location-specific crop rotation requirement or crop yield.