P. G. Lakshminarayan

Application of Epic Within an Integrated Modeling System to Evaluate Soil Erosion in the Canadian Prairies

There are approximately 30 million hectares of cultivated land in the three Prairie Provinces of Canada: Alberta, Saskatchewan, and Manitoba. Prairie soils are productive but subject to degradation by wind and water erosion, salinisation, and organic matter decline (Coote, 1984; PFRA, 1990). Climatic factors, soil properties, and either direct (e.g. management) or indirect (e.g. farm policy) human activities interact and dictate, in the end, the extent of degradation.

Compromise solution for economic-environmental decisions in agriculture*

Least-cost production versus the environmental on- and off-site erosion damage of agriculture is evaluated in a policy context for a major Corn Belt watershed. Compromise programming, previously utilized in firm-level multi-criteria decision-making problems, is applied to a regional agricultural production model with environmental policy goal trade-offs. The crop sector model allocates land, water, labor, capital and commodity-program base acres to crop production. Production options include four conservation practices, three tillage methods and several crop rotations. Crop yield and fertilizer levels are dependent upon erosion. Cropping options selected allow for both wind and water erosion. The vector of objectives include three minimization functions: current production cost, future value of productivity loss and sediment damage. Vector optimization technique was used to generate the payoff matrix containing efficient but simultaneously unobtainable solutions. Given the ideal but infeasible solution vector we generated efficient solutions in the compromise subset corresponding to the L1, L2 and L∞ metrics. Trade-off relations were developed using the non-inferior set estimation technique.