An Integrated Social and Ecological Modeling Approach to the Impacts of Agricultural Conservation Practices on Water Quality

The progress of human societies has been highly dependent on agriculture, the expansion and intensification of which parallel the growth of human population and its footprint. However, the ecosystems upon which agriculture depends are constrained.

Therefore, to move toward sustainability, we must employ policies that provide benefits at different scales and preserve the integrity of existing resources. According to the Food, Agriculture, Conservation and Trade Act of 2008, enhancing the quality of the environment and resource base is a key agricultural sustainability goal. The adoption of conservation practices is regarded as an effective strategy to enhance water quality and improve agricultural sustainability by increasing system resilience.

The central objective of this research is to model the diffusion and adoption of conservation practices by farmers and its impacts on downstream water quality, with the goal of increasing agricultural sustainability by understanding and optimizing the relationships among water quality, agro-environmental policy, and farmer adoption of conservation practices. To abate the damage on ecosystem services, policies have focused on a range of solutions and institutions, including the development and application of conservation practices intended to alleviate negative impacts on water resources.

To study the effectiveness of these solutions, this research examines the coupled natural and human system using a social model (Agent-based model, ABM) and a biophysically based watershed model (Soil and Water Assessment Tool, SWAT) to study farmer responses to agro-environmental policies of the United States, as well as the impacts of those responses on water quality. This integrated model system also considers feedback from water quality outcomes to policy makers and farmers through revision and implementation of different agro-environmental policies. In this study, farmers’ reactions to policies intended to incentivize conservation practices and their attitudes towards adoption are critical determinants of the spatial distribution of these practices, and therefore, to the water quality outcome.

By understanding and modeling the interactions among adopters and non-adopters and simultaneously analyzing the effects of these interactions on water quality, I will build the knowledge necessary to evaluate the water quality results from alternative policies related to conservation investments. This project will constitute an important step in understanding the effects of different policy approaches on the adoption of conservation practices and their impacts on downstream water quality.