Evaluating water quality regulation as a driver of farmer behavior: a social-ecological systems approach

Water quality policy for agricultural lands seeks to improve water quality by changing farmer behavior. We investigate farmer behavior in three water quality regimes that differ by rule structure to examine the fit and interplay of each policy within its social-ecological context, important aspects for improving water quality. Vermont, USA’s practice-based policy requires the adoption of specific practices, whereas New Zealand’s Lake Taupo and Lake Rotorua performance-based policies require farmers to meet a numeric limit for nutrient loss on their farm. Across the three regions we interviewed 38 farmers to elicit mental models of nutrient management changes. We utilized the social-ecological systems (SES) framework to guide mental model elicitation, drawing on farmers’ perceptions of the SES to identify salient aspects for behavior. Mental models were grouped by region and analyzed using network analysis. Farmers in all regions self-report high levels of behavior change and cite the policies as key drivers of behavior. This suggests that each policy fits in that it is achieving desired behavior change. However, different behavioral patterns emerged across the regions that we hypothesize have implications for biophysical fit: structural changes dominate in Vermont (e.g., buffers) and system changes in Taupo (e.g., switch from dairy support to beef cattle). The interplay of the policy in each setting, such as with incentive programs in Vermont and a market for nitrogen in Taupo, contributed to the different behavioral patterns. Additionally, access to capital in some form is required for farmers to achieve changes associated with higher biophysical fit. The social fit of the policies also varied, evidenced by dramatic upheaval in Taupo to mostly neutral perceptions of the policy in Vermont. We conclude that regions considering a shift to water quality rules for farms should carefully consider behavioral dynamics in policy design to achieve water quality goals.