The crucial role of integrative economic analysis in evaluating agricultural BMPs: A framework and case study of controlled drainage with sub-irrigation

This study presents the Holistic Economic Assessment Framework for Best Management Practices (HEAF-BMP). This new approach comprehensively evaluates net economic returns from agricultural BMP adoption by integrating multiple environmental impacts. We demonstrate its utility by comparing controlled drainage with sub-irrigation (CDSI) versus free drainage (FD) on a southern Ontario farm. Our findings reveal that focusing on individual environmental impacts, subsurface nutrient loss, surface runoff, or greenhouse gas emissions can dramatically shift economic outcomes, with potential differences reaching $440.6 per hectare. When all impacts were considered together, CDSI adoption resulted in an average annual cost ($176.7 per hectare) for farmers, reflecting both higher infrastructure and maintenance costs and reductions in certain years. The government perspective also revealed an average annual cost ($91.8 per hectare), largely due to the high social costs associated with environmental trade-offs. These results underscore the importance of going beyond single-impact analyses; although CDSI effectively reduced subsurface nutrient loss, it also increased nutrient loss through surface runoff and nitrous oxide emissions. By capturing both positive and negative externalities within a unified economic framework, HEAF-BMP provides clearer guidance for farmers, policymakers, and researchers seeking to balance agricultural productivity, environmental stewardship, and economic viability.