Date of Graduation
7-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Public Policy (PhD)
Degree Level
Graduate
Department
Public Policy
Advisor/Mentor
Popp, Jennie
Committee Member
Kerr, Brinck
Second Committee Member
Thoma, Greg
Keywords
Dairy manure management; Decision support tool; Economic analysis; Multicriteria analysis; Nutrient redistribution; Policy Design
Abstract
U.S. dairy production has consolidated into fewer but much larger operations, intensifying manure management challenges, resulting in environmental externalities associated with air and water quality. Despite decades of regulatory requirements and voluntary incentive programs, pollution from large-scale dairies remains a challenge, reflecting the complexity of manure management systems (MMSs) and existing policy limitations. This dissertation explores economic, environmental, and logistical outcomes across farm-level dairy MMSs and how policy instrument choices may affect management decisions and behavior changes related to improving environmental outcomes in high-density dairy regions. The first manuscript introduces the manure management and technology (ManureTech) Decision Support Tool (DST) for Dairy, a process-based model using a multicriteria decision analysis framework that evaluates 92 predefined MMS scenarios across eighteen economic, environmental, and technological performance metrics. Applied to a representative dairy with 900 milking cows in Colorado’s Platte Drainage region, results show that no single MMS consistently outperformed all others across all metrics and scenario rankings change substantially as priorities change. The second manuscript applies the DST to a representative dairy with 872 milking cows in Idaho’s Magic Valley region to evaluate how solid-liquid separation (SLS) technologies of varying efficiencies affect system-wide outcomes. Results show that lower-efficiency SLS technologies result in favorable costs while providing substantial carbon emissions reductions and land application logistical improvements compared to the scenario without separation. Advanced systems further improve these outcomes but at substantially higher costs. Lagoon sludge accumulation is the dominant logistical constraint, with consistent improvements across increasing SLS efficiencies. The third manuscript uses the Idaho case study, examing how two policy instruments – cost-share subsidy on SLS technologies and manure transport payments – affect farm-level outcomes and government expenditures. Uniform cost-share payments reduce capital costs but likely fail to incentivize adoption of higher-performing technologies. Transport payments may incentivize the use of manure as fertilizer for non-livestock crop farmers and increase dairy revenues, but may require potentially prohibitive government spending to satisfy manure nutrient redistribution needs for the region. This dissertation demonstrates that effective dairy manure management requires whole-system evaluation, consideration of multiple performance objectives, and policy instrument designs that align expected behavior changes with policy goals.
Citation
Scott, E. E. (2026). Bridging Science and Policy in Dairy Manure Management Using a Multicriteria Decision Support Tool. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6380
