EXPLORING POLICY ALTERNATIVES FOR CONTROLLING NITRATE POLLUTION FROM NEW MEXICO’S DAIRIES
Jingjing Wang, Janak Raj Joshi
Consolidation in livestock production generates higher average net farm incomes due to economies of scale. However, it also brings manure disposal problems. New Mexico ranks number one in the nation in dairy herd size. Dairy manure is a significant source of nitrates and improper management of manure from the state’s large dairy farms can produce adverse environmental and health effects. In this study, we use a combination of life cycle assessment (LCA), cost-benefit analysis (CBA), and sensitivity analysis to investigate policies for controlling nitrogen pollution from large dairy farms in New Mexico. We first construct an integrated farm-level model that is suitable to investigate alternative policies for controlling nitrate pollution from a typical large dairy farm in New Mexico. Based on this typical dairy farm, we then conduct the LCA and CBA analyses of dairy manure management under three cases: direct land application of dairy manure (DLA), anaerobic digestion of dairy manure (AD), and anaerobic digestion of dairy manure coupled with microalgae cultivation (ADMC). Four environmental impacts of the alternative manure management cases are assessed in the LCA analysis and net benefits of each case are evaluated in the CBA analysis under a baseline scenario and different incentive-based policy scenarios. We also conduct sensitivity analysis of cropland availability, rangeland availability, and policy strength to check the robustness of our results. We find that, for a typical large dairy farm in New Mexico, the DLA case is the least sustainable with regard to any of the environmental impacts. AD is most profitable in the baseline, tax credit, and carbon credit scenarios while ADMC is most profitable in the presence of a market for nutrient credits. We also discuss the most effective approaches and policy tools for manure management on large dairy farms of New Mexico.
Keywords: Dairy, CAFOs, livestock manure, nitrates, algae, bioenergy, life cycle assessment, cost-benefit analysis, sensitivity analysis