Analysis of beneficial management practices to mitigate environmental impacts in dairy production systems around the Great Lakes

Authors: KIM, DAESOO - University Of Arkansas; STODDART, NICK - University Of Arkansas; Rotz, Clarence - Al; VELTMAN, KARIN - University Of Michigan; CHASE, LARRY - Cornell University; COOPER, JOYCE - University Of Washington; INGRANHAM, PETE - Applied Geosolutions, Llc; IZAURRALDE, R. CESAR - University Of Maryland; JONES, CURTIS - University Of Maryland; GAILLARD, RICHARD - University Of Wisconsin; AGUIRRE-VILLEGAS, HORACIO - University Of Wisconsin; LARSON, REBECCA - University Of Wisconsin; RUARK, MATT - University Of Wisconsin; SALAS, WILLIAM - Applied Geosolutions, Llc; JOLLIET, OLIVIER - University Of Michigan; THOMA, GREGORY - University Of Arkansas

Submitted to: Agricultural Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2019
Publication Date: 7/22/2019
Citation: Kim, D., Stoddart, N., Rotz, C.A., Veltman, K., Chase, L., Cooper, J., Ingranham, P., Izaurralde, R., Jones, C.D., Gaillard, R., Aguirre-Villegas, H., Larson, R.A., Ruark, M., Salas, W., Jolliet, O., Thoma, G.J. 2019. Analysis of beneficial management practices to mitigate environmental impacts in dairy production systems around the Great Lakes. Agricultural Systems.176:1-12. https://doi.org/10.1016/j.agsy.2019.102660.
DOI: https://doi.org/10.1016/j.agsy.2019.102660

Interpretive Summary: Milk consumption is well-known to benefit human health and nutrition, but dairy production systems are also known to be a contributor to environmental issues including climate change, aquatic and terrestrial eutrophication, and acidification. Therefore, the U.S. dairy industry has committed to environmental leadership with efforts to produce dairy products in sustainably efficient ways. To meet economic and environmental sustainability goals, a number of mitigation technologies and practices in both crop and animal production have been recommended. We evaluated the effectiveness of multiple management practices across a comprehensive suite of environmental impacts for distinct dairy farm types in different locations using life cycle assessment. Whole-farm mitigation strategies of combined feed, field and manure management demonstrate significant potential to reduce overall carbon footprint as well as other environmental impacts. This study shows the benefit of alternative dairy production practices on individual impact indicators, and illustrates the need for comprehensive assessments considering the trade-offs among them.

Technical Abstract: The influence of farm-specific beneficial management practices (BMPs) on a set of comprehensive environmental impacts was characterized and quantified for two representative dairy farms in the Great Lakes region (a large 1,500-cow farm in New York (NY) and a small 150-cow farm in Wisconsin (WI)). Comparative benefits or drawbacks of the effect of adoption of selected management scenarios to environmental impacts were estimated by coupling the output from the Integrated Farm System Model (IFSM) as lifecycle inventory data for SimaPro©. Greenhouse gas emissions of the baseline scenario at the farm gate were 0.980 kg CO2-eq/kg fat and protein corrected milk (FPCM) for the large farm with a range from 0.727 - 1.03 kg CO2-eq/kg FPCM across all BMPs. The small farm baseline emitted 1.22 kg CO2-eq/kg FPCM with a range from 0.974 - 1.30 kg CO2-eq/kg FPCM across all BMPs. The small dairy farm in WI generated a consistently larger carbon footprint than the large dairy farm in NY due to different feeds fed leading to greater enteric methane (CH4) emissions and greater nitrous oxide (N2O) emissions from the bedded pack housing facility for young stock. Whole-farm mitigation strategies of combined feed, field and manure management demonstrate significant potential to reduce overall carbon footprint as well as other environmental impact indicators. The assessments of selective impact categories such as fossil energy use, water use, land occupation, aquatic eutrophication, terrestrial acidification, respiratory effects, human toxicity, and ecotoxicity are discussed and highlight hot spots relevant for sustainable dairy farm management. Normalization analysis indicates that eutrophication potential is the largest relative impact profile, which suggests that efforts to mitigate eutrophication can achieve relatively greater environmental impact reduction. Although this study addressed the beneficial adaptation of sustainable dairy production practices on individual impact profile, it is not that simple when comprehensive environmental impacts are considered as there are trade-offs between them.