Abstract #97

# 97
Environmental benefits of alternatives in dairy farm management in the changing climate of the northeastern United States.
K. Veltman1, A. Rotz*2, L. Chase3, J. Copper4, C. Forest5, P. Ingraham6, C. Izaurralde7, C. Jones7, R. Nicholas5, M. Ruark8, W. Salas6, G. Thoma9, O. Jolliet1, 1University of Michigan, Ann Arbor, MI, 2USDA-ARS, University Park, PA, 3Cornell University, Ithaca, NY, 4University of Washington, Seattle, WA, 5Penn State University, University Park, PA, 6Applied Geosolutions, Durham, NH, 7University of Maryland, College, Park, MD, 8University of Wisconsin, Madison, WI, 9University of Arkansas, Fayetteville, AR.

To meet the nutritional needs of a growing population, dairy producers must increase milk production while minimizing farm-gate environmental impacts. As we look to the future, management practices must also be adapted to projected climate change. A comprehensive assessment was made of the effects of climate change on both the productivity and environmental performance of farms as influenced by strategies to adapt to the changing climate. Production systems were evaluated using 3 representative northern US dairy farms: a 1500-cow farm in New York, a 150-cow farm in Wisconsin, and a 50-cow farm in southern Pennsylvania. The farms were simulated using farm-scale process-based modeling and climate projections for high and low greenhouse gas emission scenarios. Environmental impacts of the farms, which included farm-gate reactive nitrogen and carbon footprints and phosphorous runoff, generally increased in the near future (2050) if no mitigation measures were taken. Overall, feed production was maintained as decreases in corn grain yields were compensated by increases in forage yields. Adaptation of the cropping systems through changes in planting and harvest dates and crop varieties reduced the reduction in corn grain yields, but the detrimental effects of climate change were not fully negated. Adoption of farm-specific beneficial management practices, including changes in diet, manure management and cropping practices, substantially reduced the greenhouse gas emissions and nutrient losses of dairy farms in current climate conditions and stabilized the environmental impact in future climate conditions, while maintaining feed and milk production. This modeling exercise illustrates that more sustainable dairy production systems can be maintained in the future climate of the Northeast with appropriate management changes.

Key Words: Integrated Farm System Model, climate change, farm management