Environmental Impacts of Dairy Production Systems in the Changing Climate of the Northeast

To meet the nutritional needs of a growing population, dairy producers must increase milk production while minimizing farm environmental impacts. As we look to the future, management practices must also be adapted to maintain production under projected climate change. To plan for the future, better information is needed on practices that can reduce emissions from the farm and adapt to changes in the climate while maintaining or improving production and profitability.

What did we do?

We conducted a comprehensive assessment of the effects of climate change on both the productivity and environmental performance of farms as influenced by strategies to reduce emissions and adapt to the changing climate. Production systems were evaluated using three representative northeastern dairy farms: a 1500-cow farm in New York, a 150-cow farm in Wisconsin and a 50-cow farm in southern Pennsylvania. A cradle-to-farm gate life cycle assessment was conducted using farm-scale process-based modeling and climate projections for high and low emission scenarios. Environmental considerations included the carbon footprint of the milk produced and reactive N and P losses from the farms.

What we have learned?

We found that the environmental impact of the three representative dairy farms generally increased in the near future (2050) climate if no mitigation measures were taken. Overall, feed production was maintained as decreases in corn grain yield were compensated by increases in forage yields. Adaptation of the cropping system through changes in planting and harvest dates and corn variety led to a smaller reduction in corn grain yield, but the detrimental effects of climate change could not be fully negated. Considering the increased forage yield, total feed production increased except for the most severe projected climate change. Adoption of farm-specific beneficial management practices substantially reduced the greenhouse gas emissions and nutrient losses of the farms in current climate conditions and stabilized the environmental impact in future climate conditions, while maintaining feed and milk production (See Figure 1 for example results).

Figure 1. Carbon footprint, reactive nitrogen footprint and P loss in recent (2000) and future (2050) climate conditions (RCP4.5 and RCP8.5) for a 1500-cow farm in New York with baseline and Best Management Practice (BMP) scenarios, with and without crop system adaptions in 2050. Error bars represent the standard deviation of IFSM simulations for 3 climate scenarios per RCP. Unadapt = not adapted cropping system. Adapt = adapted cropping system.
Figure 1. Carbon footprint, reactive nitrogen footprint and P loss in recent (2000) and future (2050) climate conditions (RCP4.5 and RCP8.5) for a 1500-cow farm in New York with baseline and Best Management Practice (BMP) scenarios, with and without crop system adaptions in 2050. Error bars represent the standard deviation of IFSM simulations for 3 climate scenarios per RCP. Unadapt = not adapted cropping system. Adapt = adapted cropping system.

The take-home message is that with appropriate management changes, our dairy farms can become more sustainable under current climate and better prepared to adapt to future climate variability.

Future plans

A more comprehensive life cycle assessment is being done by linking the output of the farm model with life cycle assessment software. The process level simulation of the farm provides inventory information for an inclusive life cycle assessment with multiple environmental considerations. This integrated software will provide a more complete sustainability assessment of the potential benefits of alternative management strategies for both now and the future.

Authors

Karin Veltman, University of Michigan; C. Alan Rotz, USDA-ARS; Larry Chase, Cornell University; Joyce Cooper, Washington State University; Chris Forest, Penn State University; Pete Ingraham, Applied GeoSolutions; R. César Izaurralde, University of Maryland; Curtis D. Jones, University of Maryland; Robert Nicholas, Penn State University; Matt Ruark, University of Wisconsin; William Salas, Applied GeoSolutions; Greg Thoma, University of Arkansas; Olivier Jolliet, University of Michigan.

Additional information

Information on the Integrated Farm System Model is available in the reference manual:

Rotz, C., Corson, M., Chianese, D., Montes, F., Hafner, S., Bonifacio, H., Coiner, C., 2018. The Integrated Farm System Model, Reference Manual Version 4.4. Agricultural Research Service, USDA. Available at: https://www.ars.usda.gov/northeast-area/uppa/pswmru/docs/integrated-farm-system-model/#Reference.

Information on the analysis of Best Management Practices on northeastern dairy farms is available in:

Veltman, K., C. A. Rotz, L. Chase, J. Cooper, P. Ingraham, R. C. Izaurralde, C. D. Jones, R. Gaillard, R. A. Larsson, M. Ruark, W. Salas, G. Thoma, and O. Jolliet. 2017. A quantitative assessment of beneficial management practices to reduce carbon and reactive nitrogen footprints and phosphorus losses of dairy farms in the Great Lakes region of the United States. Agric. Systems 166:10-25.

Acknowledgements

This work was supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2013-68002-20525. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer.

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