Farm simulation can help adapt dairy production systems to climate change

Authors: Rotz, Clarence - Al; Skinner, Robert; STONER, ANNE - Texas Tech University; HAYHOE, KATHARINE - Texas Tech University

Submitted to: Book Chapter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2015
Publication Date: 1/14/2016
Citation: Rotz, C.A., Skinner, R.H., Stoner, A.M., Hayhoe, K. 2016. Farm simulation can help adapt dairy production systems to climate change: J. Hatfield and D. Fleisher. Advances in Agricultural Modeling, Volume 7. Madison, WI: American Society of Agronomy. 34p.

Interpretive Summary: An assessment of climate change effects on dairy farm production is complex, requiring integration of the generally positive effects of elevated carbon dioxide on crop photosynthesis and yield with the potentially positive or negative effects of temperature and precipitation changes on crop and animal performance. To capture this complexity, models are often used to evaluate climate change impacts on agriculture. Further studies are needed to assess the impact of projected climate changes on dairy farms throughout the United States and to help adapt our farms to those changes. A climate model was used to predict future weather for this century for major dairy regions across the country. Farm simulations were then done to evaluate the effects of this future weather on the performance, economics and environmental impacts of dairy farms in Pennsylvania, New York, Wisconsin, Idaho, California and Texas. Our analyses indicate that forage production may benefit from projected climate change in many dairy regions as long as adequate water is available to meet crop needs. Corn grain production may be decreased in many areas unless varieties can be adapted to warmer climates. With a longer growing season in the northern United States, management practices such as double cropping with winter small grain crops may further increase forage production. Through changes in crop varieties, planting and harvest dates, and other management practices, dairy farms can maintain sustainable production systems. In our analysis, we have studied farms with relatively minor management changes, and more major changes may occur. It is difficult to predict what dairy production may look like by the end of the century. Whether the changes to come are major or minor, climate and farm simulation models provide tools to help us prepare and adapt to the changes to come.

Technical Abstract: Climate change is projected to affect many aspects of dairy production including growing season length, crop growth processes, harvest timing and losses, heat stress on cattle, nutrient emissions and losses, and ultimately farm profitability. Recent historical weather and future climate projections for higher and lower future scenarios were downscaled from the National Center for Atmospheric Research Coupled Climate System Model version 4 (CCSM4) using the Asynchronous Regional Regression Model. The Integrated Farm System Model (IFSM) was then used to simulate representative dairy farms over 25-yr periods using recent, mid and end of century climate data. Base farms reflected current production practices with recent weather in southern Pennsylvania, northern New York, central Wisconsin, southern Idaho, central California, and central Texas. We explored management changes to adapt the farms to future climate by modifying crop varieties and planting and harvest dates, and for the Pennsylvania, Wisconsin and Idaho locations, double cropping of small grain silage and corn silage was included for the end of the century simulations. Responses to projected climate change varied across the six locations, but several common trends were found. For most locations, projected climate changes improved forage production, but decreased corn grain production. Higher temperatures and changes in precipitation patterns increased gaseous emissions and nutrient losses from farms. For most scenarios, adaptations in management were able to maintain farm profitability. This simulation study illustrates how climate and farm simulation models can provide valuable information for planning and adapting our dairy farms to changing climate.