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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #320252
Title: Simulating long-term impacts of cover crops and climate change on crop production and environmental outcomes in the midwestern United States

Author
item BASCHE, ANDREA - Iowa State University
item ARCHONTOULIS, SOTIRIOS - Iowa State University
item Kaspar, Thomas
item Jaynes, Dan
item Parkin, Timothy
item MIGUEZ, FERNANDO - Iowa State University

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2015
Publication Date: 11/28/2015
Citation: Basche, A.D., Archontoulis, S., Kaspar, T.C., Jaynes, D.B., Parkin, T.B., Miguez, F. 2016. Simulating long-term impacts of cover crops and climate change on crop production and environmental outcomes in the midwestern United States. Agriculture, Ecosystems and Environment. 218:95-106. doi: 10.1016/j.agee.2015.11.011.

Interpretive Summary: Climate change will cause significant problems for corn and soybean production in the Midwest. Additionally, the higher temperatures and intense rainfall events that are occurring now may intensify in the future and seriously damage our soil and water resources. Therefore, it is critical to evaluate how well conservation practices protect soil and water resources from the impact of climate change. A winter rye cover crop grown between harvest and planting in corn and soybean rotations can maintain soil health and reduce losses of nutrients and sediments to water sources. These benefits may reduce the negative impacts of the higher temperatures and more variable rainfall patterns that are predicted to occur in the Midwest with climate change. We used an agricultural systems model to quantify how winter rye cover crops impact crop production and environmental outcomes with different future climate change scenarios. We found that over a 45 year simulation period that a winter rye cover crop reduced the loss of soil carbon, erosion, and nitrous oxide emissions, but was unable to completely offset predicted future corn and soybean yield declines. This research shows that cover crops can play an important role in protecting soil and water resources in the future, but do not completely mitigate the effects of climate change. Currently less than 2% of the croplands in the Midwest are planted with cover crops so this research indicates that cover crop use needs to be greatly expanded to help protect soil and water resources from climate change. The impact of this research is that it can help to guide government support for farmer adoption of cover crops and further research to improve cover crop effectiveness.

Technical Abstract: It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize-soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to quantify how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We first tested APSIM with data from a long-term maize-soybean rotation with and without winter rye cover crop field site. Our modeling work predicted that the winter rye cover crop has a neutral effect on maize and soybean yields over the 45 year simulation period but increases in minimum and maximum temperatures were associated with reduced yields of 1.6%-2.7% by decade. Soil carbon decreased in both the cover crop and no cover crop simulations, although the cover crop is able to significantly offset (3% less loss over 45 years) this decline compared to the no cover crop simulation. Our predictions showed that the cover crop led to an 11-29% reduction in erosion and up to a 34% decrease in nitrous oxide emissions (N2O). However, the cover crop is unable to offset future predicted yield declines and does not increase the overall carbon balance relative to current soil conditions.