Abstract:

Long praised for the ability to fix erosion, fix atmospheric nitrogen, and improve soil health, cover crops might be able to play an important role in reducing the effects of climate change on agriculture.

According to a Penn State’s Jason Kaye, professor of soil biogeochemistry in the College of Agricultural Sciences, cover crops have the climate-change mitigation potential, comparable to other practices like no-till. Kaye contends that cover cropping can be an adaptive management tool to maintain yields and minimize nitrogen losses as the climate warms.

Collaborating with Miguel Quemada in the Department of Agriculture Production at the Technical University of Madrid in Spain, Kaye reviewed cover-cropping initiatives in Pennsylvania and central Spain. He said that lessons learned from cover cropping in those contrasting regions show that the strategy has merit in a warming world.

The researchers concluded that cover-crop effects on greenhouse-gas fluxes typically mitigate warming by 100-150 grams of carbon per square meter per year, which is comparable to, and perhaps higher than, mitigation from transitioning to no-till. The key ways that cover crops mitigate climate change from greenhouse-gas fluxes are by increasing soil carbon sequestration and reducing fertilizer use after legume cover crops.

Despite the benefits, Kaye is not necessarily advocating that cover crops be planted primarily for the purposes of climate-change mitigation or adaptation. Instead, he thinks the most important conclusion from his analysis is that there appear to be few compromises between traditional benefits of cover cropping and the benefits for climate change.