Geophys. Res. Lett. http://doi.org/gd6d4v (2018)

Planting winter cover crops is a common agricultural management strategy that provides local benefits, including reduced soil erosion and improved soil quality. However, the impact of cover cropping on climate change is less well established.

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Nigel Cattlin/Alamy Stock Photo

Danica Lombardozzi of the National Center for Atmospheric Research, USA, and colleagues conduct a modelling experiment using the land and atmosphere components of the Community Earth System Model to assess the biogeophysical climate impacts of cover cropping throughout North America. Simulated cover crops are shown to potentially increase wintertime surface air temperature up to 3 °C for the northern United States and southern Canada. Leaf area and snow depth interact to impact surface albedo and latent heat flux. Consequently, wintertime warming is greatest where the winter snowpack is shallow and crops protrude above it. Although cover cropping has clear agricultural benefits and may even increase sequestration of carbon in soils, selecting appropriate varietals with less leaf cover or shorter heights to fit local conditions may be necessary to minimize winter warming.