2018/01/31 by Bruno Mary, Ceschia, Eric, Morgan Ferlicoq +10
Agricultural and Biological Sciences · Environmental Science · #Agroforestry and silvopastoral systems #Soil and Land Suitability Analysis #Sustainable Agricultural Systems Analysis
paper · doi:10.15454/1.517402718167511e12
Cover crops have long been used for their ability to reduce erosion, reduce nitrate leaching and improve soil properties in general. Since the application of the European directive on nitrate in vulnerable zones, the use of cover crops has increased and, in a climate change context, there is a growing interest for their ability to increase soil organic carbon content. This practice is considered as fundamental in the “4 per 1000” initiative that was launched after the COP21. In this paper, we evaluate the potential of cover crops to increase carbon storage in agricultural soils but also the positive and negative effects of cover crops on climate. We consider both the biogeochemical effects (Carbon storage in soil, N2O emissions, emissions from field operations) and biophysical effects (changes in albedo and energy balance at soil surface) that modify the radiative forcing (net climatic effect) of plots where cover crops are grown in comparison with bare fallow plots. This innovative integrated approach is based on recent literature, ongoing research and meta-analysis. The synthesis of these studies shows that in most cases there is a synergy between the biogeochemical cooling effects and the biophysical ones. A more systematic accounting of all those processes could increase the climate mitigation efficiency of cover crops.