Cover crops support the climate change mitigation potential of agroecosystems

RESEARCH ARTICLE Cover crops support the climate change mitigation potential of agroecosystems Jonas Scho¨ n1, Norman Gentsch2, Peter BreunigID1* 1 Weihenstephan-Triesdorf University of Applied Sciences, Triesdorf, Germany, 2 Institute of Earth System Science, Section Soil Science, Leibniz Universita¨t Hannover, Hannover, Germany * peter.breunig@hswt.de Abstract Cover crops have the potential to mitigate climate change by reducing negative impacts of agriculture on ecosystems. This study is first to quantify the net climate change mitigation impact of cover crops including land-use effects. A systematic literature and data review was conducted to identify major drivers for climate benefits and costs of cover crops in maize (Zea maize L.) production systems. The results indicate that cover crops lead to a net climate change mitigation impact (NCCMI) of 3.30 Mg CO2e ha-1 a-1. We created four sce- narios with different impact weights of the drivers and all of them showing a positive NCCMI. Carbon land benefit, the carbon opportunity costs based on maize yield gains following cover crops, is the major contributor to the NCCMI (34.5% of all benefits). Carbon seques- tration is the second largest contributor (33.8%). The climate costs of cover crops are mainly dominated by emissions from their seed production and foregone benefits due to land use for cover crops seeds. However, these two costs account for only 15.8% of the benefits. Extrapolating these results, planting cover crops before all maize acreage in the EU results

in a climate change mitigation of 49.80 million Mg CO2e a-1, which is equivalent to 13.0% of the EU’s agricultural emissions. This study highlights the importance of incorporating cover crops into sustainable cropping systems to minimize the agricultural impact to climate change. 1. Introduction Mitigating climate change through measures in agriculture and food systems is essential for achieving the 1.50˚ and 2.00˚C climate change targets of the Paris Agreement [1]. Worldwide, agriculture and food production systems are responsible for about one-third of global anthro- pogenic greenhouse gas (GHG) emissions, of which 40.0% are caused by agricultural produc- tion and 32.0% by land use and land use change [2]. However, agricultural systems also offer opportunities for climate change mitigation. Agroecosystems have significant potential to reduce global net emissions [3] and could even act as a net carbon sink [4]. To achieve these emission reduction and carbon sequestration opportunities, a transformation of agricultural systems is required. An essential component of climate-smart agricultural systems is planting cover crops. Cover crops are plants or plant mixtures that are not harvested for revenue, but PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0302139 May 8, 2024 1 / 20 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Scho¨n J, Gentsch N, Breunig P (2024) Cover crops support the climate change mitigation potential of agroecosystems. PLoS ONE 19(5): e0302139. https://doi.org/10.1371/journal. pone.0302139

Editor: Abhay Omprakash Shirale, IISS: Indian Institute of Soil Science, INDIA Received: November 29, 2023 Accepted: March 28, 2024 Published: May 8, 2024 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0302139 Copyright: © 2024 Scho¨n et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the manuscript and its Supporting Information files. Funding: The research was funded by the German Federal Ministry of Education and Research within