Figs 2 and 3, Table 2 and S1 and S2 Files are incorrect. The results of the studies Engedal et al. 2023 and Notoris et al. 2019 should have not been included in the quantification carbon sequestration effects of cover crops. Please see the correct Figs 2 and 3, Table 2 and S1 and S2 Files here.

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Fig 2. Forest plot of included literature on carbon sequestration effects.

https://doi.org/10.1371/journal.pone.0319516.g001

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Fig 3. Sankey plots describing gains and losses of different scenarios for the NCCMI.

https://doi.org/10.1371/journal.pone.0319516.g002

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Table 2. Calculation of the net climate change mitigation impact of cover crops during an annual cropping cycle.

https://doi.org/10.1371/journal.pone.0319516.t001

In the Abstract section, there is an error in the fourth and tenth sentences. The correct fourth sentence is: The results indicate that cover crops lead to a net climate change mitigation impact (NCCMI) of 3.27 Mg CO₂e ha^-1 a^-1. The correct tenth sentence is: Extrapolating these results, planting cover crops before all maize acreage in the EU results in a climate change mitigation of 49.37 million Mg CO₂e a^-1, which is equivalent to 12.9% of the EU’s agricultural emissions.

In the Methods section, there is an error in the third sentence of the fourth paragraph. The correct sentence is: Only 41 articles met these criteria and were finally included in the review. In addition, we used 31 publications from Google Scholar and data from 26 other Internet sources that were selected based on the above criteria.

In the Carbon sequestration subsection of Results, there is an error in the third and eighth sentences of the first paragraph. The correct third sentence is: In addition, 24 studies that were not included in the above-mentioned meta-analyses were also included in our calculations. The correct eighth sentence is: The weighted mean of all studies investigated shows an average sequestration of 1.43 Mg CO₂e ha^-1 a^-1 (95% CI, 0.89, 1.97).

In Nitrogen fixation subsection of Results, there is an error in the fourth, fifth and eighth sentences of the paragraph. The fourth and fifth sentence should have been a single sentence and written as: For example, winter vetch, which fixes 85.00 kg N ha^-1 as single species and 113.00 kg N ha^-1 in a mixture with winter rye [13]. The correct eighth sentence is: The summarized literature resulted in a weighted mean of 50.15 kg N ha-1 (95% CI, 29.72, 70.58) that can be contributed by legumes from nitrogen fixation.

The paragraph in Net climate change mitigation impact (NCCMI) of cover crops subsection of Results is incorrect. The correct paragraph is: We calculate the summary of all climate benefits from cover crops as 4.20 Mg CO₂e ha^-1 a^-1 (95%CI, 1.26, 7.42) and all climate costs from cover crops as 0.93 Mg CO₂-eq ha^-1 a^-1 (95% CI 0.51, 1.34). The NCCMI of cover crops was calculated as 3.27 Mg CO₂e ha^-1 a^-1 (Table 3). The NCCMI was then extrapolated to the maize harvest area for all EU-27 countries. Here, we assume a scenario in which cover crops are grown before maize on all of the EU-27’s harvested maize areas, which is 15,092 x 10⁶ ha, on average [23]. Based on this calculation, planting cover crops before maize in the EU-27 results in a climate change mitigation potential of 49.37 million Mg CO₂e a^-1. This is equivalent to 12.9% of the EU-27’s agricultural GHG emissions [51].

In Review of results subsection of Discussion, there is an error in the second and 14^th sentences. The correct second sentence is: This resulted in a positive NCCMI of 3.27 Mg CO₂e ha^-1 a^-1 that can be achieved if cover crops were incorporated in crop rotations of maize production. The correct 14^th sentence is: Closer nutrient cycling and reduction of leaching losses resulted in another 23.8% of cover crops’ climate benefits, including nitrogen fixation of legume cover crops.

In the Conclusion and policy recommendations subsection of Discussion, there is an error in the third sentence of the first paragraph. The correct sentence is: If all maize cropping acreage in the EU-27 were to include cover crops, GHG emissions from EU-27 agriculture could be reduced by 12.9%.

Notoris et al. was incorrectly included as reference 27. As a result, all subsequent references are misnumbered. References 28–66 should be references 27–65.