June 29, 2023 | Nature Climate Change
Organic farming is often seen as a way to increase soil carbon storage, helping to mitigate climate change. However, this study by INRAE in France shows that converting all global cropland to organic farming could significantly reduce soil carbon inputs and stocks.
In a hypothetical scenario where all croplands switch to organic farming without using cover crops or recycling plant residues, soil carbon inputs could drop by 40%, and soil organic carbon (SOC) stocks could decline by 9% over 20 years.
In contrast, if organic farming includes practices like widespread cover cropping and better residue recycling, the reduction in soil carbon inputs would be smaller, and SOC could be preserved or even slightly increased over time. Regions vary in their response, with some experiencing higher soil carbon inputs and SOC gains, while others face declines.
The study highlights that the benefits of organic farming for soil carbon storage depend heavily on specific practices and management. Large-scale adoption without these practices may risk losing soil carbon benefits. Therefore, expanding organic farming could be more effective in mitigating climate change if it includes practices that enhance soil carbon storage.
Read more: Soil organic carbon stocks potentially at risk of decline with organic farming expansion
Fig. 3 Additional SOC stocks per ha (t C ha−1 yr−1) due to cover cropping in the optimal organic scenario compared to the normative organic scenario. The optimal organic scenario compared to the normative organic scenario.
