– What can farmers do to help slow climate change that will actually work? This question underlies our research. To date, there is no clarity on what regenerative practices are most effective at increasing carbon storage in soil, says Kimberly Nicholas, associate professor at Lund University Centre for Sustainability Studies, and one of the authors of the study.

She and research colleague, Jessica Villat, researcher at the Harvard Extension School, Harvard University, have conducted a comprehensive literature study of seven regenerative farming practices across the globe. These have previously been highlighted as beneficial for carbon storage, since they make the soil healthier and more able to sequester carbon. They used 345 measures to quantify the carbon sequestration of these practices, to analyse their effectiveness. Of these, almost 3/4 of the measures were reported for annual croplands, and over 2/3 were for the impact of just one practice, non-chemical fertilizer. 

Seven ways to increase carbon storage in soil

1. Animal integration: Using animals on cropland, like sheep grazing in vineyards
2. Non-chemical pest management: Eliminating chemical inputs like herbicides & pesticides
3. Cover crop: Growing vegetation amidst the harvested crop, like in vineyard alleys and under the vines 
4. Legume cover crop: Using a nitrogen-fixing cover crop instead of adding fertilizer 
5. No-tillage: Eliminating soil plowing, or reduced and rotational tillage with shallow organic amendments 
6. Agroforestry: Integrating trees and shrubs with the main crop 
7. Non-chemical fertilizer: Replacing synthetic with organic fertilizers

The study also shows that combining two practices, rather than applying them individually (for example, cover crops plus no-tillage) may further enhance carbon storage. 

– Based on our analysis, we find that all seven practices can effectively increase soil carbon sequestration. Farmers can choose to use some, or a combination of these practices, in their agriculture, balancing ease of implementation and carbon sequestration effectiveness, says Kimberly Nicholas. 

– Furthermore, these practices also provide other benefits, and there is good reason to expand and support farming practices that are good for soil, health, and climate.

Practices suitable to woody perennials

The identified practices can be implemented globally, depending on climate suitability. Yet, they seem to be especially suitable to woody perennials, suggesting that they will work especially well in wine growing regions, notes Kimberly Nicholas.

– This is promising both for the future of the wine industry, and for the future of our planet, says Kimberly Nicholas.

More research needed

Kimberly Nicholas and Jessica Villat conclude that more research is needed on carbon sequestration in perennial systems, and on the practices that only report a handful of cases worldwide.

– While our sample sizes are too low to make final conclusions, we can still show that these practices can help sequester carbon and thus fight climate change.