What is regenerative agriculture (RA) and why is there interest in this approach? RA incorporates farming and grazing practices that improve the land while increasing soil fertility and organic matter content rather than depleting natural soil resources. Healthier soil means more nutrient-dense food. It improves soil biodiversity.
Some practices used in RA include no-till agriculture, cover crops, crop rotation and conservation tillage. Another potential advantage is that is has great potential to capture and sequester carbon (https://regenerationinternational.org/why-regenerative-agriculture/).
The Rodale Institute reports that “we can actually reverse climate change by increasing soil carbon stocks.” This is in addition to RA restoring topsoil, which under current practices will be almost gone in 60 years worldwide (https://rodaleinstitute.org/blog/regenerative-ag-could-sequester-100-percent-of-annual-carbon-emissions/).
The World Resources Institute writes, “The world’s soils store several times the amount of carbon as the atmosphere, acting as a natural ‘carbon sink.’ But globally, soil carbon stocks have been declining as a result of factors such as the conversion of native landscapes to croplands and overgrazing. One goal of regenerative practices is to use some of the carbon that plants have absorbed from the atmosphere to help restore soil carbon.”
Proponents of RA are firm believers in its capacity to reverse climate change through carbon storage. Others state that for carbon to remain in the soil long-term, it must be converted into organic matter by microbes which “requires around one ton of nitrogen for every 12 tons of carbon sequestered (in addition to the nitrogen used and removed by the growth (of plants))” (https://www.wri.org/blog/2020/05/regenerative-agriculture-climate-change).
This nitrogen requirement is an important limitation to successfully sequestering carbon in soil. It is problematic to add more nitrogen in the form of fertilizer since it has the potential to degrade water quality or be off-gassed as nitrous oxide, a greenhouse gas.
Additionally, more research is needed on how carbon actually sequesters in soil. It is challenging to accurately account for soil carbon levels, which are site specific, may be reduced if a soil is plowed after a few years or may be relocated from another area increasing carbon storage in the new location while decreasing it on the original site.
RA has enormous potential in climate change mitigation, but numerous scientific and practical challenges must be addressed (World Resource Institute). Current tilling practices release carbon from the soil. Pesticide application can adversely impact the soil microorganisms essential to carbon sequestration processes.
Healthy soil is a finite resource that must be conserved. Regenerative Agriculture methods hold great promise.