Soils offer an enormous potential for beneficial sequestration of atmospheric carbon dioxide as soil organic matter. Via the process of photosynthesis, growing plants capture CO2 from the air and transform it into simple sugars and more complex carbon compounds, including cellulose, lignin and, yes, oils. In the process, plants also transfer carbon compounds to the rhizosphere, that zone of intense biological activity associated with plant roots, and some of that carbon stays in the soil for a very long time.
What Galileo is reputed to have said of wine “…. light thickened to liquid,” is even more true of olive oil. Farmed well, olive oil production involves the accumulation of organic matter in the farm system, both above ground (olive trees and cover crops) and below ground (tree roots, root exudates, compost from oil production by-products, etc.). Nothing leaves the farm but the olive oil, which is derived almost entirely from the current season’s solar driven capture of carbon from the atmosphere. By optimizing our capture of solar energy as carbon, farming can help reduce the growing load of fossil-fuel driven CO2 in the atmosphere.
Applied to the management of farm and forest systems globally, this “carbon farming” approach has a significant potential to positively impact the global climate system, while at the same time increasing the resilience, fertility and productivity of our food production systems. Further, the role of soil carbon in soil water holding capacity suggests an equally important role for carbon farming in helping to mitigate the impacts of increasingly unstable rainfall patterns anticipated (and already evident) with global climate change.
- Jeff Creque, McEvoy Ranch Agroecologist