BIOLOGICAL PATHWAYS TO
CARBON RICH SOILS Webinar with Dr Christine Jones Dr Christine Jones will be well known to anyone that has been studying soil health or regenerative farming as her reputation spreads far and wide. I first saw her speak at Groundswell in 2017 and have spent many hours watching YouTube videos ever since. Christine is renowned for speaking about the Liquid Carbon Pathway which explains how carbon is a dynamic product in the soil.
Carbon is a hot topic in agriculture across the world at the moment, mainly as a commodity that could be sold to buyers that need to offset their corporate carbon footprint. I believe that this is missing a fundamental piece of the jigsaw which is that Carbon is the basic currency in the soil. It is traded for nutrients and other essential resources by plants and microbes, so the loss of carbon in our soils means that they simply don’t function as well as they should. By paying attention to carbon management we can improve function, reduce inputs, produce food that is better for consumers and crucially be more profitable. In addition it is clear that carbon plays a key role in providing wider Ecosystem Services, including climate resilience. Dr Jones explained how photosynthesis was the real foundation for all life, as it uses free resources to drive energy into the system. Green plants use light, CO2 and water to create carbohydrates that are exuded into
Rhizosheaths on oats
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Root exudates cradled by fungal hyphae mag x 150 (14July20)
the soil through plant roots. Here the microbes in the rhizosphere exchange the carbon for other products that the plant needs, which in turn facilitates
more photosynthesis and the cycle continues. In a monoculture, the variety of microbes in the rhizosphere is quite limited, but in a multi-species situation there is an increase in both number and diversity of the microbial population. This diversity can be increased by the improved photosynthetic efficiency of a diverse sward, as the variety of leaf architecture means that more sunlight is intercepted. More light interception delivers greater photosynthetic capacity, driving more exudates into the soil that feed higher populations of microbes. So why are microbes important? I can remember being taught that it was the roots that took up the nutrients, but in fact it is the microbes that facilitate this. They are far more efficient and numerous, as long as we look after them properly. Microbes have a huge array of different functions and services that they can provide, so diversity of the population leads to a wider variety
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