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Dr Marc Redmile-Gordon leads the research in soil biology and ecosystem nutrient cycling to highlight sustainable ways gardeners can improve their soil and deliver climate mitigations
As an environmental scientist, I help deliver RHS sustainability targets through research and review.
My research aims are:
I am investigating the role of microbial EPS in maintaining soil health and climate with international collaborators. The laboratories at RHS Hilltop are now equipped to extract and investigate these sticky microbial substances. This lab-work helps us to understand i) how soil microbes underpin good soil health and plant productivity; and ii) how soil microbes affect soil carbon storage.
EPS functions like a glue or ‘mortar’, it is vital for holding small soil particles together (silts and clays). A combination of fungal hyphae and EPS maintains soil structural stability, keeping the tiny channels and pores of a healthy soil ‘open for business’ – enabling transport of water, air and nutrients. We have found that improvements in soil structure follow increases in EPS.
Soil health: This forms the basis for good-looking plants, wholesome fruit and veg, and biodiversity. At the heart of good soil health is biodiverse food web, releasing nutrients to plants, which in return, provide carbon to the soil. Healthy plants and soil support one another.
Most soil biology is invisible to the naked eye. Microscopic organisms form an intimate relationship with plant roots. The plants invest carbon (taken from the atmosphere) as sugars into the soil. In return, microbes make useful substances (EPS) from these sugars. EPS maintain a soil’s structural stability, which brings benefits to climate, soil biology, and plant-health.
Climate-positive gardening: We can only be confident we are working to combat climate change if we progressively reduce our dependency on fossil fuels. Home-grown carbon has immense value over imported carbon. Once ‘fossil-free’ methods of gardening are established, a well-structured soil can help to mitigate climate change by reducing emissions of greenhouse gasses. Improving soil health also improves a soil’s resilience against drought and flood – bringing additional plant-health benefits. Improved plant growth enables the temporary removal of more CO2 from the atmosphere. This carbon can then be stored in the local soil for decades.
Climate-positive soil management requires attention to the seasons. Soils rich in organic matter tend to lose nitrogen in wet conditions, with some of this becoming N2O (a potent greenhouse gas). We are investigating treatments and approaches to prevent this.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.