Without healthy soil, we damage our ability to generate clean water supplies and of course, to grow our food. And yet, soil is not currently protected under the UK’s Sustainable Development Goals and we aim to change this. The total annual cost of soil degradation in England and Wales is likely to sit at around £1.2 billion a year. Without protecting this resource for future generations we risk losing the ecosystem services which soils offer us in both the urban and agricultural environment.
We are particularly interested in urban soils and how brownfield sites can be transformed by communities into useful green spaces. Urban soils are often neglected but have the potential to help mitigate flooding, improve community health and wellbeing, increase biodiversity, and store carbon.
We are working to ensure that soil is a focus of future Government policy. The social and economic devastation (estimated at £100M so far in the 2014 UK Somerset floods alone) caused by flooding is readily apparent. But the hidden (in plain sight), arguably even bigger issue, is that the muddy floodwaters are taking even more soil organic matter (SOM or carbon) and minerals out of our soils, exacerbating the vicious circle of climate change - soil degradation - climate change - soil degradation. The recent devastating flooding in our cities could be reduced if our soils (both urban and agricultural) were capable of storing and transmitting water at the same time as retaining their shear strength so that they are not washed away. In the vacuum of legislation protecting soil, soil carbon levels have, and continue to drop and yet opportunities for policymakers and environmental specialists to work closely with the engineering sector to address these issues are being missed. We cannot preserve soils for future generations without a policy framework where soil is valued and its ecosystem services are translated into economics. This has been done for other environmental resources such as air and water but not for soil.
We have been exploring the links between minerals and carbon in soil. Minerals are known to stabilise organic carbon in sediments, affecting biogeochemical cycles and global climate, but the stabilisation mechanism is not understood. We have shown that manganese oxide, a common mineral in soils and ocean sediments, can trap organic carbon and may act as a 'mineral pump', transforming organic carbon from an unstable into a stable form. Ongoing research is focused on using this knowledge to help stabilise carbon in soils by putting carbon together with manganese and other reactive minerals back into the soil together. The food we eat and textiles we wear come from the soil and yet 30M tonnes of the resulting carbon-based wastes are not being returned to the soil to maintain soil health and SOM levels. The world’s ecosystems are reaching a tipping point, and we believe it is vital to put carbon and minerals back into the soil in order to allow soil to continue to provide essential ecosystem services. Water retention will follow, improving soil quality, mitigating flooding and potentially reducing carbon turnover to atmospheric greenhouse gases.
If you are interested in working in the following areas, please don’t hesitate to get in touch to find out more:
Dr Karen Johnson demonstrated the link between soil health and flooding with help from Hotspur Primary School. View the video here.