Best Poster Presenter Award at the International Soil Science Society (Soils 2025), Penang, Malaysia. The Role of the Soil Microbiome in Carbon Sequestration and Capture in Soils Amended with Mineral Wastes (Presenter: Sam Marron).

The Role of the Soil Microbiome in Carbon Sequestration and Capture in Soils Amended with Mineral Wastes

Since the turn of the century, a new term has been increasingly used to define a new planetary epoch ‘The Anthropocene’. This denotes a global period where human activity is the primary driver behind contemporary environmental change. The most prominent markers of the Anthropocene include climate change and its consequences, unprecedented biodiversity loss, and the changing chemical compositions of soils, oceans and the atmosphere. Unprecedented impacts from global temperature rise are already being felt across the globe with increased droughts and stronger storms. The IPCC predicts overshooting 1.5 °C, even for a short period, will lead to much more severe, and irreversible impacts from local species extinction to loss of human lives. To remain within 1.5 °C society must not only shift to a net-zero energy system but also implement carbon removal methods, such as carbon sequestration through soils creating new carbon sinks in the process. Biogeochemical cycles, including the carbon cycle, are primarily driven by microbial communities. Carbon sequestration is a part of this cycle that is also mediated by many microorganisms that induce carbonate precipitation through a range of metabolic processes including ureolysis, sulphate reduction, or photosynthesis. A new enhanced form of carbon sequestration has been proposed in recent years, a nature-based carbon capture technique called enhanced weathering. It is a process that involves spreading finely ground silicate rock upon the land to accelerate natural weathering, therefore, increasing the speed of chemical interactions between the rock, water, and air. Enhanced weathering has the potential, in the UK, to capture 430 Gt of CO2. Not only does it have the potential to offset huge swathes of carbon emissions, it also improves soil health and fertility, can increase crop yield and nutrient uptake, and has the potential to be a co-benefit in counteracting ocean acidification. Despite this, there is a limited understanding of the full diversity of carbonate-precipitating microbes within the soil microbiome and the microbial interactions and processes behind inorganic carbon capture within soils are poorly defined. The goal of this research is to understand the microbial diversity and composition of mineral-waste amended soils, determine crucial functional genes and metabolic pathways through DNA-based molecular methods to elucidate the role the microbiome plays in carbonate-precipitation in soils. Knowledge provided from this project will contribute to a greater understanding of soil's role in carbon sequestration, better land management practices, establishing a circular economy through the application of mineral wastes primarily from brownfield sites, and reduction in the environmental carbon cost of low and poor nutrient soils.