Beyond Carbon: Environmental Benefits of Enhanced Rock Weathering

Enhanced rock weathering (ERW) rapidly accelerates the natural rock weathering process, offering a groundbreaking solution to carbon sequestration and soil enhancement. ERW involves finely crushing reactive silicate rocks like basalt and wollastonite and spreading this powder over agricultural land, dramatically increasing surface area for carbon removal.  The increased surface area captures and permanently locks away substantial amounts of carbon quickly, with the CO2 molecules forming bicarbonate and being flushed down through the soil, waterways and ultimately oceans where it will be stored for 100,000+ years. 

Beyond permanent carbon removal, enhanced rock weathering significantly enhances soil health, boosts crop yields and supports marine ecosystems, making it a holistic environmental solution.

Basalt and Wollastonite: Enhancing Soil Health and Yields

At UNDO, we strategically utilise both basalt and wollastonite in our operations to maximise environmental and agricultural benefits. Both provide significant benefits to agricultural land, aligning with regenerative practices that sustainably enhance productivity. Agricultural land is spread with crushed silicate rock because it is rich in macro and micronutrients that nourish soils and the crops that grow from them as weathering occurs. Enhanced rock weathering practices help maintain or improve soil pH, increase pest resistance and can significantly boost crop yields, promoting healthier and more productive agricultural systems.

Understanding the chemical composition of basalt and wollastonite helps us see which essential nutrients are supplied to our partner farmers’ soils, enhancing their crop productivity. We rigorously sample our feedstock sources every 3,000 tonnes to ensure they are free of heavy metals and potentially toxic elements (PTEs), maintaining safety and quality. 

Wollastonite enriches soils with vital nutrients like calcium, silicon, magnesium and sulfur, promoting robust plant growth and resilience.  We use this chalky, soft white silicate mineral in our Canadian operations and use a commercial application rate of 5 tonnes per hectare. Silicon, in particular, boosts stress tolerance, enhances crop quality and fortifies plants against pests and diseases. Replacing traditional lime applications with wollastonite not only removes atmospheric carbon efficiently but also avoids the release of CO2 associated with lime application, a double win for the planet. Encouragingly, wollastonite can be reapplied on the same land annually, providing benefits to the environment and farmers.

Basalt, on the other hand, provides a slightly different mix of nutrients to soils. At a higher commercial application rate of 20 tonnes per hectare, basalt provides unique soil additives like phosphorous, molybdenum and selenium as the rock breaks down. Because basalt weathers much more slowly than wollastonite, its positive effects generally take longer to become apparent. However, the gradual release of nutrients over time also means that the positive effects last longer.

Academic Collaborations Advancing Soil Science

Our global academic partnerships with leading institutions and universities harness the expertise of soil scientists, geochemists and agronomists, validating our scientific methods and enhancing ERW’s credibility as an effective permanent carbon removal method.

Our strategic collaboration with Newcastle University, based at Nafferton Farm, has yielded exciting results. In March, we published a peer-reviewed paper in PLOS ONE, detailing findings from our ongoing trial. The study demonstrates that crushed basalt can significantly boost crop yields in a temperate climate and positively impact soil pH. On average, crop yields were 15% higher (ranging from 9.3% in ploughed plots to 20.5% in direct drill plots) in basalt-amended plots compared to control plots. Additionally, the soil pH in basalt-amended plots was on average 0.2 to 0.29 units higher than in control plots. 

Enhanced rock weathering (ERW) boosts soil quality by increasing essential nutrients like calcium and magnesium. This leads to better soil fertility, higher productivity and improved crop yields, supporting sustainable food production systems. Importantly, no uptake of potentially toxic elements has been observed.

David Manning, Professor of Soil Science at Newcastle University, and co-author of the paper, stated: “The results of this trial give further scientific credibility for enhanced rock weathering and greatly improve its value proposition to farmers. Newcastle University is pleased to partner with UNDO. Our joint research into the co-benefits for farmers of basalt amendment is helping to pave the way for the widespread adoption of enhanced rock weathering in the agricultural community.”

UNDO’s academic collaborations, including our partnership with Newcastle University, enhance our efforts to quantify carbon dioxide removal and contribute valuable research on the agricultural benefits of ERW for rural communities.

Biodiversity in Oceans

Enhanced rock weathering generates large quantities of bicarbonate ions, which flow through soils into waterways and eventually reach the oceans. Alkaline bicarbonates from ERW help counteract ocean acidification, enriching runoff and streams and thereby supporting diverse marine life. They prevent harmful algal blooms due to their high silica content, mitigate the adverse effects of acidification on coral reefs and fisheries, and provide essential material for small marine animals to form their shells.

A Triple Win for Carbon Removal, Soil Health and Rural Communities

Enhanced rock weathering is a win-win-win scenario. It naturally captures excess CO₂ from the atmosphere. It integrates rural communities, universities and environmental associations and brings green jobs to areas of operation. Using nutrient-rich volcanic rock, ERW also enriches agricultural land, providing significant benefits to farming practices. With climate change impacting global food production, ERW alleviates some of its worst effects. Crushed silicate rock delivers sustained alkalinity and essential nutrients stabilising soil pH and enhancing soil health over time. 

Enhanced rock weathering is a unique and scalable carbon removal solution that delivers substantial benefits to farmers, rural communities and the environment, playing a crucial role in combating climate change and enhancing agricultural sustainability.

Support High-Quality Carbon Removal

At UNDO, we utilise enhanced rock weathering (ERW) to sequester carbon and improve soil health using basalt and wollastonite. Join us in pioneering this innovative and effective solution for climate action and agricultural sustainability.

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