At the Trent University Experimental Farm, a research project is underway to harness the potential of wollastonite to combat climate change and revolutionize agriculture.
Led by School of Environment professor and Canada Research Chair Dr. Ian Power, this study aims to sequester carbon dioxide (CO2) by applying wollastonite rock, composed of calcium and magnesium silicates, to agricultural fields. Wollastonite powder has already been used as an agricultural amendment to enrich soil nutrients and promote plant growth. Professor Power’s project explores its untapped potential in helping remove carbon dioxide from the atmosphere.
“Wollastonite's fast weathering rates make it an ideal mineral for enhanced rock weathering, a CO2 removal approach that is being widely researched by academics and private companies,” says Prof. Power. “As rocks weather and interact with CO2, the resulting carbonic acid forms bicarbonate or carbonate, which can be stored in the soil or eventually draining to the ocean, providing long-term storage.”
Building a case to bring farmers on board
Ultimately, this approach holds tremendous promise for mitigating greenhouse gas emissions, while also enhancing soil health and crop production, and the Trent Experimental Farm is an ideal place to study wollastonite’s potential.
The experimental setup at the farm has the field divided into lower, middle, and upper sections, taking into account factors such as slope, which influence soil properties and the weathering and dissolution rate of wollastonite. Nine monitoring stations, including a control plot, were strategically placed across the field to collect data on soil moisture, electrical conductivity, temperature, and carbon content.
Heather Klyn-Hesselink, an M.Sc. student in the Environmental and Life Science program helping to manage the project, emphasizes the significance of accurate carbon measurement and quantification.
"We are testing some different methods of measuring the CO2 flux or the drawdown because companies are increasingly interested in the carbon credit market, and in order for them to trade carbon credits—to give out money to farmers or for anybody who tries to draw down CO2—they need to be able to measure it and quantify it."
The team is also looking to measure wollastonite’s other benefits to help build a case for farmers to spend money and time applying wollastonite. For instance, infusing the soil with wollastonite helps plants absorb silica, which fortifies their cell walls and makes them more resilient against pests, and, thus, boosts farmer crop yields.
Apart from measuring broad benefits, the team is also capturing data relevant to local farmers.
"While the overall concept of amending soil is being widely explored, it's crucial to adapt the approach to suit local conditions,” says Klyn-Hesselink. “Factors such as soil types, amendments, and management practices vary across regions, making individual experiments with different rock types necessary."
The research team also includes undergraduate researchers Chloe Lauer and Larissa Wallisch who are assisting with CO2 flux measurements, water and soil sampling, and plant monitoring. This project will continue into Summer 2024.