Application of crushed rocks to sequester CO₂ and improve soil fertility (CL24001)

Summary: 

This project is exploring how applying rock dust to soils could help reduce carbon dioxide (CO₂) in the atmosphere while improving soil health and crop productivity. 

Known as enhanced rock weathering (ERW), this emerging method involves spreading finely crushed rocks (like basalt) on soils. When the rock silicate materials react with dissolved CO₂ in the soil, it forms bicarbonate ions (HCO3-) that sequester atmospheric CO2 in soil over thousands of years.  

Beyond its carbon capturing potential, rock dust has been found to naturally release micronutrients such as potassium, magnesium, and calcium. These nutrients can support healthier soils and may lead to improved plant growth and higher yields. Other co-benefits of ERW also include soil restoration and protection against pests and diseases, offering multiple benefits to growers.  

The project will focus on understanding the types of rock dust available across Australia and assess their ability to sequester carbon and improve soil health and crop yield. Trials will evaluate how effective different rock types are across various soil types and climate zones, as well as how quickly they break down and release nutrients. Researchers will also develop a methodology to verify how much carbon dioxide is actually stored in the soil through ERW.  

To support decision-making for growers and industry, the project will produce a national suitability map showing where ERW is most likely to be effective. It will also explore the broader environmental, social and economic implications of adopting this technology on a larger scale.