22 Follow us on Twitter @BetterFarmingON Better Farming | April 2024 Carbon Sequestration look like, and then they use planned grazing to achieve that and meet the needs of livestock. It is important to plan, monitor, control and replan as the needs of the land and cattle evolve. They have started working with the Food Water Wellness Foundation in Alberta to measure the carbon in their soil to compare to other management styles and also create baseline measurements of soil carbon in the Prairies. As his properties are resampled over time, Cross believes improving sampling systems will offer producers more opportunities to get paid for the improvements they make to carbon sequestration. “If you can keep sampling and the carbon is still there, and you can sample lots of acres, this whole process is now a lot more robust, repeatable, and affordable,” says Cross. Another way that a7 Ranche has measured improvements to the soil is by calculating animal grazing days per acre. The work that the family has put into improved soil management has yielded increases in productivity. “I took over the ranch in ’86. At that time, the ranch was at about 30 animal days per acre. After using the planned grazing strategy, we are getting up to 90 to 120 animal days per acre,” says Cross. With multiple categories of soil carbon and different ways to sequester them, research is occurring across Canada to improve and monitor carbon sequestration in agricultural soils. Innovative approaches Traditionally, approaches to increasing soil carbon have focused on management of crops, forages, and pastures. Chiang’s and Santos’s research at the U of G is taking another approach to improving carbon sequestration in Ontario. Their enhanced rock weathering project uses minerals applied to crop land, similarly to other minerals or hard fertilizers, to increase the carbon removed from the atmosphere. “Rock weathering is a natural process and is one of the ways that the planet has been balancing carbon dioxide throughout geological time,” says Chiang. “It’s a very slow reaction, so it takes a very long time. That’s why we call our process enhanced. We would like to advance the rate of this process because human activity has been too busy releasing carbon.” Wollastonite is a mineral that is currently mined in Southern Ontario. In their research, Chiang and Santos have found that it is ideal for the enhanced rock weathering process. “Basically, we spread these minerals in the field and then the minerals dissolve because of plant activity and the interaction with soil and microbe. This interaction generates acid and dissolves the rock,” explains Chiang. “When the rock is dissolved, you have calcium and magnesium, and when they react with carbon dioxide, they capture it as a solid, rather than a gas.” Santos adds that rainwater also contributes to this process. “Once the mineral is dissolved in water it can do a few things. It can precipitate into inorganic solids in the soil or go down through the soil to an aquifer,” says Santos. He says the overall goal is to use the mineral to essentially develop new soil that can store carbon. Chiang says they have begun discussions with companies and farmers to determine how this could become available in the industry. Improved grazing management can improve soil health. Emily Croft photo
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