By William Binette
If the world were to judge soil remineralization based on what could happen, rock dust amendments might already be standard procedure for the world’s farmers. The potential to use rock dust as a carbon storage tactic for climate change mitigation is well known in the scientific community, in addition to its ability to improve agricultural yields and soil health. Benefits like these are enough to make any policymaker or farmer at least consider the use of soil amendment programs, but expectations alone are not adequate to persuade any party to go “all in.”
The University is currently carrying out several remineralization studies across multiple campuses that they hope will deliver a more holistic understanding of California soils’ carbon storage potential, and may validate the efficacy of using rock dust to combat climate change and soil degradation. Their keystone project will focus on carbon storage potential and effects on plant growth in California croplands, while other projects will explore effects of different soil components, modeling improvements and performing a thorough cost-benefit analysis. Where previous research has focused mainly on the physical and chemical processes of soil remineralization, the team at UC Davis plans to explore financial impacts, scalability, and the varying levels of benefit for different climates and soils. In short, their work aims to map out the “Yellow Brick Road” piece by piece rather than merely claiming that the road exists in the first place. With this approach, researchers can transcend the scientific community’s current understanding of rock dust to manifest a plan for realistic implementation in the future.
Given that one quarter of annual global carbon emissions come from agriculture and forestry, it’s only natural that UC Davis staff would devote resources to improving agriculture’s footprint. Under the Working Lands Innovation Center at UC Davis, teams of researchers are doing just that. The “WLIC,” as it’s known around campus, “aims to catalyze negative carbon emissions by deploying soil amendment technologies at multi-acre scales in partnership with California researchers, state agencies, industry, farmers, ranchers, tribes, and small business development.” Their work largely revolves around revolutionizing agricultural production in terms of efficiency and minimal carbon footprint; aims that the group believes can be achieved by means of basaltic rock remineralization.
The Houlton Lab, a subordinate of the WLIC, is in the midst of completing a sizable farming experiment that will compare and contrast impacts on remineralized lands with sub-divisions of land that received no rock dust, acting as the control group. The study will quantitatively illustrate what benefits California stands to gain from employing methods of remineralization, specifically those related to sequestration and crop yields. The remineralized sections of the farm, located in Los Banos, California, received about 16 tons of rock dust per acre last year. The rock dust is mostly metabasalt, a variety high in iron, zinc, and potassium that delivers elements necessary for healthy plant growth. Metabasalt supplies additional nutrients compared with artificial NPK fertilizers, and they require less fossil fuel to produce. These rocks break down by natural weathering processes that release trace elements back into the soil. There, the elements react and bond with carbon dioxide molecules to form carbonate and bicarbonate rock, removing greenhouse gases from the atmosphere and storing them in a solid form in our soils.