Farmers routinely incorporate calcium into their soil management practices for various reasons, such as pH regulation and soil structure enhancement, with the ultimate goal of boosting crop yields. Now, researchers from Cornell University and Purdue University, utilizing the Canadian Light Source (CLS) at the University of Saskatchewan, have unveiled a previously unknown mechanism triggered by calcium when introduced into the soil. This discovery holds the potential for more targeted and strategic applications of the mineral in agriculture, offering insights into microbial interactions and organic matter stabilization.
The study, led by Itamar Shabtai, an assistant scientist at the Connecticut Agricultural Experiment Station, harnessed the capabilities of the CLS to delve into the impact of calcium on soil microbial communities and organic matter processing. While the influence of calcium on the stabilization of organic matter was established, the specific effects on microbial communities and their functions remained a mystery.
Shabtai explains, “We showed that by adding calcium to soil, we changed the community of microbes in the soil and the way they process organic matter.” This alteration resulted in a more efficient processing of organic matter, leading to increased carbon retention in the soil and reduced carbon loss into the atmosphere as CO2.
Carbon, constituting around half of the organic matter in soil, is a pivotal component influencing various soil properties. Healthy soils with higher carbon content exhibit improved water retention during drought conditions, enhanced nutrient delivery to plants, and increased resistance to erosion. Shabtai emphasizes the global significance of soil carbon, stating that soils collectively hold more carbon than both plants and the atmosphere combined. Retaining this carbon has the potential to mitigate the increase in atmospheric CO2 and address climate change.
The researchers utilized the SGM beamline at the CLS to measure plant matter decomposition following the addition of calcium. Additionally, the Mid-IR beamline facilitated the identification and quantification of stabilized carbon in the soil, providing crucial data otherwise unattainable. Shabtai underscores the unique capabilities of the CLS in enabling this groundbreaking research.
The implications of this study extend to agricultural practices, offering farmers a new tool to enhance the organic matter content in their soils. Shabtai envisions practical applications, stating, “Now that we have a better understanding of how calcium can impact how microbes improve soil carbon, we can perhaps use soil amendments that contain calcium and are already being used by farmers—such as lime and gypsum—in a way that can benefit soil organic matter.” This newfound insight into the intricate interplay between calcium, microbes, and soil carbon opens doors to more sustainable and informed soil management strategies, with potential implications for addressing climate change.