More than half of the world’s biodiversity lives underground in soils, including thousands of animal species that play crucial roles in maintaining soil health—the bedrock of global food security and environmental resilience. Yet current methods for assessing soil health are missing this vital component of soil life.
Assistant professor André Franco of the Paul H. O’Neill School of Public and Environmental Affairs aims to reshape how farmers, land managers, and policymakers evaluate the land, earning him a grant worth more than $737,000 from the United States Department of Agriculture’s National Institute of Food and Agriculture.
Modern soil health scorecards mostly track chemical and mineral levels, largely overlooking a vital facet of the subterranean world—the nematodes, mites, springtails, earthworms, and other invertebrate fauna that are the engines of the ecosystem. These organisms are responsible for breaking down organic matter, recycling vital nutrients, suppressing pests and pathogens, and building the soil structure necessary for plant growth. Therefore, changes in soil fauna communities can be informative for management and provide a practical indicator of soil functioning that changes detectably and quickly.
However, without understanding how these animal communities and their functions respond to different farming practices, it is difficult to determine their value for soil health assessment and whether regenerative techniques are delivering long-term benefits.
“Filling this knowledge gap is critical,” Franco said. “It isn’t just about agriculture. It’s about broader community goals such as reducing erosion, protecting our waterways, conserving biodiversity, and storing carbon.”
The project, “Integrating soil animals into the soil health framework to foster multifunctionality in regenerative agroecosystems,” includes collaborator Christine Sprunger from Michigan State University. It will conduct an extensive study across the Midwest, with research taking place at Long-Term Agroecosystem Research (LTAR) field sites in North Dakota, Nebraska, Michigan, and Ohio, comparing various crop and rangeland management strategies in real-world conditions.
In addition to field observations, the team will run controlled experiments, meticulously adjusting soil animal populations to observe their direct impact on soil performance. This dual approach will allow the researchers to develop practical soil life indicators that can be integrated into existing soil health assessment frameworks.
“Our goal is to provide agriculture professionals with more complete tools to guide investments in sustainable intensification,” Franco said. “By including soil animals in the conversation, the research will help ensure that farms remain productive while providing public benefits such as cleaner water and stronger regional economies.”