Jennifer Blesh
Associate Professor Jennifer Blesh at Campus Farm. Photo by Dave Brenner.

Meet the Future of Sustainable Food Systems: A Focus on Soil Health and Crop Diversity

By Nayiri Mullinix

Although the global population has more than tripled since 1950, studies show that modern intensive agriculture, which largely ignores ecological practices and focuses on a small number of high-yielding commodity crops reliant on chemical fertilizers and pesticides, did not grow out of necessity, but rather a drive for profits.

These methods have spawned environmental consequences and problems throughout food systems, with a major concern being soil health. So much so, in 2022, the Food and Agriculture Organization of the United Nations warned that, unless current pratices are changed, 90% of topsoils will be degraded by 2050. Agroecologist Jennifer Blesh is an associate professor who came to the University of Michigan School for Environment and Sustainability (SEAS) in 2014 as part of a Sustainable Food Systems cluster hire—intended to encourage collaboration across U-M schools and colleges by hiring faculty with similar research interests—which included Meha Jain, also in SEAS, Andy Jones in the School of Public Health, Lesli Hoey in the Taubman College of Architecture and Urban Planning, and Regina Baucom in Ecology and Evolutionary Biology in the College of Literature, Science and the Arts (LSA).

“Healthy soil is a living ecosystem that has an active biological community and is packed with carbon and nutrients. Healthy soil gives us life. But today, due to low crop diversity and excessive use of chemical inputs and tillage, many agricultural systems have not only lost vast amounts of soil, but the remaining soil is degraded,” says Blesh. 

Blesh explains that soil degradation threatens our ecosystems and climate, and thus the future of food access. To be sustainable, ecological processes will need to be managed using species diversity to sustain production and support important functions including restoring soil health.

“These practices aren’t new. They were developed by Indigenous communities and groups of farmers around the world, but expecting farmers to flip a switch and go from growing acres of corn using pesticides and fertilizers to diversifying their output isn’t realistic,” says Blesh.

“Time, policy support and funding will be needed, but making the shift is essential to ensuring the stability of our food systems.”

Researchers and students in Blesh’s lab support farms in incorporating methods that boost soil health. One method is cover cropping—planting grasses, legumes or forbs such as clover or ryegrass to enrich and protect soil.

Green Things Farm Collective in Ann Arbor, founded by Nate (BA ’08) and Jill Lada (BS ’10), both graduates of the Program in the Environment (PitE), is one of 10 farms Blesh’s team partnered with on a study to identify factors that cause different cover crop outcomes.

“The Ladas manage a highly diversified farming system. They worked with our team on research where we tested how different types and levels of cover crop diversity relate to essential benefits from cover crops, like nitrogen supply, nutrient retention and weed control,” says Blesh.

Food systems should be environmentally sound and provide healthy foods for all, considering all outcomes, not just yield.”

Nate Lada says that cover cropping protects and enriches the soil. 

“Cover crops give soil nutrients and structure with roots that protect it from heavy rain, erosion and slow weed growth,” says Lada. “Then, in late spring, before summer planting, we use occultation (or tarping) to trap heat and kill off the crop, which produces straw, providing more soil-enriching biomass and organic matter.”

Blesh adds that soil enrichment also helps to mitigate climate change.

“Through photosynthesis, cover crops take atmospheric carbon dioxide and turn it into organic carbon in plant biomass. A portion of that carbon is retained and potentially sequestered long-term in the soil.” This results in using fewer synthetic fertilizers produced with fossil fuels, which reduces greenhouse gas emissions. 

Etienne Sutton (BS ’18, PhD ’24), became interested in the benefits of cover crops as a PitE student taking the Foundations of Sustainable Food Systems class taught by Blesh and her cluster hire colleagues Jones and Hoey.

“I was introduced to cover crops in this class as a way to increase biodiversity and ecosystem services on farms, and was immediately intrigued,” says Sutton.

So much so, that she based her dissertation research on cover crops, designing a citizen science project that reached over 100 farms across the Midwest. Using real-time data, Sutton demonstrated that cover crop performance was highly variable and identified strategies for maximizing benefits.

Sunflowers growing at Green Things Farm
Brian Lillie

Although Sutton’s work focused on agricultural ecology and cover crops, Blesh encouraged her to tackle research questions in an interdisciplinary and holistic way.

“Food systems are about much more than production; there’s also the people who are making decisions about and interacting with the land, influencing policy, the list goes on,” says Sutton.

Blesh adds, “We’re at an inflection point where we can’t continue business as usual. Throughout the food chain— from farmers and workers exposed to toxic chemicals to meatpackers and restaurant workers earning low wages—we have equity problems. Food systems should be environmentally sound and provide healthy foods for all, considering all outcomes, not just yield.”

Though it may seem daunting, Blesh says that producing a wide range of crops that support soil and ecosystem health as well as human health and well-being is the key to a sound future for food systems.

“Despite large barriers, a growing number of farmers, such as the Ladas, are maintaining and transitioning to diversified management systems. We can learn from these models of innovation about pathways to restoring diversity and enriching soils on farms around the world.”
 

Interested in more?

  • Read Food systems synergy from the School of Public Health, which dives deeper into the Sustainable Food Systems class taught collaboratively by Blesh, Hoey and Jones.
  • Read Hungry for change, which is focused on Hoey's work at the Taubman College of Architecture and Urban Planning. 
  • Watch a video about the Sustainable Food Systems teaching collaboration between SEAS, Public Health and Taubman.
  • Read about the recently announced $4 million grant that a group of researchers led by Blesh has received from the Michigan Department of Agriculture and Rural Development to investigate farm management practices in the Western Lake Erie Basin. The aim is to work directly with farmers to help restore soil health by using nutrients that minimize the impact of fertilizers that fuel harmful algal blooms without compromising crop yields. 

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