AMES, Iowa - Pollinator declines are a global concern, and agriculture sits at the center of the challenge. As farms grow more efficient and landscapes become increasingly simplified, bees, butterflies and other pollinators are losing the varied habitats they depend on. One widely promoted solution is planting native vegetation, but an important question remains: Does pollinator habitat embedded within conventional farming systems provide overall benefits if pesticides remain in the surrounding landscape?
A new report in the publication Bioscience says “yes,” based on more than a decade of field studies, laboratory analyses and landscape-scale research.
Prairie strips are diverse plantings of native grasses and flowering forbs strategically placed within corn and soybean fields to provide multiple conservation benefits. The synthesis paper evaluates what we have learned about whether these habitats provide a net benefit to pollinators despite potential pesticide exposure.
The review team was led by Professor Amy Toth, who has a joint appointment in ecology, evolution and organismal biology and plant pathology, entomology and microbiology and at Iowa State University.
‘Incredibly hopeful’ findings
“One of the most important takeaways is that even small changes in how land is managed can make a real difference,” Toth said. “It wasn’t a foregone conclusion that a small patch of prairie embedded in vast farmland could have a positive impact. But over more than a decade of research, we consistently found more abundant and diverse pollinators and stronger plant–insect interactions. That’s incredibly hopeful.”
Prairie strips are not conservation areas set aside from agriculture; they are embedded directly into some of the most intensively farmed landscapes in the world. While originally promoted for reducing soil erosion and improving water quality, researchers found that these strips also dramatically increase the availability of flowering plants in areas otherwise dominated by one or two crops.
“As scientists, we can’t assume these habitats were automatically beneficial just because they look good on paper,” said co-author Matthew O’Neal, professor of plant pathology, entomology and microbiology. “We needed to know whether the benefits actually outweigh the risks.”
The team’s synthesis shows that prairie strips support more abundant and more diverse pollinator communities than fields without them. Native bees, monarch butterflies and other insects benefit from improved forage, nesting habitat and protection from tillage.
“Honeybees and wild bees find something they’ve been missing in these landscapes: continuous, high-quality food,” O’Neal explained. “That nutrition matters more than we used to realize.”
Clear benefits
The research documents clear benefits for managed honeybees. Colonies located near prairie strips collected more pollen, grew larger and showed higher winter survival rates compared with colonies in landscapes without strips. Wild bee communities were also more diverse and abundant, forming more resilient plant–pollinator interaction networks, an indicator of long-term ecological stability.
“Prairie strips do more than just attract bees,” O’Neal said. “They’re a source of food when the rest of the landscape offers very little.”
Because prairie strips are placed within conventionally managed fields, pesticide exposure was a central concern of the study. The authors reviewed research that measured pesticide residues in plants, pollen, nectar and soils within prairie strips and evaluated those levels against established toxicity thresholds.
“Pesticides are an important concern, and we took that seriously,” Toth said. “But findings from these studies show that while pesticides can be detected in prairie strips, exposure levels are generally low and not different from what pollinators experience in other crop-adjacent habitats. Overall, we’re seeing large benefits and relatively low costs.”
Research also suggests that access to diverse, high-quality forage may help buffer pollinators from other stressors, including pesticides and pathogens. Rather than acting as ecological traps, prairie strips can function as refuges, providing forage and shelter within working agricultural landscapes.
Prairie strips offer a realistic, scalable conservation solution for farms, concludes the synthesis.
“In landscapes where very little native habitat remains, even small patches can make a meaningful difference,” O’Neal said. “Prairie strips show that conservation doesn’t have to be separate from agriculture; it can be part of it.”
Looking ahead
Looking ahead, the researchers emphasize the importance of continued study, particularly on pesticide effects across a broader range of wild pollinator species and on ways to optimize prairie strip design to ensure season-long flowering. The authors note that adoption of prairie strips continues to grow through federal conservation programs, driven by agronomic and environmental benefits that appeal to farmers and land managers.
The study points out that risks of adverse effects from pesticides could be further reduced with the adoption of low-drift application practices and the judicious use of pesticides as part of integrated pest management strategies.
“Prairie strips show how individual farmers can be powerful partners in conservation,” Toth said. “These are voluntary actions, supported by science and conservation programs, that can make a meaningful difference. That kind of collaboration gives us a model for improving both environmental outcomes and long-term agricultural sustainability.”
The BioScience article was authored by a multidisciplinary team of Iowa State researchers and alums that also included:
- Maura Hall, toxicologist, and a former PhD student from Iowa State
- John Tyndall, professor, and Steven Bradbury, emeritus professor, natural resource ecology and management, Iowa State
- Lisa Schulte Moore, Charles F. Curtiss Distinguished Professor, natural resource ecology and management, director of the Bioeconomy Institute, Iowa State
- Matthew Stephenson, data analyst, Bioeconomy Institute, Iowa State
- Professor Adam Dolezal, University of Illinois, Urbana-Champaign (UIUC), formerly a post-doctoral scientist at Iowa State
- Ashley St. Clair, formerly a PhD student at Iowa State and post-doctoral scientist at UIUC, now global regulatory ecotoxicologist, Corteva AgriScience
- Kate Borchardt, formerly a PhD student at Iowa State and now a postdoctoral researcher, University of Massachusetts, Amherst
- Edward M. Hsieh, formerly a technician at Iowa State and PhD student at UIUC, now a postdoctoral fellow, USDA Agricultural Research Service
Primary funding for the study came from the USDA National Institute of Food and Agriculture, the Iowa Soybean Association and the Foundation for Food and Agricultural Research with matching funds from Bayer Crop Science and DuPont Pioneer (now Corteva Agriscience). Funders were not involved in determining or executing the scope of work.
Listen to the Bioscience Talks interview with Toth and O’Neal, as they discuss their paper and its findings with blogger James Verdier.
Contacts
Amy Toth, Ecology, Evolution and Organismal Biology, 515-294-3121, amytoth@iastate.edu
Matthew O’Neal, Plant Pathology, Entomology and Microbiology, 515-294-8622, oneal@iastate.edu
Cindy Hicks, Seed Science Center, 515-296-5386, cghicks@iastate.edu