By Matt O'Neal and Katherine Kral-O'Brien
A recently published summary of over 15 years' worth of research reveals farmers can conserve pollinators at the edges and even inside corn and soybean fields. This conservation is in the form of prairie strips planted with native, perennial flowering plants. Prairie strips offer significant food and nesting habitat for pollinators (Photo 1).
Scientists at Iowa State University and the University of Illinois explain how the abundance and diversity of wild bees respond positively to prairie strips (Toth et al. 2026). All pollinators need flowering plants, especially in Iowa, where over 70% of the land is committed to corn and soybean production, which have limited value to most pollinators. Without flowers, bees and other pollinators lack the carbohydrates and protein to fuel them. This is especially true for honey bees (Photo 2), which convert nectar from many plants into the honey harvested by beekeepers. Prairie strips contain dozens of flowering species that provide flowers throughout the growing season. These plants provide nectar and pollen especially after soybeans and clover stop flowering. Landowners can enroll in the USDA prairie strip conservation practice (CP-43) to reduce soil erosion, capture excess nutrients, and provide wildlife habitat. Participation in this Conservation Reserve Program (CRP) helps cover some of the costs associated with establishing and maintaining prairie strips.
What does it mean for farmers?
The prairie strip practice allows farmers to continue producing corn and soybeans while addressing the needs of pollinators. The impact of pesticides used during the production of crops adjacent to the prairie strips was studied during the development of this conservation practice. Farmers can limit the impact of insecticides on pollinators by following the product label and using integrated pest management practices. When farmers apply pesticides while limiting drift, the plants and many animals inside prairie strips thrive. Although the research team found insecticides in prairie strips, the concentrations of insecticides, like neonicotinoids, were well below what is considered acutely toxic to bees and butterflies. Honey bees kept at farms with prairie strips did not experience an increase in pesticide exposure, and honey bee colonies kept at farms with prairie strips produced more honey than at farms without prairie strips (Photo 3). Neonicotinoids were found in flowering plants and milkweed (the monarch butterflies' host plant) at concentrations below what would cause mortality to 10% of the population (LC10 values). Prairie strips supported higher densities of monarchs compared to grassy strips of vegetation. The authors concluded that prairie strips offer vital resources for pollinators without increasing exposure to pesticides.
Source : iastate.edu