Farmed prairie potholes

September 29, 2020 3:11 PM
Blog Post

Prairie potholes?! What are they? Prairie potholes are low-lying, poorly drained soils that are prone to flooding. The prairie pothole region spans north central Iowa as well as Minnesota, the Dakotas, Montana, and parts of Canada. ISU Biomass is exploring how perennial crops (miscanthus) compare to annual crops (corn and soybeans) when planted in prairie potholes. The goal of the project (year 2) is to see if miscanthus is more profitable and can improve ecosystem services compared to corn and soybeans. Dr. Amy Kaleita of the ISU Agricultural & Biosystems Engineering Department has created a diagram (Figure 1) that shows what questions will be addressed.

Driving along the countryside early in the growing season gives a clear picture of why prairie pothole management needs to change. Corn and soybeans are not considered flood tolerant, so planting them in flood-prone regions often leads to loss of yield and sometimes replanting. An alternative to planting corn and soybeans in potholes would be to plant miscanthus instead. If miscanthus is found to yield better than corn and soybeans in potholes, it could be crucial in saving farmers’ resources, time, and money. Figure 2 shows corn and miscanthus plots side-by-side in a prairie pothole. The miscanthus looks healthy (the tall green crops on the right), and the corn (center of the image) looks unhealthy (very short and yellow in color) or dead.  

Figure 2. Flooded pothole at ISU's Sorenson Farm. Photo credit: Heaton Lab


This project is not only interested in end-of-season yield, but also the environmental issues associated with farmed potholes. Natural potholes offer a variety of services, including flood abatement, improved water quality, groundwater recharge, carbon sequestration, and increased biodiversity. On the other hand, farmed prairie potholes (annual vegetation) are often hotspots for nitrous oxide, a potent greenhouse gas, and can result in a loss of ecosystem services. In most cases, ISU Biomass expects miscanthus to yield higher, reduce nitrous oxide emissions, and improve ecosystem services of farmed prairie potholes compared to corn and soybeans.


Be sure to check out past and future blogs as well as ISU Biomass on Facebook, Twitter, and Instagram for updates regarding miscanthus!


Product of ISU Biomass Undergrad Team