What does all this have to do with ducks? Breeders are currently focused on developing corn that is drought- and cold-tolerant and matures earlier than current varieties. Greater tolerance to drought would expand the geographic range of corn westward, and increased cold tolerance and earlier maturation moves the range north. Almost inevitably, this expansion is likely to occur at the expense of existing grasslands and wetlands. The intensive agricultural techniques required for corn production have already transformed the Prairie Pothole Region of Iowa and Minnesota from a rich waterfowl production area to cornfields stretching to the horizon. The bottom line is that when the core of the duck factory becomes a corn factory, nesting habitat and wetlands disappear, and ducks lose.
Switchgrass for ethanol and ducks?
Switchgrass has been used for decades to create habitat for nesting ducks. However, it is typically used as one of several species in a mix of grasses, and after establishment, these plantings are usually not harvested for hay. Currently, the enzyme systems used to digest cellulose can process only a single plant species at a time, so stands composed entirely of switchgrass are expected to be planted. Will ducks nest in pure stands of switchgrass, and will the switchgrass stubble that remains from the fall harvest be attractive to them as nesting cover?
To resolve these questions, Ducks Unlimited biologists are planning a collaborative study with Ceres Inc., the leading developer of biomass crops. Under contract with DU, farmers will plant switchgrass fields and manage them as they would for biomass production. At harvest time, farmers will cut the grass at two heights—6 inches and 12 inches—and researchers will then track duck nesting density and success. Scientists will also evaluate the effect on other birds as well as on “eco-assets” like the amount of organic carbon stored in the soil. Such assets are becoming marketable as a way to combat global warming and would provide additional income to the farmer.
If Congress provides funds for this study, DU and Ceres will be positioned to recommend management practices that not only enhance the production of switchgrass for ethanol but also benefit ducks, other birds, and the environment.
Dr. Jim Ringelman is director of conservation programs at DU's Great Plains Office.