When it comes to biofuels, corn leads in terms of biomass yield. However, native grass crops used as biofuels add benefits such as fostering biodiversity and pollination.
In the current issue of the Proceedings for the National Academy of Sciences, Michigan State University researchers show that looking at the big picture allows other biofuel crops, such as native perennial grasses, to score higher as viable alternatives.
“We believe our findings have major implications for bioenergy research and policy,” says Doug Landis, an entomologist and one of the paper’s lead authors. “Biomass yield is obviously a key goal, but it appears to come at the expense of many other environmental benefits that society may desire from rural landscapes.”
Landis and a team of researchers from the Great Lakes Bioenergy Research Center compared three potential biofuel crops: corn, switchgrass, and mixes of native prairie grasses and flowering plants.
They measured the diversity of plants, pest and beneficial insects, and birds and microbes that consume methane, a greenhouse gas that contributes to climate change. Methane consumption, pest suppression, pollination, and bird populations were higher in perennial grasslands.
In addition, the team found that the grass crops’ ability to harbor such increased biodiversity is strongly linked to the fields’ location relative to other habitats.
For example, pest suppression, which is already higher in perennial grass crops, increased by an additional 30 percent when fields were located near other perennial grass habitats. This suggests that in order to enhance pest suppression and other critical ecosystem services, coordinated land use should play a key role in agricultural policy and planning, Landis says.
“With supportive policies, we envision the ability to design agricultural landscapes to maximize multiple benefits,” he says.
However, rising corn and other commodity prices tempt farmers to till and plant as much of their available land as possible. This includes farming marginal lands that produce lower yields as well as converting acreage set aside for the Conservation Reserve Program, grasslands, and wetlands.
“Yes, corn prices are currently attractive to farmers, but with the exception of biomass yield, all other services were greater in the perennial grass crops,” Landis says. “If high commodity prices continue to drive conversion of these marginal lands to annual crop production, it will reduce the flexibility we have in the future to promote other critical services like pollination, pest suppression, and reduction of greenhouse gasses.”
Researchers from the University of Wisconsin, University of Nebraska, Bard College, and Trinity Christian College also were part of this research.
The Department of Energy, the National Science Foundation, and MSU AgBioResearch funded the research.
Source: Michigan State University