Recent studies show that two types of grasses could serve as more environmentally and economically favorable feedstocks for biofuels than corn.

Madhu Khanna, professor in agricultural and consumer economics, and Atul Jain, professor in atmospheric sciences, collaborated to study the potential of miscanthus and switchgrass to be grown as bioenergy crops in the Midwest.

The goal of producing ethanol from plants, including corn and other bioenergy crops such as grass, is to derive energy from sources other than fossil fuels in order to reduce carbon emissions that cause climate change and lessen the country’s dependence on foreign oil, Jain said.

While corn ethanol is becoming more widespread, it has a number of drawbacks associated with it that may prevent it from being a sustainable biofuel source.

“As we divert more and more corn to fuel production, we take it away from the food and feed market,” Khanna said. “That’s going to raise food prices, unless corn productivity increases at much greater rates than in the past.”

Additionally, there is an interest in discovering crops that are higher yielding and can be grown on low-quality soil, making use of land that is currently not productive for food and feed crops, Khanna said.

The government is investing in the development of alternative biofuels, which may have benefits over corn.

“These grasses are promising both from an energy security perspective, as well as a climate change mitigation perspective,” Khanna said.

According to Khanna, the goal of these studies was to determine the biophysical potential of miscanthus and switchgrass and perform a detailed analysis of the economic feasibility of growing them in various regions in the Midwest.

“The viability of these grasses differs across locations,” Khanna said. “We wanted to analyze their viability not just at a representative location, but see how it differs spatially across different regions.”

In order to analyze the viability of these grasses, data was gathered from each 10-kilometer region throughout the Midwest regarding “the soil type, climate conditions, nutrient stability, and (solar) radiation,” Jain said.

“We (also) took into account the cost of planting, harvesting, maintaining, storing and transporting them,” Khanna said.

The information gathered from field experiments in Illinois, together with information about the current yields of regular crops, was used with a biophysical and economic model, Khanna said. The model, which consists of mathematical equations, was used to estimate the breakeven prices farmers need to receive for growing these grasses in the Midwest.

They also found that climate could have an effect on the growth of these grasses.

“In the northern part of the Midwest, like Minnesota and Wisconsin, the yield of miscanthus drops dramatically because it’s not as cold-tolerant,” Khanna said.

Being perennial plants, the grasses do not require replanting each year, which has both financial and environmental benefits.

“Miscanthus has a longer life (than switchgrass), that could be as long as 20 years, which means that farmers plant it once and then they just need to maintain it,” Khanna said. Miscanthus was also found to be about two times more productive than switchgrass in most regions.

Disturbing the land each year to replant, as is the situation with corn, causes carbon dioxide that is present in the soil to be released into the air, which may contribute to ozone depletion and climate change.

“If you don’t disturb the land, then all the carbon and all the nutrients will remain in the soil, and much less will get released into the atmosphere, and it is good for climate change,” Jain said.

Additionally, the plants require less fertilizer and chemicals to maintain, and they are good at sequestering carbon in the soil, Khanna said.

“There are a number of environmental features that (miscanthus) has as well as its yield, which makes it a very desirable energy crop,” she said.

The next step of this research is to extend the analysis to include land all over the U.S., Jain said.

“We need to think about it: If we go to much higher altitudes or if we go to much warmer climates, can we grow these crops?” he said. “We don’t have that information. More measurements are required to make our modeling better.”

Once more data is acquired and a shift is made toward these alternative biofuel sources, the technology will hopefully be in place to efficiently convert the grasses to ethanol on a large scale.

“Various companies are producing and developing the various technologies and scaling it up for commercial production,” Khanna said. “In the next two to three years, it could be available, but it’s hard to say.”

Haixiao Huang, a research associate who works with Khanna, says governmental policies may be needed to facilitate production of alternative bioenergy crops in the Midwest.

These include policies which would provide incentives for farmers to convert their land to the production of bioenergy crops, such as miscanthus and switchgrass, Jain said.

“In (the Midwest), corn and soy are the dominating crops, and there is government support for these crops,” Jain said. “Until farmers see similar benefits from energy crops (such as grass) in terms of the dollar amount, they’re not going to favor these crops.”

Jain said they hope these studies “help provide information to farmers about the locations where these crops are more productive and the breakeven prices at which it would be economically viable to grow them.”