Model predicts yield, stability of bioenergy crops

By Eric Fries

A new study hopes to aid farmers in the production of bioenergy crops. The study, led by atmospheric sciences professor Atul Jain, models the yield and stability of three different bioenergy crops over various geographic regions.

These crops could be used as alternatives to corn for the production of ethanol.

This is the first study of this type that has been conducted on such a large scale and included data about the stability of the crops, Jain said. The model can assure farmers that growing bioenergy crops will produce a good, long-term return on their investment and can also help decide what crops are best suited to their land.

Jain and his team are currently working to make the results of the study available to farmers and the public.

Data was collected and compiled by Yang Song, Ph.D student in LAS, under the guidance of Jain. The model includes data collected between 2001 and 2012 at more than 75 sites across the U.S. Three different species of grasses were studied: miscanthus, and two different cultivars of switchgrass, Jain said. 

“We need to understand the relationship between the environmental conditions and the growth of those grasses — how the different environmental factors will control it,” Song said. “That is the most important part of this research.” 

The data, collected at smaller-scale research plots, was used to create a model that can estimate and predict the yield and stability of the crops at other locations and on a larger commercial scale.

“The major issue is that we cannot grow these crops everywhere. There are certain environmental conditions that favor them to grow in certain parts of the world,” Jain said. “And these are not really well-established crops at this time. Although we can get high yields from these crops, there are certain issues.”

Jain believes it’s important to shift ethanol production away from corn to alternatives such as these grasses because of environmental and food supply problems associated with corn. 

One problem with using corn to produce ethanol is that there is less corn that can be used for food, which can cause a shortage and raise food prices. 

“There is a competition between the food vs. the energy,” Jain said. 

In addition, the growth of corn for ethanol has environmental repercussions. 

Corn growth requires a lot of nitrogen fertilizer, which has resulted in nitrogen leeching and pollution of the soil and water, Song said.

The grasses included in the model would minimize these effects if used instead of corn. 

“The best thing about those grasses is that they don’t invest a lot of the nitrogen because they can recycle their nitrogen by themselves,” Song said. 

Growth of these grasses could help cut down the nitrogen leeching and reduce the emission of greenhouse gasses into the atmosphere, she said.

Jain said in areas where solar and wind energy are less available or more costly to generate, bioenergy crops are often more beneficial. They are especially important in areas such as the Midwest, he said. 

“I think we have plenty of land here, and the land is quite fertile,” Jain said. “I believe that if we can use part of this land to grow energy crops, perhaps it could be beneficial not only to the farmers, but also to the users.”

Eric can be reached at [email protected]