November 18, 2009
Study explores ramifications of biofuel production
CARBONDALE, Ill. -- Everyone knows that fuel made from plants is good for the environment. But what if there are cases where that’s not true?
“A major rationale behind our current biofuel policy is the hypothesis that these fuels -- particularly second-generation fuels (produced from crop waste material or from plants not used for food) -- have a variety of benign attributes, from their net carbon footprint to lower fertilizer use and nutrient losses,” said Silvia Secchi, an economist in the College of Agricultural Sciences at Southern Illinois University Carbondale.
“But if, for example, prices for biomass feedstocks increase, that could draw more environmentally fragile land into production and increase tillage intensity and nitrogen fertilizer use. One of the things our study looks at is the impact of biomass feedstocks on land productivity and the environment at a very fine scale, something few other studies have done.”
Secchi is part of a team of economists, environmental scientists and a statistician engaged in a detailed look at the links between agriculture, energy and the environment. A three-year, $360,000 grant from the U.S. Department of Agriculture’s Cooperative State Research, Education and Extension Service underwrites the project. In addition to determining the environmental consequences of biofuel production, the researchers also are examining the economic implications, all with an eye toward developing policy recommendations for this potential new financial sector.
While biofuels can be made from any number of plant materials, the team is focusing on ethanol manufactured from corn stover — the leaves, stalks, husks and cobs left behind after harvest. Although a formal stover market for biofuel does not yet exist, the fact that farmers have years of experience growing corn and could boost their per-acre profit by selling both grain and gleanings makes the emergence of such a market a good bet.
But if farmers grow more corn, that increased production would ripple out to affect everything from the price they get for it to the cost of oil and gas.
“Every movement you make in crop production has ramifications on a variety of fronts, so to get a better understanding of the whole, you need to link crop production models with energy and commodity market models,” Secchi said. “That’s part of what we’re doing,”
Some members of the team are concentrating on the big picture: the interaction between world-scale energy and commodity markets and the resulting effects on the development of a stover market.
Secchi and her research partner Luba Kurkalova, a North Carolina Agricultural and Technical State University colleague formerly at SIUC, are homing in on the fine details. What happens if farmers grow more corn? Will they work existing acres more intensively or begin planting on land previously left fallow? Will greater production lead to less carbon storage in the soil? More erosion and chemical run-off? What are the trade-offs between using stover for biofuel and using it to improve and protect the soil and reduce pollution from farm chemicals?
The pair already has found that higher stover prices do lead farmers to plant both their less productive fields (requiring more fertilizer) and those that tend to erode. Kurkalova reports that even productive fields are losing carbon content as cropping increases, while Secchi has detected large increases in run-off in Midwestern states where corn production has risen as well as significant environmental impact on acreage that farmers brought back into production after letting it sit idle for some years.
“We’re trying to get a better handle on this because it could be quite important not just from an environmental standpoint but from a policy standpoint, too,” Secchi said.
“When you’re making policy, you try to avoid having unintended consequences.”
The project relies heavily on computerized simulation models to predict outcomes of different scenarios involving commodities, energy and the environment. While economists and other scientists often use such models in their research, models aren’t perfect predictors. In this case, the data used in constructing them has gaps because biofuels have not been available for very long, their markets are still developing, commodity and energy prices are volatile, technology is changing rapidly and government policy is in flux.
“We’re working with things that don’t exist in the real landscape,” Secchi said. “In addition, each model has a certain amount of inherent uncertainty. As you add models, you add uncertainty.
“But if you want to have good policy, you have to have good estimates of what’s involved. That’s what we’re trying to do.”