December 12, 2006

Modeling program to track farm tilling practices

by K.C. Jaehnig

CARBONDALE, Ill. -- A computer-aided modeling program developed at Southern Illinois University Carbondale will provide information on the relationships between economic factors, "green" farming practices and environmental results.

Luba Kurkalova, an assistant professor of agribusiness economics, and doctoral student Mark E. Carlos, have spent much of this year collecting data from the lower Illinois River Basin to construct the model.

Once it's done — in another six to nine months, Kurkalova estimates — they should have a tool that can predict where and when farmers would switch to less intensive tilling systems and how many acres would be involved should fuel prices rise or new conservation policies come into play.

"This would be extremely useful information for policy makers, for agencies like the Illinois EPA and for any conservation programs financed with taxpayers' money," Kurkalova said.

The state's Council on Food and Agricultural Research is funding the project.

Farmers using conservation tillage practices don't aspire to the "clean" fields their grandfathers plowed. What's left in the fields after harvest stays in the fields; the following spring, farmers either go ahead and plant without bothering to clear out whatever the weather didn't break down or do just a light once-over. That leftover plant material not only helps keep soil in place but also cuts down on the amount of farm chemicals washing off the ground and into creeks and streams.

"This kind of tillage is one of the most effective conservation practices on land that remains farmed," Kurkalova said.

It also uses less fuel, making it much more attractive to farmers when gas prices spike.

Kurkalova and Carlos are assembling their model using information from a region in which many farmers already have switched to conservation tillage, which should make it extremely accurate.

"We're basing it on observed data, so what we will have is a model with very fine spatial resolution, "she said. "This means we will be able to make predictions using much smaller spatial units.

"For example, one farmer might have pretty dense soil, while another might have soil with low clay content. What the model will be able to do with finer spatial resolution is to predict the differences between one farmer and another."

The immediate goal focuses on the link between fuel prices and conservation tillage. On down the road, policy makers could use it to get a handle on where farmers would most likely use tillage to cash in on the Illinois Conservation and Climate Initiative, the state's new "carbon credit" project.

The initiative, launched at the beginning of this year, lets farmers and other landowners earn credits by adopting practices — conservation tillage among them — that reduce greenhouse gas emissions. The Chicago Climate Exchange buys large blocks of these credits and sells them to companies, cities and others that continue to emit such gasses. The buyers can then "subtract" their purchased credits from their output of greenhouse gasses, thereby reducing their emissions record.

"The basic idea is that farmers will be paid for the use of conservation tillage and some other conservation practices that sequester carbon, such as grass and tree planting (and the use of manure digesters)," Kurkalova said.

"There's quite a bit of interest in it, and one of the things this model would be able to predict would be where we might see conservation tillage initiated in response to this initiative."

Kurkalova also is interested in discovering exactly how changes in tillage systems relate to environmental changes, particularly when it comes to water quality.

"There are models developed by hydrologists that can do this, and we have a very strong team of hydrologists and water resources engineers here at SIUC," she said.

"That's a logical extension — a next step."

Leading in research, scholarly and creative activities is among the goals of Southern at 150: Building Excellence Through Commitment, the blueprint the University is following as it approaches its 150th anniversary in 2019.