BROOKINGS, S.D. - Farmers in the Northern Plains often worry about what the weather will do to their crops, but seldom do they give thought to how the plants in their fields could affect the weather.

A new NASA-funded study at South Dakota State University will tackle that question by asking how a potential move from corn and soybean crops to perennial grasses grown primarily to fuel our cars could alter regional weather patterns and the risk of wildfires.

Scientists at SDSU's Geographic Information Science Center of Excellence and their collaborators will use a variety of field and modeling approaches to look at the potential impacts of such a shift in South Dakota, North Dakota, Nebraska, western Minnesota and northern Iowa under various scenarios of biofuel cultivation, said Geoff Henebry, an SDSU professor and senior scientist at the center.

Many factors can change the seasonal cycle of exchanges of water and energy between the land and the lower portion of the atmosphere, Henebry said.

For instance, perennial grasses will use more water early in their growing season than corn or soybean plants.

"As you change the land surfaces, you change the characteristics of the seasonality of the vegetation growth and water use and the brightness," he said.

Senior scientist Michael Wimberly said the researchers are not trying to predict exactly what will happen. Their goal is to make some broad but reasonable assumptions so potential consequences can become part of the discussion.

"What we're trying to do is come up with logical and reasonable projections that may give us essentially a look at some different visions of what a future biofuels world might be like," said Wimberly, an SDSU associate professor.

A good start is the "Billion Ton Study" from the Oak Ridge National Laboratory, which sets a goal of using 1 billion dry tons of biomass to displace 30 percent of the nation's petroleum consumption for transportation by 2030.

The SDSU project will bracket the possibilities by looking at the Oak Ridge study and the current corn and soybean landscape as extremes, figuring that reality will fall somewhere in between, Wimberly said.

The $738,000 study is a collaboration among scientists at the geological center, other SDSU departments, the South Dakota School of Mines & Technology and the U.S. Geological Survey's EROS Data Center near Sioux Falls.

It's timely because it involves feedstocks such as switchgrass that are used for biofuel - the anticipated next step in ethanol production.

Wimberly said that within the Northern Plains sit numerous acres of harvested crop land, other crop land, pasture and lands enrolled in CRP or wetland programs.

"There's not only a lot of active stuff. There's a lot of stuff that could be pushed into production under the right conditions," Henebry said.

Behind the scenes of the SDSU study is a remote sensing evapotranspiration model originally developed as a famine early warning system. The model's creator - Gabriel Senay, an SDSU adjunct faculty member based at the EROS Data Center - is a member of the research team.

Henebry said the scientists will take Senay's model and incorporate other computer intensive weather imaging models and data from carbon flux towers to look at potential effects.