Atmospheric changes may affect crops in the future

Atmospheric changes may affect crops in the future

By By Stephen Long, Extension Communications Specialist

URBANA—In making a list of changes in nature that could affect corn and soybean crops in the years ahead, amount of rainfall, quality of the soil, and pest population would probably be at the top. But, one research team at the University of Illinois has “gases in the air” at the top of their list. They are conducting experiments that mimic the content of the atmosphere in the year 2050, specifically ozone and carbon dioxide, and how those changes will affect crops. The project is called SoyFACE—soy, because the project was originally funded to look only at affects on soy. FACE stands for Free-Air gas Concentration Enrichment, which refers to the technique being used to simulate different percentages of ozone and carbon dioxide in the air.

Why carbon dioxide and ozone?

Carbon dioxide has been increasing at a rate of .4 percent per year. Since plants take in carbon dioxide, this has been a positive change for plant production. In fact, rising carbon dioxide has the potential to increase yields by as much as 30 percent. But, those yields are unlikely to be realized with today`s soybean, because varieties are adapted to the atmosphere of a century ago.

Ozone, however has a negative effect on crops. The gas has increased an average of 1 percent per year and is already estimated to have cost agriculture in the United States over $2 billion in lost production. And soybeans are particularly sensitive to ozone.

The problems of surface ozone changes are regional, depending in part on proximity to urban and industrial areas. Illinois is likely to be among the soybean-producing areas with the highest ozone exposure. Concentrations for central Illinois have exceeded thresholds for crop yield reduction in the past years. Because soybean is one of the more ozone-sensitive crops, researchers expect adverse effects on protein, flavanoids and other soybean quality factors if no action is taken.

“Once factors that limit plant physiology are identified,” said Stephen Long, a plant biologist heading SoyFACE, “researchers can use molecular engineering and breeding to develop plants better suited to carbon dioxide levels in the atmosphere today and levels anticipated in the future.”

The FACE facility looks like it could be a new-fangled field irrigation system. It is actually a network of tubing that delivers different concentrations of ozone and carbon dioxide into the air that surround the soybean and corn plants in the test field. The FACE creates a kind of greenhouse without the walls and glass around it. The higher concentrations of gases dissipate as they rise out of the study area and into the general atmosphere without causing any change to the surrounding area.

“The open-air field laboratory gives us an opportunity to look at a whole system in a ‘real-world` way that isn`t possible in greenhouses or controlled chambers,” said Long. “In the FACE facility, we can look at all the biological processes—what`s happening with the plants and soil as atmospheric gases change.”

After its first year in operation, they already observed some remarkable variations due to the changes in atmosphere inside the ring. Photos show that the soybeans growing inside the FACE ring of tubing stayed greener longer because of the elevated level of carbon dioxide than the soybeans growing just inches away, outside of the experimental arena.

“The effects of atmospheric gases on a cropping system are very complex,” said Long. “Once we understand the science behind the changes we can begin to genetically modify the crop or select genotypes and management systems that take advantage of those changes to increase production under levels of atmospheric gases predicted for the future.”

Although there are several other facilities of this kind around the world studying different crops, this one, on the south farms at the U of I campus is the largest, covering 80 acres. The only other FACE crops facility in the United States is in Arizona and is used for cotton and wheat research. The work is funded by an Illinois Council on Food and Agricultural Research (C-FAR) Sentinel Program.

Details on SoyFACE and other research projects will be featured at Agronomy Day 2002, from 7 a.m. to noon, August 22 at the Crop Sciences Research Education Center, located south of the University of Illinois’ main Urbana campus. For more information, including directions and a listing of all of the research projects to be presented at Agronomy Day 2002 visit the Web site: or call (217) 333-4424.

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