November 17, 2009

 

US study shows ozone detrimental to soy yield

 

 

Current atmospheric ozone levels are already suppressing soy yields, according to Agricultural Research Service (ARS) scientists and university cooperators studying the effect of global climate change on crops.

 

ARS plant physiologists, a molecular biologist and a geneticist have been working with University of Illinois scientists on a project called SoyFACE - short for Soybean Free Air Concentration Enrichment - to measure how the projected increases in carbon dioxide (CO2) and ozone will affect soy production.

 

This research supports the US Department of Agriculture priority of responding to climate change.

 

In their studies, scientists found that soy yields increase by about 12 percent at the elevated CO2 levels predicted for the year 2050 - only half of what previous studies estimated.

 

They also found that increased ozone is quite harmful to soy yields, reducing them by about 20 percent.

 

In addition, current levels of ozone are already suppressing soy yields by up to 15 percent, according to data from the ARS Photosynthesis Research Unit in Urbana, Illinois.

 

These results led the scientists to examine the combined effects of CO2 and ozone changes on soy.

 

They found that elevated CO2 partially offsets the ozone damage, confirming general results obtained with open-top chamber studies conducted at other ARS laboratories.

 

The ability of SoyFACE technology to test effects of CO2 and ozone in the open air, without the environmental modifications caused by the chambers themselves, means greater confidence in understanding how plants respond in the real world, including the actual estimates of impact on crop yields.

 

There is much more to be learned about how other interacting factors that affect ozone uptake may come into play by mid-century.

 

Results from these studies will help breeders develop soy varieties better adapted to the changing climate.