NASA Research Reveals Soybean Damage Near $2 Billion

HAMPTON, Va., May 27 /PRNewswire-USNewswire/ -- Rising surface ozone
concentrations are damaging nearly $2 billion in annual U.S. soybean crops, a
NASA study of satellite measurements indicates.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

The study, headed by NASA Langley Research Center in Hampton, Va., was
presented at the American Geophysical Union Joint Assembly meeting, May 24 in
Toronto and looked at five years of soybean yields, surface ozone and
satellite measurements of troposphere ozone levels in three Midwest states.
Indiana, Illinois and Iowa are three of the biggest soybean producers in the
U.S. and had peak crop damage in the hundreds of millions -- part of more than
$2 billion nationwide.

"In the 19th and early 20th century, background surface ozone concentrations
were relatively low so that an increase of 25 percent, (5 to 10 parts per
billion), didn't affect living organisms," said Jack Fishman, a research
scientist at NASA Langley's Science Directorate. "But now, we've crossed the
line where you can expect to see modest increases in surface ozone result in
crop growth being stunted."

Ozone can protect or harm life on Earth. Six miles above the surface, ozone in
the stratosphere is a shield from the sun's harmful ultraviolet radiation. In
the troposphere or the closest layer (surface to 6 miles) ground-level ozone
is a pollutant made from reactions between sunlight and human-induced
emissions - harmful to breathe and damaging to plants.

The severe heat of the Midwest each summer has combined with manmade emissions
to create smog and increasingly higher levels of its primary component,
surface ozone, over the past several decades.

Fishman, former NASA Langley employee Jack Creilson and other researchers used
soybean crop yield data during a 5-year period over the Midwest and analyzed
the results using multiple computer models. The results are consistent with
conventional ground-based measurements and with data obtained from an open-air
experimental facility SoyFACE (Soybean Free Air Concentration Enrichment) at
the University of Illinois at Urbana-Champaign. Their analysis suggests that
the cost to the farmers globally is substantial, and supports other studies
that calculate an economic loss of more than 10 billion dollars annually.

Until now, the question of ozone impact on crop yield was mostly addressed by
closed, chamber studies and on a larger scale at open-air facilities like
SoyFACE. The study proved that space-borne satellite measurements of
troposphere ozone - derived from NASA's Total Ozone Mapping Spectrometer
(TOMS) prior to 2005, and from the Ozone Monitoring Instrument (OMI) since
2005 - are useful indicators of surface ozone concentration over a far broader
area than ground-based monitors.

The study used both satellite and surface observations of ozone, historic
yield data and a sophisticated statistical model that also included factors
such as ozone, temperature and soil moisture.

Creilson, now at the Climate System Research Center at the University of
Massachusetts, said the advantage of the satellite-derived method is that it
can be used worldwide. Poorer countries have little monitoring capability and
even in the U.S., croplands are so vast that a land-based network of ozone
sensors would be extremely expensive to construct and maintain.

"You have these farming locations that have no way of measuring surface
ozone," Creilson said. "What we had to do was come up with a way of showing
them there's a benefit of having the information."

For more information about this and other NASA research devoted to finding out
how the earth and its atmosphere are interacting and changing, go to:

http://science.larc.nasa.gov/

SOURCE NASA

Chris Rink of NASA, +1-757-864-6786, +1-757-344-7711,
christopher.p.rink@nasa.gov