Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Food-crop yields in future greenhouse-gas conditions lower than expected

27.07.2006
Open-air field trials involving five major food crops grown under carbon-dioxide levels projected for the future are harvesting dramatically less bounty than those raised in earlier greenhouse and other enclosed test conditions – and scientists warn that global food supplies could be at risk without changes in production strategies.

The new findings are based on on-going open-air research at the University of Illinois at Urbana-Champaign and results gleaned from five other temperate-climate locations around the world. According to the analysis, published in the June 30 issue of the journal Science, crop yields are running at about 50 percent below conclusions drawn previously from enclosed test conditions.

Results from the open-field experiments, using Free-Air Concentration Enrichment (FACE) technology, "indicate a much smaller CO2 fertilization effect on yield than currently assumed for C3 crops, such as rice, wheat and soybeans, and possibly little or no stimulation for C4 crops that include maize and sorghum," said Stephen P. Long, a U. of I. plant biologist and crop scientist.

FACE technology, such as the SoyFACE project at Illinois, allows researchers to grow crops in open-air fields, with elevated levels of carbon dioxide simulating the composition of the atmosphere projected for the year 2050. SoyFACE has added a unique element by introducing surface-level ozone, which also is rising. Ozone is toxic to plants. SoyFACE is the first facility in the world to test both the effects of future ozone and CO2 levels on crops in the open air.

Older, closed-condition studies occurred in greenhouses, controlled environmental chambers and transparent field chambers, in which carbon dioxide or ozone were easily retained and controlled.

Such tests provided projections for maize, rice, sorghum, soybean and wheat – the world's most important crops in terms of global grain production. By 2050 carbon dioxide levels may be about 1.5 times greater than the current 380 parts per million, while daytime ozone levels during the growing season could peak on average at 80 parts per billion (now 60 parts per billion).

Older studies, as reviewed by the Intergovernmental Panel on Climate Change, suggest that increased soil temperature and decreased soil moisture, which would reduce crop yields, likely will be offset in C3 crops by the fertilization effect of rising CO2, primarily because CO2 increases photosynthesis and decreases crop water use.

Although more than 340 independent chamber studies have been analyzed to project yields under rising CO2 levels, most plants grown in enclosures can differ greatly from those grown in farm fields, Long said. FACE has been the only technology that has tested effects in real-world situations, and, to date, for each crop tested yields have been "well below (about half) the value predicted from chambers," the authors reported. The results encompassed grain yield, total biomass and effects on photosynthesis.

The FACE data came from experimental wheat and sorghum fields at Maricopa, Ariz.; grasslands at Eschikon, Switzerland; managed pasture at Bulls, New Zealand; rice at Shizukuishi, Japan; and soybean and corn crops at Illinois. In three key production measures, involving four crops, the authors wrote, just one of 12 factors scrutinized is not lower than chamber equivalents, Long said.

"The FACE experiments clearly show that much lower CO2 fertilization factors should be used in model projections of future yields," the researchers said. They also called for research to examine simultaneous changes in CO2, O3, temperature and soil moisture."

While projections to 2050 may be too far out for commercial considerations, they added, "it must not be seen as too far in the future for public sector research and development, given the long lead times that may be needed to avoid global food shortage."

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>