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 Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>