Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Irrigation's impacts on global carbon uptake

26.08.2011
Globally, irrigation increases agricultural productivity by an amount roughly equivalent to the entire agricultural output of the U.S., according to a new University of Wisconsin-Madison study.

That adds up to a sizeable impact on carbon uptake from the atmosphere. It also means that water shortages — already forecasted to be a big problem as the world warms — could contribute to yet more warming through a positive feedback loop.

The new research quantified irrigation's contribution to global agricultural productivity for the years 1998-2002, estimating the amount of carbon uptake enabled by relieving water stress on croplands. The results published August 25 in the journal Global Biogeochemical Cycles, a publication of the American Geophysical Union.

"If you add up all the annual productivity that comes solely due to irrigation, it adds up to about 0.4 petagrams of carbon, nearly equivalent to the total agricultural productivity of the United States," says study author Mutlu Ozdogan, a UW-Madison professor of forest and wildlife ecology and member of the Nelson Institute for Environmental Studies.

The study also shows quantitatively that irrigation increases productivity in a nonlinear fashion — in other words, adding even a small amount of water to a dry area can have a bigger impact than a larger amount of water in a wetter region. "More irrigation doesn't necessarily mean more productivity," Ozdogan says. "There are diminishing returns."

This was already known on the field scale, he says, but is true globally as well. Interestingly, he found that, on average, worldwide irrigation is currently conducted close to the optimal level that maximizes gains. While this may be good news for current farmers, it implies limited potential for irrigation to boost future productivity even as food demands increase.

The study takes an important step toward quantifying how management decisions can impact global carbon balance and assessing the economic worth of water and carbon in irrigated landscapes.

"Now that we have spatially-explicit maps of how much irrigation is increasing carbon accumulation, we have good information about the value of the water going into those areas. We might be able to come up with a value of carbon in those areas as well," he says. "Of course the flip side of this is that, in many places around the world, if we keep irrigating we are either going to run out of water or degrade soils because of salinity issues."

The current study does not factor in any impacts in areas from which irrigation water is drawn. However, Ozdogan says, a better understanding of the links between irrigation, productivity, and carbon will help researchers look at downstream effects of factors that influence each of those elements — for example, how water shortages in agricultural regions may affect regional carbon cycles and climate.

The study continues a history of work from the UW-Madison's Center for Sustainability and the Global Environment that includes the development of several freely available climate and ecosystem models, maps, and datasets. This research was partially supported by a National Aeronautics and Space Administration Applied Sciences Program grant.

Mutlu Ozdogan | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>