Navigation Links
Irrigation's impacts on global carbon uptake
Date:8/25/2011

MADISON - 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 (available at http://www.sage.wisc.edu/mapsdatamodels.html). This research was partially supported by a National Aeronautics and Space Administration Applied Sciences Program grant.


'/>"/>

Contact: Mutlu Ozdogan
ozdogan@wisc.edu
608-890-0336
University of Wisconsin-Madison
Source:Eurekalert

Related biology news :

1. Genomewide mapping reveals developmental and environmental impacts
2. Urban impacts on phosphorus in streams
3. Cruise to investigate impacts of ocean acidification
4. Tiny bubbles signal severe impacts to coral reefs worldwide
5. First analysis of invasive plant impacts worldwide
6. US farmers dodge the impacts of global warming -- at least for now
7. Seafloor recovery from fishing gear impacts in Stellwagen Bank Marine Sanctuary slow, unstable
8. Gulf oil spill similar to Exxon Valdez in initial social and mental impacts, study finds
9. Latest report on North American industrial pollution reveals impacts on our shared water environment
10. Epidemiological tree study shows impacts of climate change on forests
11. Human impacts on the marine ecosystems of Antarctica
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/25/2016)...   Unisys Corporation (NYSE: UIS ) today announced ... International Airport, New York City , to help ... to enter the United States using passports ... pilot testing of the system at Dulles last year. The ... during January 2016. --> pilot testing of the ...
(Date:1/20/2016)... A market that just keeps on growing. Molecular Diagnostics ... genomics knowledge. Learn all about it in this new ... trends are pushing market growth and company valuations. Trends ... pathogen evolution - next generation sequencing - emergence of ... the role of genetic material in Disease and Health ...
(Date:1/13/2016)... , January 13, 2016 ... has published a new market report titled - Biometric Sensors ... and Forecast, 2015 - 2023. According to the report, the global ... and is anticipated to reach US$1,625.8 mn by 2023, ... 2023. In terms of volume, the biometric sensors market ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... , Feb. 10, 2016 NX Prenatal Inc., ... proprietary NeXosome® technology for early warning of adverse ... most recent study by Dr. Thomas McElrath ... Society for Maternal Fetal Medicine,s (SMFM) annual meeting held ... th , 2016.  The presentation reported initial positive ...
(Date:2/10/2016)... New York, and New York, New York (PRWEB) , ... ... ... Regeneron Pharmaceuticals Inc. (NASDAQ: REGN) today announced that it ... and develop new vaccines and immunotherapies for infectious diseases and cancer. ...
(Date:2/10/2016)... 10, 2016  Allergan plc (NYSE: AGN ) ... Brent Saunders , Allergan,s CEO and President, will be ... session at the RBC Capital Markets Healthcare Conference on ... The New York Palace Hotel in New ... live and can be accessed on Allergan,s Investor Relations ...
(Date:2/10/2016)... ... February 10, 2016 , ... Benchmark ... today the promotion of two long-standing principal investigators (PI) to the roles of ... Research and Development. , Dr. Laurence Chu, a Benchmark Research PI in the ...
Breaking Biology Technology: