Great Plains agricultural greenhouse gas emissions could be eliminated

FORT COLLINS, Colo., Aug. 5 (UPI) -- Researchers have recently completed a historical survey of greenhouse gas emissions from agricultural industries across the Great Plains. Their work has revealed the possibility of eliminating agricultural emissions from the region.

Using a combination of computer modeling and census data, scientists from the Natural Resource Ecology Lab at Colorado State University estimated and catalogued emissions totals from Great Plains agricultural sources between 1870 and 2000. Sources included cropping, livestock raising, irrigation, fertilizer production and tractor use.

"Carbon released during the plow-out of native grasslands was the largest source of greenhouse gas emissions before 1930," William Parton, senior research scientist at the lab, said in a press release. "Livestock production, direct energy use for tractors and irrigation, and soil nitrous oxide emissions from nitrogen fertilizer application are currently the largest sources."

Parton is the lead author of a new paper on the research, published in the journal Proceedings of the National Academy of Sciences. He says the work suggests the adoption of a few eco-friendly agricultural best practices -- no-tillage agriculture and slow-release fertilizer -- could dramatically reduce the region's carbon footprint.

"If just 25 percent of agricultural producers in the region adopted these practices, we estimate a 34 percent reduction in greenhouse gas emissions," Parton said. "If 75 percent of them adopted the practices greenhouse gas emissions from agriculture in the region could be completely eliminated."

More than just present a path forward, the research highlights the dramatic ways in which human activities alter the ecosystem. As farmers replace man and animal labor with machines and shifted more resources to livestock management to meet the growing demand for meat, these sources became the region's dominant sources of greenhouse gas emissions.

Emissions increases from these sources overwhelmed reductions gained from improved efficiency, increased irrigation and a reduction in crop land.

"Fortunately, new farming strategies have the potential to reduce those greenhouse gas emissions and diminish agriculture's impact on the environment in the future," said Myron Gutmann, director of the Institute of Behavioral Science and professor of history at the University of Colorado, Boulder.

Researchers acknowledge that changes in management practices don't come cheaply. Slow-release fertilizers are more expensive, and no-tillage farming sometimes requires new equipment and training. But scientists point out that USDA programs have been set up to defray the costs of these beneficial changes.

Emissions on the Great Plains aren't constant. In addition to changes in human behavior, fluctuation in climate can both exacerbate and mitigate the release of greenhouse gases. Cool, wet years typically lead to reduced emissions, while hot and dry spells bolster carbon emissions.

Scientists worry that a warming climate could precipitate more frequent hot and dry spells in the region. Global warming, combined with increased farmland conversion compelled by rising food prices, could significantly grow the region's carbon footprint if steps toward mitigation aren't taken.