The researchers studied three different methods of soybean farming: conservation (no-till drilling); conventional tillage, and organic farming. Their findings showed that the conservation method produced the highest crop yield, 15% more than conventional tillage and 110% more than organic farming. It also held the most carbon in the soil--41% more soil carbon than conventional tillage and 48% more than organic. This catching and holding of soil carbon, called sequestration, keeps carbon from being incorporated into carbon dioxide or other greenhouse gases that contribute to global warming.
"Our research suggests that farmers can make decisions about tillage that can help…mitigate the effects of global warming," writes Harrison and his co-authors.
"Switching from a conventional till method to conservation tillage could…produce 15% more food on the same amount of land," according to the authors. This has serious implications, they write, as the "global population continues to rise and the need to feed more people using less land is becoming more urgent."
For example, the conservation technique would use 52% less land than the organic method to produce the same amount of soybeans.
The research was conducted on a farm in Brighton, Iowa and supported by the U.S. Department of Agriculture and Boston College.
Harrison's area of study focuses on the effects of fossil fuel combustion, acid rain and deforestation on the buildup of carbon dioxide in the atmosphere. At Boston College, he teaches courses on "Biogeochemistry of the Habitable Planet"; "Environmental Geochemistry: Living Dangerously," and "Weather, Climate and the Environment: Global Warming." He earned a bachelor of science degree in chemistry and a bachelor of arts degree in English and American literature at Brown University. He received a master's degree in marine chemistry from the University of California at San Diego's Scripps Institution of Oceanography, and master's and doctoral degrees in geological sciences from Columbia University.
For more information, contact Harrison at 617-552-4653 or at kevin.harrison@bc.edu .