A recent study has found that topsoil erosion, besides reducing crop productivity, causes the release of greenhouse gases. But the study, whose co-authors include Rattan Lal, director of CFAES’ Carbon Management and Sequestration Center, also found that eroded topsoil can be restored, and its negative impacts reversed, faster than had been previously thought.
“The general statement is that forming 1 inch of topsoil may take thousands of years,” said Lal, who is Distinguished University Professor of Soil Science in CFAES’ School of Environment and Natural Resources. But he said that adding organic matter—in the study’s case, composted manure—to eroded land can reduce that time significantly.
The study, which was started in 1997 at CFAES’ Waterman Agricultural and Natural Resources Laboratory in Columbus, appeared late last year in Scientific Reports, part of the high-impact Nature family of journals. The findings are important, Lal said, because topsoil erosion is a concern both for farmers trying to stay profitable and for nations trying to feed all their people, while they also at the same time try to protect their environments. He said that globally, about 4 billion acres are affected by erosion. And, as he and his co-authors wrote in the study, the impacts of that erosion, such as shrinking crop yields, often happen so slowly that they “may not be recognized until crop production is no longer economically viable.”
It’s for that reason that soil erosion is called “the quiet crisis,” Lal said.
The study’s findings are important, too, because overwhelming scientific evidence shows that rising levels of greenhouse gases are causing Earth’s climate to change. The study specifically found methane and nitrous oxide among the gases released by erosion. Both are much stronger than the most common greenhouse gas, carbon dioxide. KURT KNEBUSCH