Carbon Buried in Soil by Erosion Will Be Re-Released into Atmosphere

A new source of carbon emission has been identified by a research team from the University of California, Davis. It is assumed that this source could play better role in understanding past and future global change.

Prior to this there were studies that found that erosion can trap the carbon in soil being the perfect carbon sink or storage. But this new study highlights the fact that the part of that sink is only temporary.

"It's all part of figuring out the global carbon cycle," said co-author Johan Six, professor of plant sciences at UC Davis. "Where are the sources and where are the sinks? Erosion is in some ways a sink, but, as we found out, it can also become a source."

It was estimated by the researchers that half of the carbon embedded in the soil by erosion will be released again into the atmosphere within 500 years. This process could be faster as a result of climate change. Climate change can intensify the rate of decomposition, aiding the release of the buried carbon.

For the case study, the researchers used radiocarbon and optical dating to calculate the amount of carbon emissions captured in soils and released to the atmosphere during the past 6,000 years along the Dijle River in Belgium.

"Our results showed that half of the carbon initially presents in the soil and vegetation was lost to the atmosphere as a result of agricultural conversion," said study co-author Gert Verstraeten, a professor at KU Leaven, Belgium.

Six also states that, erosion could be minimized by no-till and low-till agricultural methods, as well as by cover cropping, which can ensure that soil is not left bare.

"We need to know where and how much carbon is being released or captured in order to develop sensible and cost-effective measures to curb climate change," said lead author, Kristof Van Oost, of the Universite catholique de Louvain in Belgium.