We have known for quite sometime how Earth i.e. soil acts as a major carbon sink with researchers suggested that there is a limit to the amount of carbon soil can hold; however, a new study has shown that soil is a much larger carbon sink than previously believed.
A Washington State University researcher has discovered that vast amounts of carbon can be stored by soil minerals more than a foot below the surface. The finding could help offset the rising greenhouse-gas emissions helping warm the Earth’s climate.
Marc Kramer, an assistant professor of environmental chemistry at WSU Vancouver, published his findings in one of two related papers demonstrating how the right management practices can help trap much of the carbon dioxide that is rapidly warming the planet.
Estimates suggest that soil is currently holding more than three times the carbon found in the atmosphere, but despite this we are still not in a position to understand how it helps reducing atmospheric carbon-dioxide and how it helps mitigate global warming. Kramer, who is a reviewer for one of three reports issued with the federal National Climate Assessment released last week, compared what we know about soil to how little we know about the deep ocean.
Writing with colleagues from Stanford, Oregon State University and elsewhere in Annual Review of Ecology, Evolution and Systematics, Kramer said more than half of the global soil carbon pool is more than a foot beneath the surface. He also found that soil organic matter at that depth is almost entirely associated with minerals.
Kramer elaborates on the connection this week in the journal Biogeochemistry Letters. His study, which he led with colleagues from Oregon State University and the Stroud Water Research Center in Pennsylvania, is the first to explicitly examine the extent minerals control nitrogen and carbon deep in the soil.
Earlier research by Kramer found that certain farming practices can dramatically increase carbon in the soil. Writing in Nature Communications in 2015, Kramer documented how three farms converted to management-intensive grazing practices raised their carbon levels to those of native forest soils in just six years. While cultivation has decreased soil carbon levels by one-half to two-thirds, the soils he examined had a 75 percent increase in carbon.