By Xinhua,
Washington : Researchers from Cornell University has looked “closely” at the soil for the first time — at a scale of 50 nanometers, revealing an incredible variety of organic compounds in it, reported the April issue of Nature Geoscience which is available Monday.
“There is this incredible nanoscale heterogeneity of organic matter in terms of soil,” said Johannes Lehmann, lead author of the study, in a statement on Monday. “None of these compounds that you can see on a nanoscale level looks anything close to the sum of the entire organic matter.”
The authors of the article said that knowing the structure and detailed composition of soil carbon could provide a better understanding of the chemical processes that cycle organic matter in soil.
For example, the research may help scientists understand what happens when materials in the soil get wet, warm or cool and how soils sequester carbon, which has implications for climate change.
The nanoscale soil images were made at Brookhaven National Laboratory using an X-ray spectromicroscopy method, which allowed the researchers to identify forms of organic carbon in the samples.
While the composition of organic carbon in soils from North America, Panama, Brazil, Kenya or New Zealand proved remarkably similar within each sample, the researchers found that within spaces separated by mere micrometers, soils from any of these locations showed striking variation in their compositions. For example, the compounds that “hang on the right and left of a clay mineral may be completely different,” said Lehmann.
The researchers were also able to identify the origins of some of the nano-sized compounds, determining that some of them, for example, were microbe excretions and decomposed leaves. The researchers also recognized patterns of where types of compounds are likely to be found at the nanoscale.
The method now allows researchers to break soil down, separate compounds, conduct experiments on individual compounds and better understand the interactions, Lehmann said.