Washington, May 2 (UNI) A handful of soil is a lot like a banana, strawberry and apple smoothie: Blended all together, it is hard to tell what's in there, especially if you have never tasted the fruits before.
But when you look at soil's organic carbon closely, it has an incredible variety of known compounds.
According to a study 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.
"There is incredible nanoscale heterogeneity of organic matter in terms of soil," said Johannes Lehmann, a Cornell associate professor of crop and soil sciences and lead author of the study.
"None of these compounds that you can see on a nanoscale level looks anything close to the sum of the entire organic matter." The soil measurements (actually, images produced by a highly focused X-ray beam) were made at the National Synchrotron Light Source at Brookhaven National Laboratory using an X-ray spectromicroscopy methoddeveloped by physicists at the State University of New York, Stony Brook.
The method 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.
The method now allows researchers to break soil down, separate compounds, conduct experiments on individual compounds and better understand the interactions, Lehmann said.
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