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[Lawrence London <lfljvenaura@gmail.com>]

Researchers discover high-def electron pathways in soil | Cornell Chronicle
http://www.news.cornell.edu/stories/2017/03/researchers-discover-high-def-electron-pathways-soil

Researchers discover high-def electron pathways in soil
By
Blaine Friedlander <bpf2@cornell.edu>
[image: root hairs]
<http://www.news.cornell.edu/sites/chronicle.cornell/files/LehmannSunROOTcarbon460.jpg?itok=BWNSQo9G>
Kelly Hanley/Lehmann Lab
Under a microscope, root hairs grow into pyrogenic carbon particle, which
enhance electron networks. Plants grow more efficiently than previously
thought.

All plants need electrons to aid biological and chemical tasks. Cornell
scientists have discovered a new high-definition system that allows
electrons to travel through soil farther and more efficiently than
previously thought.

“Microorganisms need electrons for everything they do. If they consume
nutrients or spew out methane or expel carbon dioxide – for any living,
biological process – they need electrons,” said Tianran Sun, postdoctoral
researcher in soil and crop sciences and lead author of the paper that
appears March 31 in Nature Communications.

Like large volumes of electricity that flow from Niagara Falls throughout
upstate New York, electrons convey through soil via carbon. “We weren’t
aware of this high-definition soil distribution system transporting
electrons from far away. It’s not kilometers, it’s not meters, but
centimeter distances that matter in soil,” said Johannes Lehmann, professor
of soil science.

In fact, amending the soil with pyrogenic carbon – known as biochar –
brings high definition to the electron network. In turn, the electrons spur
conductive networks and growth, said Sun.

“Previously we thought there were only low-performing electron pathways in
the soil – and now we’ve learned the electrons are channeled through soil
very efficiently in a high-performing way,” said Lehmann.

Lehmann and the members of his laboratory had struggled to understand why
microorganisms thrived in the presence of biochar. The group removed soil
phosphorus, making the environment inhospitable. They ruled out water and
nutrients. They discarded the use of biochar as a food source because
microorganisms cannot consume much of it. Through Sun’s background in
environmental chemistry, the scientists found that microorganisms may be
drawn to electrons that the biochar can transport.

 “These results will lead to a better understanding of microbial responses
in soil and microbial metabolism, including long-term effects on greenhouse
gas emissions,” Sun said.

In addition to Lehmann and Sun, who published “Rapid Electron Transfer by
the Carbon Matrix in Natural Pyrogenic Carbon,” the paper’s other authors
are Barnaby Levin, doctoral student in applied and engineering physics;
doctoral student Juan Guzman, biological and environmental engineering;
Akio Enders, technician, soil and crop sciences; David Muller, professor of
applied and engineering physics; and Lars Argenent, professor, University
of Tübingen, Germany.

Lehmann credits cross-disciplinary work with finding this idea. “I could
not have completed this work without Tianran Sun’s chemistry expertise, nor
without Lars Angenent’s microbiology expertise, or David Muller’s or
Barnaby Levin’s physical knowledge of carbon structure,” said Lehmann.
“They played a big part.”

The National Science Foundation and the U.S. Department of Agriculture
funded this research.