BY ANDREA HILDERMAN
one also has to believe that this commu-
nication can be “read” and understood by
a man-made system.
DeRosa, an associate professor of
chemistry at Carleton, had been engaged
in research related to making responsive
materials, particularly ones that could be
used to deliver drugs. As with many great
discoveries in science, it was a chance
conversation that prompted DeRosa and
Monreal to consider how these responsive
materials might be used in a complete-
ly different setting and for a different
purpose.
“I had an honours student who had
worked with Carlos for the summer,”
DeRosa explained. “Carlos had explained
to him his quest to find ways to improve
nitrogen-use efficiency and prevent
excessive losses. It was that student that
connected us and here we are today.”
“A lot of work has been done already
that shows improved fertilizer efficiency
with smart coatings in a laboratory set-
ting,” she added. “The next step is to see
if these efficiencies are demonstrated in a
greenhouse setting. If so, then field trials
would be on deck.”
Monreal is a research scientist with
AAFC in Ottawa. His expertise includes
the dynamics of interactions between
plant roots and soil micro-organisms—the
organic compounds that roots exude and
how they are linked to nitrogen minerali-
zation and uptake by plants. Monreal’s in-
terest in this area of research was sparked
when he was working on his bachelor’s
degree in Chile in the ’70s.
“I happened to be involved in a nitro-
gen fertilizer research project and I was
measuring how much nitrogen leached
down the soil profile and beyond the reach
of the crop roots,” he said. “That really left
a mark on me—how could these losses be
prevented?”
When Monreal came to the University
of Alberta later on, a constant topic of
conversation was how to prevent nitrogen
losses from fertilizers.
“We tossed this idea around, conducted
research and published results, but noth-
ing concrete was ever developed,” he said.
“At that time, we just did not have the lev-
el of knowledge and analytical technology
available to us that we have today.”
Since the late ’70s, basic research on
soil systems and improvements in analyt-
ical techniques have taken scientists to
the point where they can understand the
chemical language of plants. The basic
premise of this new fertilizer technology
lies in understanding the existence of
communication between living cells in
nature. In soils, plants will signal that
they are deficient in nutrients. In the case
of nitrogen, the plants will send chemical
signals that are detected and captured by
microbes, which then respond to those
signals by producing ammonium nitrate
for the plant.
Detecting the signals has meant that a
nano-biosensor could be developed—piec-
es of DNA called aptamers. “Aptamers
act a lot like antennae,” Monreal said. “If
these aptamers are housed in a polymer
film coating, it could be used to control
the release of the fertilizer inside the coat-
ing until the plant needs it.”
That’s where DeRosa’s research exper-
tise comes into play, developing the smart
coatings that will be required to keep the
nitrogen unavailable until the plant com-
municates that it needs it.
According to Monreal, wheat requires
nitrogen at certain times in its approxi-
mately 100-day growing season. “We’ve
found that at days 25 to 50, most of the
nitrogen is taken up by the plant,” he
said. “Using fertilizer coating containing
aptamers, a smart coating, would enable
the farmer to ensure the nitrogen fertiliz-
er was available when the plant needed it.
It would not be subject to losses through
rain, leaching or gaseous loss.”
The basic research into the organic
compounds that communicate the plant
messages and how microbes respond
with various actions is well understood.
Alberta Innovates Bio Solutions and
AAFC jointly funded early prototype re-
search into this technology in 2012. More
funding has since been received that will
allow for advanced prototype develop-
ment by 2016.
“If everything goes according to plan,
we will be in a position to work with fer-
tilizer manufacturers who are even now
interested in commercialization of this
technology,” Monreal said. “This could be
in a farmer’s field by 2020.”
While there is still a lot of work to be
done in both the greenhouse and the field,
DeRosa believes the biggest barrier to
commercialization is ensuring the coatings
are biodegradable and no residues are left
behind after the fertilizer is released.
Winter
2016
grainswest.com
49
Photo courtesy of Carlos Monreal
MAKING CONNECTIONS:
Carlos Monreal (centre) and Maria DeRosa were connected by
an honours student who had worked with both researchers.
