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Charged Stake Mimics Roots

Probe Gauges Plants' Access To Nutrients

 by Gord Leathers

A growing number of Manitoba
farmers are enjoying the benefits of a
new way of testing soil fertility and it's
helping them make better crop deci-
sions. It's done with the plant root
simulator (PRS), an award-winning
technology developed by Western Ag
Innovations at Saskatoon.
"It's working for me," said
Armand Neufeld, who farms near
Killarney. "It reduces my fertilizer
costs and I'm getting the equivalent
or better yields out of this than what
I used to."
The 2,000-acre Neufeld spread is
part of the 1.6 million acres of
farmland that will be evaluated and
fertilized based on data from the
PRS. It's a combination of data
gathering with the probe and num-
ber crunching with an advanced
computer program.
Altogether, the service costs $1.50
an acre, but Ken Harms of Ken's
Crop Care in Killarney said more
and more farmers are testing their
fields this way.
"We're likely looking at about 75
to 80 customers within about a 100-
mile radius around Killarney," he
said. "I have about 25 guys who test
their whole farm on an annual basis."
In traditional soil tests, samples
taken from the field are analysed
for chemical compounds, but the
PRS probe takes this process a
step further.
Samples taken from the farm are
tested with a resin-coated probe.
"This thing sees nutrients the way
plant roots would see them,"
Harms said. "Whereas the tradi-
tional chemical extraction method
tells you what's there, it doesn't tell
you actually whether it's available
or isn't available."

  The probe is a plastic rod, coated
in a-resin that makes the probe
behave the way a plant root does. It
has a tiny electrical charge on its sur-
face and this helps the probe collect
nutrients the same way a plant root
does at the microscopic level. These
nutrients are collected from the sur-
face of the probe so it not only shows
their presence, but whether plants
can gain access to them in the soil.
"I think it's a different approach
and it gives a bit of insight into how
the physical condition of the soil
might influence availability,"
explained University of Saskatchewan
soil scientist Jeff Schoenau, who
helped develop the probe. "It's very
useful when it comes to nitrogen and
phosphorus. for mineralization and
release from the solid phase."
The numbers generated by the
probe are fed into a computer pro-
gram that looks at different soil fac-
tors, such as clay and sand content,
as well as moisture and type crop you
intend to grow. What pops up in the
windows along the sides are recom-
mendations for fertilizer and a pre-
dicted yield. By changing the num-
bers, a farmer can see how the com-
puter predicts changes in yield. The
results are summed up with a yield
estimate after harvest, right down to
costs and returns.
"The PRS forecaster gives a very
powerful insight into the kind of
balance and amounts of different
fertilizer nutrients that are needed to
maximize return on the fertilizer
input dollars," said Ken Greer, the
other soil scientist who helped
develop the probe. "It's notjust a soil
test, it's a tool to manage your pro-
ductivity and, I think, a powerful
tool in crop nutrition planning."
  Neufeld agreed. The tests done on
his fields recommended he
could reduce the level of fertilizer
he used but still maintain his yields.
"One very interesting thing was
my phosphate use," he said. "It
required very little phosphate on
some fields, so I cut way back on it
and the yields were still very good.
Instead ofblanketing my farm with
nitrogen, which is skyrocketing this
year, the costs of nitrogen are down
significantly and also other inputs."
The PRS may also be used for field
planning. Once the computer has
crunched the numbers and shown
the potential yields, a farmer may
decide to run With a different crop.
"Guys sometime have it predeter-
mined and decide that this field is
where I'll grow barley this spring,"
he said. "But when we look at the
nutrient levels in the soil and at what
barley actually requires, we're maybe
better off planning a different crop
that's going to make us more money
on the farm."
The PRS probe and software were
recognized by the National Science
and Engineering Research Council
(NSERC) with a Synergy Award for
innovation, presented to Schoenau
and Greer, who are both farmers as
well as soil scientists.
"It's an award that's put out by
NSERC and it recognizes on a
national level, innovation and part-
nership between researchers and
industry to take an idea from prod-
uct to a commercial entity and suc-
cess," Schoenau said.,
"The awarq is great: Greer added,
"But without the service reps and
WIthout the customers actually buy-
ing this, there would have been no
reason to give us the award, So really
it's all thanks to the customers."
There are currently three field
representatives in Manitoba, listed
on the Western Ag web site at
www.westernag.ca.