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BY PETER GREDIG
tion map from your agronomist that does
not match your knowledge and experience
of the field, do not follow it blindly. Simply
starting with two or three zones per field
is highly recommended.
In the past, adopting a variable-rate
strategy for seeding or fertility required
a leap of faith. It was difficult to measure
the performance of variable-rate systems
versus the traditional single rate. Today,
variable-rate prescription software can
create blocks within each zone to apply
your standard seeding or fertilizer rates.
This helps assess the performance of the
variable-rate program versus a standard
single rate.
Interestingly, precision agriculture
experts I’ve talked to say that the most
proven and dependable return on invest-
ment for variable rate is actually found in
GPS-enabled automatic on/off technology
to avoid overlap and double application.
You have to crunch the numbers on
costs for the equipment over the acres
you cover, but whether you go with auto
shut-off clutches/switches for each seeding
row unit or sprayer nozzle, or sectional
controls to make it a bit more affordable,
you are saving seed and input costs every
time you eliminate double coverage. Expe-
rience has also shown that there are yield
benefits as well, especially on seeding,
where doubling up generally results in
yield reduction.
The bottom line is that equipment and
software available off the shelf make it
quite easy to vary seeding and fertilizer
application rates. But to really make it
work requires effort to accurately identify
production zones, determine which input
is the best candidate for variable-rate
payback for each crop, and commit to
continually assessing and tweaking the
prescriptions by analyzing data. Varia-
ble-rate farming is a management-driven
process—not exactly the easy-peasy
data-dump-and-go deal we envisioned 20
years ago.
Peter Gredig is a corn, soybean and wheat
producer near St. Thomas, ON. He is also
a partner in AgNition Inc., a Guelph-based
mobile development company focused on
building agriculture apps and solutions.
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@BeSeedSmart
Did you know?
A seed test is the best way to
predict seed performance.