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TECH@
WORK
Oldtech, newrules
Variable-rate application
and farming practices have been an
emerging technology for 20 years—an
oxymoron to be sure. The technology
works, but we still have much to learn
about how to best utilize it.
Flash back to 1997: After watching an
episode of
Seinfeld
, checking your fax
machine in-tray and firing up your IBM
PS/2 Model 56SX desktop computer, you
pull up the impressive multi-coloured
yield maps created using your fancy new
GPS-enabled yield monitor. The hot topic
in crop production circles is the huge vari-
ation revealed by GPS yield maps and how
the obvious next step in progressive crop
production practices will be to vary ferti-
lizer, seeding rate and other treatments to
match the variation in productivity across
fields. It was a bona fide no-brainer.
Fast forward to 2017: After 20 years,
adoption of variable-rate cropping systems
is nowhere near where we thought it
would be. What happened?
It’s definitely not a technology problem.
Almost from day one we have had the
ability to use GPS-driven prescriptions to
control clutches, sprayer rate controllers
and hydraulic drives more effectively.
Most new equipment comes with the
ability to vary rates. The challenge for
variable-rate farming has not been about
accurate application technology—that’s
the easy part. The hard part is creat-
ing the right rate prescription for each
field, finding the low-hanging fruit, and
measuring variable-rate results to know
definitively whether that prescription is
winning or losing.
It’s a classic case of the hardware
and software being available before the
required agronomy advances. If we could
wave a magic wand, we would remove
variability—having consistent topogra-
phy, soil type, drainage and fertility is
The science andartof variable-rate farming
a farmer’s dream, but not the reality for
most producers. So, to address variations
in productivity, variable-rate technology
actually adds another level of variability
by treating low-yielding areas differently
than high-yielding zones. The logic is
sound, and I’m convinced we will get bet-
ter and better at this, but 20 years ago we
thought it would be as simple as collecting
data, passing it to our agronomist to gen-
erate an iron-clad prescription, and away
we go with variable-rate fertility, seeding
and spraying.
The reality has been that variable-rate
farming requires an extremely high level
of knowledge of each field. This can be
gathered via yield monitors, soil testing,
aerial photos and infrared maps from
drones, planes or satellites, and topogra-
phy and soil maps. You can use as many
layers or resources as you like, but the
objective is to identify simple production
zones within each field to separate low-,
medium- and high-yielding areas. It takes
more than one year’s yield data, and this
is where your intuitive knowledge of each
field becomes invaluable.
Despite our ability to generate and
access all sorts of data, veteran precision
agriculture specialists say that sometimes
the best and most accurate “starting
point” production zone maps they see are
hand drawn by the producer. They also say
that if you as a grower receive a prescrip-
Photo: iStockPhoto
Variable-rate technology is far from new, but the agriculture industry is still trying to find the best ways to put it to
work for farmers.
Spring
2017
Grains
West
44