Canola Digest, January 2013 - SaskCanola

LEVERAGING RESEARCH
HOW DO INPUTS
ADD UP?
By Heidi Dancho
A recent study proves the importance of
optimizing fertilizer, herbicides and genetics
to produce high and stable yields.
hen canola is properly
managed, yield improving inputs – like
better genetics, fertility and herbicides,
are additive; they build on each other to
improve yield,” says Eric Johnson, weed
biologist with Agriculture and Agri-Food
Canada (AAFC) in Scott, Saskatchewan.
“The result is that by combining them,
we produce even higher yields,” confirms
Stewart Brandt, former AAFC researcher
and current research manager with
the Northeast Agricultural Research
Foundation in Melfort, Saskatchewan.
With funding through the Prairie Canola
Agronomic Research Program, Johnson
and Brandt led a four year canola-barley
cropping sequence study to determine
the effect of adding and removing inputs
to both empty and full input systems.
Researchers examined the impact of
full and 50 percent rates of fertilizer,
herbicide and seed, as well as removing
fertilizer and herbicide completely,
and replacing a hybrid with an open
pollinated variety.
“When canola is properly
managed, yield improving
inputs are additive;
they build on each other
to improve yield.”
– Eric Johnson
Canola input study at Scott, Saskatchewan shows the difference between the full input
treatment plot (left) and empty input plot (right).
In addition to illustrating how inputs
build on each other to improve yield,
the study demonstrated the risk of input
reductions on canola yield and yield
variability over time.
FERTILIZER AND HERBICIDES
“The study showed that there is some
opportunity for perhaps reducing
fertilizer or herbicides inputs for one
year without a huge impact on yield,
but if you continue to do this, it definitely
increases your risk and greatly reduces
yields,” says Johnson.
For example, the study found that while
cutting fertilizer rate by 50 percent had
no effect on yield in year one, it resulted
in yield reductions of eight, 14 and
22 percent respectively in years two
to four. Removing fertilizer completely
resulted in yield reductions of 17, 23, 30
and 38 percent respectively. Eliminating
herbicides did not result in lower yields
in year one, however it severely reduced
yield in years two to four by 31, 60 and
76 percent respectively.
continued on page 14
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CANOLA DIGEST JANUARY 2013