Western Australia's northeastern Grain Belt, a medium to low rainfall zone we're
a two-year GRDC invested project led by The Liebe Group is helping growers to
make informed decisions about more efficient micronutrient use on cereals
in dry periods. A survey conducted by the grower driven research group indicated
most grain growers believed they had potentially yield limiting micronutrient
issues. So the survey was conducted in the 2018 season with over 100 paddocks
so we had a total of 400 sample points with 25 farm businesses from across the
northern agricultural region and that included plant sample surveys that were
conducted during the season on a number of wheat crops. From the survey we found
that most of all 90 percent of growers believed that they had issues with zinc
and copper that were limiting their crop potential. However the survey results
from 2018 actually only indicated some levels of deficiencies within zinc.
So you think we can see anything visual on the leaves at he moment Richard? For the
micronutrients would normally look for at the younger leaves these look quite
healthy. Dylan Hirsch is hosting the
demonstration site and says he was part of the 90 percent assuming micronutrient
deficiencies. I think it's fair to say that from our conversation with other
growers is is micronutrients are a complex subject and we're not as as
confident as what we'd like to be compared with other aspects of agronomy
and something we came to to better understand to in allocate our resources
better. Professor Richard Bell says severe deficiencies of the past are not
so likely now given many growers are applying micronutrients but The Libie
Group survey indicates deficiencies are not completely absent either. There still
is a percentage of crops that appear to be marginal or deficient so there's
still opportunities to use plant testing and soil testing strategically to try
and identify those sites where deficiencies might still exist. Over the
last five years we've started testing micronutrients in a
few ways. One is with our soil tests which are
indicative, give us indications of where soil micronutrients are at. But we've also
started to look at plant plant testing to get a better idea about how our
plants are taking those up and they've given us a few sites where we've got
some deficiencies with some of the micronutrients. So it's a balancing act,
Richard says there's also value in thinking about seed grain analysis. Grain
that has good micronutrient levels can be beneficial when sown on the soils
that might have marginal levels and there are a number of accredited labs
offering grain analysis for nutrient concentration. Growers could then consult
their advisors for an interpretation of the analysis.
Folia application can also be useful if you identify a deficiency during the season and that
enables you to rescue part of the yield that might have been lost otherwise. The
main message is that plant testing is the most effective tool that can be used
to monitor micronutrient status in crops and to then work with an agronomist who
is able to interpret that information for you to arrive at a better
micronutrient fertiliser program. Dylan says for him micronutrients are just
part of the potential yield constraints and hopes this research will deliver a
better understanding of nutrient management.
We are certainly keen to look
at the results of this project and will hopefully better allocate our resources
with their monitoring of micronutrients in our in our cereals because of it.
There's a couple of tools we use on farm, one of them is the we use agronomists on
site to look at visual signs and visual symptoms of micronutrient and other
deficiencies, the other one is GRDC has some really good guides on on how to how
to identify those particularly severe deficiencies that we use ourselves when
we respecting the crop. It's also about keeping our costs down and making sure
we're getting a bang for our buck where we were that buck