CEREAL crop yields are being adversely affected by the inefficient use of micronutrients, according to a grain grower survey conducted across 25 farm businesses in Western Australia's northern agricultural region.
The survey was a part of a broader Grains Research and Development Corporation investment, including a two-year project which aimed to identify the requirements for, and benefits of, micronutrient foliar application in medium-to-low rainfall areas.
The research project was led by the Liebe Group and while the number of growers surveyed was small, their concerns are shared by many growers nationwide.
Micronutrients haven't been the focus of as much research as macronutrients and even less is known about micronutrient application in low to medium rainfall zones.
Latham grower and research group member Dylan Hirsch said the purpose of the project was to provide growers with greater knowledge about micronutrient rates and application timing, so informed decisions can be made to improve cereal yields.
"With our operation, we haven't really considered micronutrients to be a priority, not because we don't think they're important, but because we don't understand them well enough to be able to adequately allocate resources where we need them," Mr Hirsch said.
"We have a bit of a knowledge gap and most farmers around us would agree, micronutrients is something we don't understand.
"What we wanted to know is how much we should be applying to address any perceived deficiencies and what sort of timing we should be responding to."
The first part of the project in 2018 focused on tissue testing, with a few high risk sites sampled, based on previous results.
Mr Hirsch said the group was surprised that locations were significantly zinc deficient.
"The next stage of the project in 2019 involved looking at how we can treat those deficiencies using foliar sprays at different crop times," he said.
"We hope that will help us make better decisions in the future by responding to these deficiencies before it's too late and understand what rates we need to use.
"Even if there are no perceived yield responses from the project, it will be interesting to see how the plants are responding to those foliar sprays to see what sort of levels are getting the plant tissues up to where the adequate results are."
However, it's not just yield penalty from micronutrient deficiencies which the project was trying to address, with the Liebe Group also looking at how to better allocate resources.
Mr Hirsch said they also looked at how to make sure they're applying micronutrients to the areas that need it, rather than simply putting a blanket application over the whole farm.
"On the farm we use some GRDC fact sheets which have some really good guides on identifying more severe deficiencies which we can identify by looking at leaf damage," he said.
"We also consult with our agronomists who are more experienced on these nutritional deficiencies, they help to guide us on where we should and shouldn't be using micronutrients."
As the 2019 season in Latham was poor, yield results were low and there was no significant difference between the different treatments.
