High on canola's preferred menu are minerals, such as potassium and boron, but the old favourite, nitrogen, remains critical to successful crops, according to GRDC supported research.

Department of Agriculture and Food researcher Ross Brennan said that although responses to applied potassium and sulphur were substantial, all results were regulated by nitrogen.

Mr Brennan explained that nitrogen was applied as urea and potassium as muriate of potash, with grain yields measured in early December, when dried shoots were also examined to gauge in-plant concentrations of the target nutrients.

"Nitrogen is a key to unlocking canola's potential and when no nitrogen was applied, potassium made no impact on grain yield, irrespective of how much was heaped on," Mr Brennan said.

"However, in half the trial plots, nitrogen failed to generate a response without potassium."

GRDC Manager, Agronomy, Soils and Environment, Martin Blumenthal reminded canola growers to always check soil pH.

"If soils are too acidic, canola's response to anything else will be very limited," Dr Blumenthal noted.