FARMERS have had record yielding crops in many regions across Australia, but a crop nutrition specialist warns that this would also mean they have taken out record levels of nitrogen (N) out of the soil.
Rob Norton, of the International Plant Nutrition Institute (IPNI) said a six tonne to the hectare wheat crop could have removed as much as 125 kilograms a hectare of nitrogen.
"The cupboard may be close to bare as we go into the sowing period," he said.
This will mean farmers enter the 2017 planting season with low levels of soil nitrogen that will need to be topped-up with nitrogen fertiliser.
Dr Norton said the dynamic would mean a change to the normal rates of fertiliser application, recommending an increase to 15pc of total nitrogen budget to go on upfront nitrogen.
"Normally, the best return on investment is to spend more of your nitrogen budget in-crop, this year it may be the case that farmers need to spend a little more early in order to get the crop up and going."
It is not good news for growers who are watching the approaching season with caution due to chatter about a potential El Ni((xF1))ño event developing.
With this on the horizon many would prefer to get a feel for the season before spending money on fertiliser.
Dr Norton said the potential for very low nitrogen levels meant a soil test would be a sound investment.
"Soil tests are far from perfect, but it is still the best method to assess nutrient supply."
He said the big wet may have leached nutrients further into the profile, especially the more mobile elements such as nitrogen and sulphur.
"This also is in favour of putting more nitrogen out early as the crop roots may not be able to access that leached nitrogen early on."