While seasonal conditions have limited yield prospects across a lot of the state, five canola trials in the south are testing the economics of using much higher than district rates (>160-200N). High yielding crops demand a lot of nitrogen (N), and where soil reserves are declining, they will be responsive to higher rates – especially if they have the potential.

The trials are at Williams, Katanning, Boyup Brook, Frankland and Munglinup, and for all of them, it’s been a long time since they’ve grown a productive legume crop or pasture. All trials are showing excellent yield potential but without high rates of N fertiliser, it’s unlikely their potential will be realised. 

This year’s trials feature high rates of Flexi-N banded, with comparisons against post seeding applications and splits, with treatments well into flowering.

Canola yield table

Table 1. Responses to Flexi-N on full flowering canola at Darkin in 2013

The responses to the late Flexi-N applications will be interesting. A CSBP trial in Darkan in 2013 showed that Flexi-N could still be very profitable at full flowering (Table 1). The site had already had 87N applied earlier in the season, and interestingly there was relatively little effect on oil.

If we need 80N to grow a 2 t crop, we need 130N to grow 2.5 t, and 180N for 3 t/ha – but of course we to have that potential, and it has to be profitable.
The harvest data and economics will be interesting.


2019 Frankland canola trial2019 - Frankland

2019 Katanning

2019 - Katanning

James Easton
By James Easton
- Senior Agronomist

James has over 30 years’ experience working on soil and plant nutrition (crops and pastures).

He graduated from the University of Western Australia with a degree in Agricultural Science (Honours). He has in depth knowledge of historic fertiliser research trials and has worked closely with many growers, consultants, research institutions and farming groups over the years.

James gets a lot of satisfaction from sharing his knowledge with growers and those who support them. And he enjoys the fact that we are always learning.

Agronomic insights

Want to stay up to date? Have our latest research findings and news delivered to your inbox