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.

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.

2019 - Frankland

2019 - Katanning