Dry years obviously reduce yield potential and demand for nitrogen (N) fertiliser but crops will respond if soils are deficient enough and the N strategy is effective.
This year two trials near Binnu and Carnamah showed that banding higher rates of Flexi-N at seeding could be very profitable in a dry year, and more effective than late tillering/early stem elongation applications.
At both sites, the growing season rainfall was about 150mm with most of it falling within a month of the break of the season (June 6). Both sites had a long cropping, no legumes for many years, and soil N reserves had been run down by some above-average crops.
At Binnu, banding 100 L/ha Flexi-N increased yields from 0.4 to 0.7 t/ha. There was no response to applying 100 L/ha Flexi-N at early stem elongation on 8 August.
At Carnamah, banding 100 L/ha Flexi-N increased yields from 1.0 to 1.4 t/ha. The response to applying it on 6 August was only 0.2 t/ha.
At both sites, banding Flexi-N was effective and profitable. Applying N at early stem elongation was not effective and not profitable - there wasn’t the follow-up rain to make it effective.
‘Playing the Season’ can be risky without follow-up rain.
These trials showed that the risk of financial losses could be reduced by banding N at seeding.
These trials showed that, in a low rainfall environment, banding as much as 100 L/ha Flexi-N could be more profitable than playing the season.
Wheat grain yields and economics from CSBP trials at Binnu and Carnamah.