Elizabeth Meier1, Julianne Lilley2, John Kirkegaard2, Jeremy Whish1, Therese McBeath3
1CSIRO Agriculture and Food, 306 Carmody Road, St Lucia Qld 4067, Australia, www.csiro.au, firstname.lastname@example.org
2CSIRO Agriculture and Food, GPO Box 1700, Canberra ACT 2601, Australia
3CSIRO Agriculture and Food, Waite Road, Urrbrae SA 5064, Australia
In rotations, canola can provide a disease break for cereals and a broader spectrum of herbicide options to reduce the risk of herbicide resistance in weeds. However, canola can have higher costs of production than cereal crops. We therefore sought to identify combinations of management practices that would maximise gross margins and reduce the risk of financial loss from growing canola. We simulated continuous canola management packages (combinations of in-season N fertiliser rate, cultivar choice, time of sowing) for 50-years. To compare practices identified for contrasting environments we report results from two locations with relatively high and low average annual rainfall at Breeza, NSW and Minnipa, SA, respectively. Management practices made little contribution to gross margins unless climate variability was accounted for so results are presented within a framework of a hypothetical, always-correct seasonal rainfall forecasts and sowing opportunities. Regionally specific packages of the most profitable practices for sowing single canola crops were identified that can be adopted as sowing opportunities arise. These packages broadly included: decreasing N fertiliser rate in lower rainfall deciles and/or as the growing season progressed; a change in choice of cultivar rate of development from slow to fast when sowing was delayed; and selection of a conventional or hybrid cultivar at Breeza. These findings were relevant despite the lact of perfect seasonal forecasts available for growers.