Canola growers who cut their fertilizer rates with the high price of crop nutrients in mind may end up cutting their profits, the Canola Council of Canada warns.
With spring fertilizer prices at or close to record highs for most products, growers may be tempted to reduce fertilizer rates on their canola for this coming season, said John Mayko, senior agronomy specialist with the Canola Council of Canada at Mundare, Alta.
Higher-than-average canola prices mean growers will need to use generous rates of nitrogen to achieve optimum net returns, he said. As well, other nutrients such as phosphorus and sulphur must be at adequate levels to optimize yields.
And current hybrids need adequate nitrogen to make the most of the yield potential of their genetics, he said.
Research conducted by Agriculture and Agri-Food Canada and Westco Fertilizer indicates improved nitrogen response curves for hybrid varieties compared to open-pollinated varieties. This research shows that for a given rate of nitrogen, hybrids typically yield better than open-pollinated varieties, and at moderate nitrogen rates, the yield response curves for hybrids are steeper than open-pollinated varieties.
Mayko points out, however, that this same research shows if nitrogen rates are cut back, yield declines can be more pronounced on hybrids than open-pollinated types.
With phosphorus (P) fertilizer prices approaching $1,100 a tonne this spring, he says growers may be especially tempted to cut back on P rates. He warns, however, that phosphorus rates need to be adequate to allow for proper early season plant development.
If growers have been applying moderate to high rates of P to their crops in the past, Mayko suggested that replacing some of this year’s P fertilizer with a seed inoculant might be a worthwhile option to consider.
Sulphur rates also need to be adequate across all areas of the field. Because of the inherent variability of sulphur (S) within many fields, Mayko recommends an application of 15-20 pounds per acre of S as ammonium sulphate, especially if S is only applied when canola is planted in the rotation.
Growers should soil test this year to evaluate the nutrient status of their soil, he added. “Only then can you make the right decision of how much to apply.”
Growers also need to figure out the potential profit situation on their farm, but in general, he said, “with canola at $12/bu., and N costing approximately 60 cents/lb., for every 10 lbs. of N applied, it will only take half a bushel per acre of additional yield to recover that fertilizer cost, and any yield above that is pure profit.”