Think twice before cutting back on fertilizer rates this spring.
“With canola prices having backed off of last spring’s highs and fertilizer prices remaining relatively high, growers might be tempted to shave fertilizer rates in order to reduce costs,” says Canola Council of Canada senior agronomy specialist John Mayko. “But canola growers who cut fertilizer rates may end up cutting their profits.”
With higher-than-average canola prices, the opportunity for good returns is solid; however, growers will need to use generous rates of nitrogen to achieve optimum net returns. Nutrients such as phosphorus and sulphur will also need to be at adequate levels to optimize yields.
“Today’s hybrids need adequate nitrogen to optimize the yield potential of the hybrid genetics,” says Mayko. “Although it is important to pencil out the potential profit situation for each farm, consider this: With canola at $9/bu. and nitrogen costing approximately 60 cents per pound, for every 10 lbs. of nitrogen applied, it will only take a three-quarter-bushel gain per acre to recover that
cost. Any yield above this gain is profit.”
Research conducted by Agriculture and Agri-Food Canada and Westco Fertilizer indicates improved nitrogen response curves for hybrid varieties compared to open-pollinated varieties. That means for
a given rate of nitrogen, hybrids typically yield better than open-pollinated varieties. However, to achieve the full genetic potential of current hybrid varieties, greater amounts of nitrogen fertilizer are required.
With phosphorus (P) fertilizer prices remaining high, growers
might be considering cutting back. However, P rates must be adequate to ensure proper early-season plant development in canola. If growers have been applying moderate to high rates of P in recent years, an option to consider is replacing some of this year’s P fertilizer with JumpStart seed inoculant.
Growers with low-to medium-P levels in their soil should apply at least 15 to 20 lbs./ac. of seed-placed or side-banded phosphate. This is important, especially in early-seeding situations, when soils are often cool.
Sulphur (S) rates also need to be adequate across all areas of the field. Because of the inherent variability of S in many fields, an application of 15 to 20 lbs./ac. of S as ammonium sulphate is recommended, especially if S is only applied to a rotation in the canola year.
Soil testing is the only way to truly evaluate the nutrient status of a field and should be considered as a tool for making the right decision on applying fertilizer this spring.