All farmers want to get their crops off to a good start, and the right amount of phosphate gives canola that pop-up effect that farmers just love to see. There is, however, such thing as too much of a good thing.

It turns out that although much research has been done on safe rates of nitrogen fertilizers based on seedbed utilization in canola, not as much work has been done to understand the effect of phosphate fertilizers on canola seedlings.

In this episode of the Canola School filmed at CanolaPalooza near Saskatoon, we talk to Patrick Mooleki, of Agriculture and Agri-Food Canada, about his current research that’s working to understand these interactions more fully.

Farmers understand ammonia toxicity and try not to harm their seedlings with nitrogen based fertilizers, but there is also such thing as salt toxicity that needs to be considered. Monoammonium phosphate and other fertilizers can cause salt toxicity by dehydrating the seed. Mooleki says “That means it is going to absorb moisture away from the seed so the seed is not going to germinate very well.”


There are already guidelines for in-row phosphate placement but these are based on one-inch opener width and 9-inch row spacing only. For urea, there are charts with one-, two-, or three-inch openers and of row spacings of six-, nine-, and 12-inches. Mooleki says they hope to generate enough information to create similar charts for phosphorous.

Related: Canola School: Fertilizer toxicity may cause seedling death in dry conditions

One thought on “Canola School: Dialling in seedbed-safe rates for phosphate

  1. For some very interesting data on seed places phosphorus, check out the Bourgault agronomy trials on their website.

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