With the rains last week, many regions have good topsoil moisture plus three to four feet of subsurface moisture. That means crop nutrients, not moisture, could be the limiting factor for yield. With fertilizer prices back in line this year, fertilizing to match yield potential can be an effective way to maximize profitability. Applying all fertilizer at the time of seeding is recommended, especially in the Black and Thin Black Soil Zones.
Considering a split application? Chris Holzapfel, researcher at Indian Head Research Farm in Saskatchewan, has done some work on split fertilizer applications. In summary, he says because canola usually yields quite well in the Thin Black and Black Soil Zones year in and year out, growers in those zones are probably best to apply all their intended fertilizer at the time of seeding — even if current conditions aren’t ideal. What’s more, if it turns wet and you have to broadcast your top dress, it can reduce fertilizer efficiency. When current conditions are close to ideal — a warm moist seedbed and good subsoil moisture — growers may consider a higher fertilizer rate. It’s not too late to soil test if growers are unsure of soil nutrient reserves.