8 Cover story continued from page 6 higher (4.7 bushels/acre) than fall strip-till and P and K. He stresses, however, that if you have soils you are not comfortable strip-tilling in the spring (medium or lighter texture, good drainage), this difference in yield can be made up by including starter fertilizer on fall strips. In the treatments tested, the same total amount of fertilizer was applied, just at different times, so the total investment in fertilizer is the same. Breimer is cautious about spring strip-tilling or even freshening of the spring strips. “Perhaps on lighter soil, it is an approach that works, but my experience on medium and heavier soil types is that fall strip tillage is best followed by stale seedbed planting the following spring directly into the strips,” he says. In Rosser’s view, some growers will prefer to strip-till in the fall or spring and will also consider the value of starter fertilizer on their corn planter. “You have to look at whether the planter already has starter fertilizer capabilities or does this need to be added,” he explains. “And you have to look at what the expected benefit to starter fertilizer (soil test levels, etc.) will be — what are the logistical costs of running starter fertilizer relative to their perceived benefits?” On the subject of starter, Rosser’s common question is whether strip fertilizer can replace the need for it on the corn planter. From his study, he can say that moving a portion of fertilizer from fall strips to spring starter might be a slight yield benefit. “Growers would have to decide if the value of this practice ($16/acre at $5.00/bushel corn) covers the costs of investing in 2x2-inch starter fertilizer equipment if your planter is not already equipped and tendering starter fertilizer to the planter in the spring,” he says. “In our study, applying starter fertilizer on fall-fertilized strips did narrow the yield gap between fall and spring strip-till — spring strip and fertility was not significantly higheryielding than where fertilizer was split between fall strip and planter starter.” Reflecting on corn prices, Rosser notes that over the last year, they’ve been higher than $5 (though now trending down), so that would make splitting potentially more attractive than the cost-benefit analysis noted earlier. However, if a fertilizer placement and delivery system has to be purchased, growers have to factor in the current increased equipment prices into their decisions. Looking forward, Rosser says there are still a lot of questions on the strip-till fertility front, particularly how to safely apply larger amounts of fertilizer where crop injury could be a concern. He is currently working on a Grain Farmers of Ontario-funded project with Dr. John Lauzon at the University of Guelph, investigating crop safety and response for various fertilizer placements in-strip. This project is funded in part by the Canadian Agriculture Partnership (CAP), a five-year investment by Canada’s federal, provincial, and territorial governments.•
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