Canola School: Strategic fertilizer use requires attention to all 4Rs


Agronomic strategies that maximize fertilizer efficiency should be good for a farm’s financial bottom line and the environment, but specific decisions about how fertilizer is applied should be made with the overall outcome in mind, stresses Marla Riekman, soil management specialist with Manitoba Agriculture.

The 4Rs — the right source at the right rate, right time, and right place — are commonly used as a framework for how to think about and improve fertilizer application.

A change in any of those four variables must account for what’s happening with the others, as there can be tradeoffs, explains Riekman, in this Canola School episode.

For example, the use of a urease inhibitor on urea can reduce nitrogen losses under the “right source” column, but if adopting this recommended management practice coincides with a shift to broadcasting on the soil surface rather than banding it into the ground, any economic or environmental gain could be more than offset in the “right place” column.

“We often talk about the fact that to be the most efficient or the most effective, we need to have good agronomy, good economics, and good environmental planning all working together. Because if it is one benefiting one, it should benefit the rest of them,” she says.

Having flexibility to adapt to different scenarios with fertilizer placement requires forethought when purchasing and setting up seeding and fertilizer application equipment, notes Riekman. “It’s a really important thing we need to remember the agronomic plan of the farm and what the farm’s capabilities are when we’re making those decisions for equipment.”

Check out this Canola School episode for more with Marla Riekman on fertilizer efficiency, 4R implementation, and the intersection between good agronomy, economics, and environmental sustainability, filmed at the Manitoba Crop Diagnostic School in Carman, Manitoba:

Related Canola School episode: Second-guessing that “safe” rate of seed-placed fertilizer

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