Cutting the ‘precision’ out of precision agriculture

Just like the old spinners, modern surface applicators do a good job of spreading your dollars around on the ground


Figuring out how to precisely place seed and fertilizer into the soil has been the focus of public researchers, industry and farmers for 30 years. That initiative has paid off.

The list of precision agriculture tools today includes a wide range of devices that place seed and fertilizer exactly where you want it in different soil conditions. Drills, air carts and variable rate controllers can do a phenomenal job of carrying out instructions from your prescription map, or even on-the-go if you have the very latest leading edge technology.

Some manufacturers have gone so far as to offer automatic placement control based on real-time sensors.

However, the time factor can override best management practices in fertilizer efficiency. Such is the case with the trend toward broadcasting fertilizer in the fall. Research shows that surface-applied nitrogen is not financially economical when it comes to fertilizer investments, not fertilizer-efficient and not environmentally prudent. It takes the “precision” out of precision agriculture.

Some studies have indicated that when all of the costs are considered and yield losses covered, some larger-scale operations will benefit financially from fall spreading application of the majority of the nitrogen. Yield advantages from earlier seeding dates due to compressed planting seasons that eliminate nitrogen fertilizer tendering during seeding have value, as fall deep-banding research has also shown.

In a phone interview, John Heard recalled what Cindy Grant said in her final presentation just before she retired. “She said the products narrow the gap between banding and broadcast, but they don’t close the gap. They can stop a lot of nitrogen loss, but none of them work on reducing immobilization by the microbes. You only stop immobilization when you place nitrogen into the soil. Below the surface.”

“People are trying surface broadcast this fall because of the nitrogen efficiency products now available. I’d get into trouble to say they were oversold, so maybe I’ll just say they’ve been overmarketed.”

While fall surface-applied nitrogen with efficiency products may spread the workload, it also spreads dollars around on the ground. He says growers should consider the extra cost of using the products. Plus there is still nitrogen loss and yield reduction. But, he acknowledges, it’s all about convenience.

“I’ve have come to realize that low nitrogen prices allow farmers to put logistics ahead of nitrogen efficiency. Broadcasting is easier. Less labour. Faster. But that’s certainly not how I’m counselling people to do things.”

This spring, Heard went out to visit some farmers who have spreaders, mostly new European machines they call precision spreaders. They did calibrations on nine different units, showing the spread patterns. He said there’s not much spread precision when the wind blows.

“You know, it’s pretty windy on the Prairies. But if the wind stays away, some of these new units will give us a uniform 110-foot spread. But it’s on the surface only.”

Heard says fertilizer efficiency doesn’t seem to be important to prairie farmers. He says that when he travels to conferences and ag events in the United States, everyone expresses concern about fertilizer efficiency and how it impacts their margins. Heard says he’s surprised he doesn’t hear that concern from Canadian farmers.

“Is our Canadian dollar buffering us so much that we can ignore efficiency? Every year, Manitoba farmers spend $600 to $700 million dollars on fertilizer. It’s the fuel that drives our crops. So why are we not taking it more seriously?

“I saw a bunch of producers out surface applying today. I just hope they incorporate right away, and they’re prepared to top up if we happen to get a wet winter and a wet spring.

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