As wheat yields go up, protein levels tend to go down. That’s a well-known fact, but is there is anything you can do to have both?
The answer is a qualified yes, but whether farmers can “push” protein content remains a subject of much debate.
The only option for achieving higher protein and milling quality is to increase nitrogen (N). Nitrogen comprises about 17 per cent of protein, and so it is the nutrient with the greatest effect on protein content.
Target yields for wheat (or any other crop for that matter) are usually determined by reviewing planting conditions and then providing enough nitrogen to try to achieve the target. Farmers always seek maximum yield and will fertilize accordingly, says John Heard, a crop nutrition specialist with Manitoba Agriculture, Food and Rural Initiatives.
“Yield is the focus,” he says. “By fertilizing for full yield potential at seeding you get both yield and protein.”
THE TROUBLE WITH PROTEIN
But protein alone is a little trickier. In some years, farmers may be tempted to over-apply nitrogen at the start to try and push protein levels, but that can be risky if growing conditions prove less than favour-able, in which case both yield and protein levels suffer. N is highly mobile in soil, so, especially in wet conditions, a lot of that additional nutrient could leach out and not benefit the crop at all. There are times when it simply doesn’t make economic sense to try and chase higher protein levels, especially if premiums are low and input costs are high.
“It’s really hard to target the high protein,” says Art Enns, who farms in the Red River Valley near Morris, Man. “If there’s something to be gained for it, I’ll try harder, but because the premium (for milling quality) fluctuates so much and it’s just one small increment of the overall thing anyway, I’d sooner target towards yield and forget about the protein.”
Supply and demand, as with any commodity, greatly influences the price being offered for wheat that meets the 14 per cent protein requirement for milling. This year, that premium has edged up significantly because of some disastrous weather conditions across major wheat growing areas of the world (including Canada) that have caused both yield and quality concerns. In January, the Canadian Wheat Board failed to fill a wheat tender from Japan because its wheat had a lower than acceptable protein level.
SPLIT APPLICAT IONS?
It’s almost impossible to predict if market and growing conditions will all come together, especially in fall or spring when it’s time to apply nitrogen for the next crop. As a result, some farmers have experimented with split applications of N, or rather, they have applied the usual amount before or at seeding, but added additional N later in the season if it looks like the conditions are supportive of a higher protein content.
Enns has dabbled with later N applications on his wheat crops over the years, but isn’t convinced it’s worthwhile.
“I’ve had some very inconsistent results over here with it,” says Enns. “First of all, the applications don’t always work. Take this year as an example. I did a few different tests, where I did two or three applications of nitrogen in stages, and I had absolutely no results. In fact, I ended up with some of the lowest protein I’ve ever had on my farm and I contribute a lot of that to the growing season we had, with high moisture, where the nitrogen was probably leached down because of all the rainfall.”
And it’s still a gamble when it comes to getting paid for that extra effort, says Enns.
“I have been able to raise protein levels, yes, but they’ve been so minor, that in most cases it’s covered the cost of the nitrogen, but it hasn’t really put much extra in there,” says Enns. “So the experience I’ve had with it is that it’s hardly worth it.”
Enns says he’d rather focus on getting the biggest bang for his input buck.
“As a farmer, I am more worried about disease in my wheat, the fusarium levels and stuff like that, than protein, because that’ll downgrade me even more,” he says. “Although protein is an issue and this year it would have been nice to have the higher protein, most of the time that isn’t the case. So I’ll spend the $20 on fungicides and try to get the get an extra five to 10 bushels an acre that way, so I increase my net returns, rather than spending it on protein, which has not proven itself. Not on my farm anyway.”
WHAT THE RESEARCH SAYS
Although there may well be some growing areas where a late N application could yield better results in terms of increasing wheat protein levels, much of the scientific research on the subject to date has supported the experience of farmers like Enns.
Cynthia Grant, a soil scientist at AAFC’s Brandon Research Centre, followed four years of field studies throughout Manitoba and Saskatchewan. In a paper released a few years ago, she concluded: “Balancing N supply with yield potential can optimize both crop yield and protein content. Selection of an effective combination of nitrogen source, placement and timing can improve fertilizer use efficiency. In-crop nitrogen applications can increase protein content, but are not a substitute for adequate levels of N applied prior to or at seeding. Careful management can improve both the protein content of wheat and the economics of crop production.”
Achieving high yield and protein in wheat is a double bonus. But depending on the year, you might just have to settle for one or the other.