Soil and Crops

Farmers have been quick to add more nitrogen to increase the protein content in their wheat. In a new marketing era, farmers will grow what customers want

In 1968 as a young upstart at the University of Saskatchewan I attended a conference at the Agriculture and Agri-Food Canada (AAFC) Research Station at Swift Current. The topic was protein grading of wheat. The focus of the conference was to plan the research needed to be able to tell farmers how to best grow high protein wheat, in case protein grading came to pass.

My contribution to the meeting was this: “The research has already been done. When farmers get paid for protein, they can pork on the nitrogen (N) to make sure the protein is high.”

I had read the literature (two key references are provided at the end for P.Ag and CCA types that may wish to look them up). My comments were politely dismissed but in private a few research folks agreed with me.

Add more nitrogen

In the interim, protein grading came to pass and farmers quickly treated wheat differently than other crops. Pork on the N — if you do not get a return in yield you’ll get it in protein and either way you get paid.

For my 2010 crop, early rains leached the N but the crop rooted and took it up later. N taken up late goes to protein not yield. So I got 37 bushels per acre of No. 2 wheat with 15 per cent protein, which netted above $9 per bushel.

In years gone by, Western Canadian wheat protein was determined mostly by the weather — in wet years protein was low, and in dry years protein was high. Saskatchewan was always the runaway winner for protein and Manitoba was the lowest.

But in the 1970s, Manitoba started porking on the N and began growing the highest protein wheat. In 2011, wheat in Manitoba averaged 13.6 per cent protein, Saskatchewan 12.9 per cent and Alberta 12.5 per cent.

It is now interesting to ponder — have we reached the stage where we’re applying too much N? Creating a high protein quantity but not a high protein quality?

I recently came across an interesting piece of information from ages ago at the famous Rothamsted Research Farm, Harpenden, UK: “High nitrogen (protein) is generally associated with good quality wheat, yet the flour made from the grain of the plots… which received the highest … N, gives rise to such a loose, unstable dough that it can hardly be formed into anything resembling a loaf.”

That quote is from a book by A. Daniel Hall, 1910, Fertilizers and Manures. The data described came from 1903 plots that received up to 129 pounds per acre of N fertilizer and other plots with about 200 lbs. N per acre as manure.

As an undergraduate student I was exposed to some of the data from Rothamsted but when I looked at N rates greater than 100 lbs. per acre per year, I dismissed it as having no relevance to Western Canada. I now realize that principles of science are universal — how we apply them is local but the principles are the same.

In experimental work in Western Canada, it is becoming increasingly difficult to reproduce the huge yield increase to N that we saw in the early days of soil testing.

Another interesting quote from A. Daniel Hall: “The intensive farmer often becomes wasteful because, after his land is in good heart, he continues to add fertilizers at the same rate as he did when he was building up its condition.” Maybe we have reached the stage where we can back off N rates — particularly on good black soils with lots of organic matter and with the zero-till farming that is now the norm.

Some recent studies have also showed that sulphur fertilization plays a role in wheat quality even when it does not affect the yield. When the market recognizes that in price, perhaps we will be applying sulphur even though it may not increase yield.

Falling number

In the past, a simple measure of the protein content of wheat was a good indicator of what the loaf of bread made from it would look like. Now, that is not always the case.

We’re hearing more about falling number. Falling number is a measure that will predict what the baked loaf will look like. It can be increased or decreased by N fertilizer. Sprouting is a big factor in lowering falling number.

The discussion about elevator testing of falling number is where protein testing was 30 years ago.

So, there you have it — something to think about as we enter a new era in wheat marketing in Western Canada. †

  •  Fernandez and Laird, 1959. Yield and protein content of wheat in Central Mexico as affected by available soil moisture and nitrogen fertilization. Agronomy Journal Vol 51 pages 33-36.
  •  Finney et al. 1957. Effect of foliar spraying of Pawnee wheat with urea solutions on yield, protein content, and protein quality. Agonomy Journal Volume 49 pages 341-347. †

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