Can wheat compete?
Wheat and other small grains, once a staple in the crop rotations on upper Midwest farms, are losing their spot due to market forces and biotechnologies that favor other crops.
“Oat acreage is at the lowest in recorded history, and wheat is not far behind,” says Jochum Wiersma, a small grains specialist with the University of Minnesota. “If we're going to maintain any wheat acreage, we will need to maximize grain yield and push the limits.”
Wheat does have good value as a rotation crop and for spreading out planting and harvest seasons. And, says Wiersma, wheat breeders and farmers have made great strides at improving wheat yields.
“Since 1995, yields in northwest Minnesota have gone up an average of 1.6 bushels per acre per year. On a percentage basis, that's as good or better than corn!” he exclaims.
To make wheat competitive, Wiersma says you have to select varieties with high yield potential, plant them as early as possible, and manage for maximum grain yield. You also need to produce 14% protein in the grain.
Following are his ideas for achieving those goals.
This practice of applying nitrogen late in the growing season originated in Europe about 40 years ago. It's used on bread-grade wheat to boost the protein level into premium ranges.
“Pre-plant nitrogen is the best way to maximize grain yield. But late-season nitrogen is how you can improve grain protein content,” says Wiersma.
The most common way to do this is by applying 10 gallons of liquid urea ammonium nitrate (UAN) with an equal amount of water as a foliar application just after anthesis, says Wiersma. Dry sources of fertilizer like urea or ammonium nitrate, commonly used in Europe, haven't been effective in the U.S. The shorter grain-fill period and lower rate of precipitation don't give the crop opportunity to take up the additional nitrogen through the soil.
“We get anywhere from a .5% to 1% higher protein in the grain at harvest this way,” says Wiersma. “Do not expect all fields to respond equally well. Research has not been able to identify which varieties respond best to the foliar nitrogen. Differences can be attributed to the conditions during and immediately following application, but they don't explain all the variation we observe.
“We do know that the best time to apply is in the evening hours; the worst time is in the heat of the day with the sun glaring and the winds blowing,” he says.
Unfortunately, there are no in-season predictors to tell you when it makes economic sense to use UAN to boost protein.
“Increasing grain protein from 11% to 12% often still means substantial discounts at market. Bringing protein from 13% up to around 14% allows you to avoid discounts as high as $1 per bushel,” he says.
Leaf rust is one of the most significant fungal diseases of wheat, and it's common in upper Midwest fields. Even a 5% severity at anthesis on the flag leaf and penultimate leaf will produce economic yield losses,. More serious infestations will reduce yields by 50%. The reddish-brown spores the fungus produces in large quantities can mean that “you have a red combine, even if you bought a green one,” quips Wiersma.