High-Yield Wheat: A Contrast
in Climate and Management Systems

When people refer to high-yield or intensive wheat production systems, they are most often referring to European winter wheat production, explains Dave Franzen, soil specialist with the NDSU Extension Service. “In Europe, rainfall is generally not limiting to winter wheat production. Rain falls frequently, temperatures are mild, rarely pproaching 90 degrees in the summer, and temperatures are only moderately cold in the winter, so wheat production potential is usually very high.”

Franzen notes that the differences between spring and winter wheat are significant. “With winter wheat, the seeds are planted in the autumn, when soil temperatures are cooling and the amount of sunlight is decreasing. There are usually five to seven months between planting and head differentiation,” he explains.

“In areas with lots of over-winter precipitation, there is ample opportunity for pre-plant nitrogen to be lost from the soil. Consequently, little nitrogen is applied at planting time, and the bulk of nitrogen applications are made when the plants begin to grow actively again in the spring, often as two or three split applications. The cool, moist conditions of northern Europe are also conducive to diseases, so multiple fungicide applications are made,” Franzen says.

By contrast, spring wheat in North Dakota is planted when soil temperatures are cool and warming up, and the amount of sunlight is increasing. The period between seeding and head differentiation is perhaps seven weeks, not seven months. In most years, the risk of nitrogen loss from the soil between planting and head differentiation is low. So it makes sense to have nitrogen available at the beginning of the season to maximize per-plant production potential, Franzen says.

Some high-yield wheat management programs insist that high rates of seed be planted, sometimes up to three bushels per acre, to eliminate tillering, which is seen as detrimental to high yield potential. “This is not how high-yield wheat is produced in Europe,” says Jay Goos, NDSU soil scientist. “Winter wheat is most typically planted at 150 seeds per square meter in England, or about 50 pounds of seed per acre. Tillering is critically important to achieving high yields in Europe.”

Some programs also insist that no nitrogen be applied preplant or at seeding in order to reduce tillering, because only the main stem is significant in producing yield in North Dakota. “We have studied the contribution of the main stem and tillers to final yield in North Dakota, and we know that this is not true,” says Goos. “Tillers do contribute significantly to yields here.”

The notion that only the main stem is most important to final grain yield is true under only two conditions:

•  When there is such severe drought that the tillers abort, usually in July. Yields of 15-25 bushels per acre usually result. 

•  When plants are so sick in the early stages of growth that they refuse to tiller. Severe nitrogen and phosphorus deficiency are the two most common causes of this problem.

“Spring wheat plants that refuse to tiller are abnormal and truly sick,” Goos says. “Nitrogen deficiency severe enough to inhibit tillering will also inhibit adventitious root formation. Research in North Dakota has shown about a 3-to-1 ratio of adventitious roots to tillers. Fewer tillers above the soil means fewer roots below. Adventitious roots and tillers come from the same plane on the main stem. Any stress that inhibits tillering also inhibits root initiation.”

If the severe nitrogen deficiency continues until the five- to six-leaf stage, reduced head size will result.  Sometimes, severe early-season nitrogen deficiency will cause plants to produce fewer leaves on the main stem, producing seven-leaf instead of normal eight-leaf plants, Goos says.

Seven-leaf plants invariably have a much smaller head size than eight-leaf plants, Goos says. In North Dakota studies, the main stem accounts for less than half of final grain yield at yield levels greater than 45 bushels per acre. However, not all tiller positions are equally productive. The T1 and T2 tillers often produce heads almost as big as the main stem head, and they are closely synchronized with the maturity of the main stem. Later tillers, however, are not synchronized with the main stem and often form nuisance “green heads” at swathing time.

“In the European high-yield wheat systems, tramlines are used to support the frequent trips across the fields,” Franzen notes. “Those tramlines are used on farms that are significantly smaller than those in this region.” Using the tramlines, multiple applications of nitrogen are made, either broadcast granular fertilizer or as surface-banded liquid fertilizer. Rain will usually fall within 48 hours, so nitrogen efficiency is relatively high and losses are low.

Very high rates of nitrogen are used, with 200 pounds per acre common. Growth regulators are used to shorten straw and strengthen stems. Fungicides are used for disease prevention. “With all of these inputs and a very favorable climate, high yields of wheat are common in northern Europe,” Franzen says.

So why hasn’t North Dakota State University been recommending European-style production systems for wheat?

“First, spring wheat isn’t winter wheat. Second, we have a semi-arid climate. Heat and drought stress can reduce potential head size in June and can cause tiller abortion in July. Also, late-season stress can lead to small, shriveled seed. We promote early planting and water conservation to try to minimize these losses, but often these stresses cannot be avoided,” Franzen says.

“Delaying all nitrogen input until after the crop is done tillering is risky in North Dakota,” Goos explains further. “Tillering and root formation will be reduced if there is an early-season nitrogen deficiency. In some years, weather in June is warm and dry, meaning top-dressed nitrogen will not move into the soil until a major rainfall event. In other years, a big dump of rainfall could prevent nitrogen topdressing for a week or more.”

“Also, few farmers or fertilizer dealers have the time or equipment to apply all of the nitrogen to all their wheat fields within a very narrow application window when other operations, such as spraying for weed control, are competing for time,” Franzen says.

“We have seen very high wheat yields without using the European method,” Franzen says. “The recipe is simple: Start with a high soil P test or a medium soil test plus starter phosphate. Apply nitrogen before planting to support a yield about 30% higher than average, giving credit to soil nitrate and legumes through soil testing. Pay attention to seeding rate and planter calibration, weed control, insects and disease control.”

No matter where you farm in North Dakota, the early-season targets for a high yield potential are the same, Goos says. They are:

•  One million healthy plants established per acre.

•  A “white zone” length of about an inch. The “white zone” is the length between the seed piece and the chlorophyll line. This is determined after the plants have emerged and is a measure of effective seeding depth after the soil has settled. The deeper the seeding, the longer the “white zone,” which puts a stress on the early plants, resulting in reduced early vigor and tillering.

•  At least a 90% initiation of T1 and T2 tillers. Less than 90% initiation of T1 and T2 tillers is usually the result of less than optimum nitrogen and P fertility, or seedbed problems.

According to Franzen and Goos, the yield potential of wheat if farmers achieve those early season targets is enormous. It would result in one million main stems per acre producing 30 seeds each, and one million T1 and T2 tillers producing 20 seeds each, at 35 milligrams per seed equaling 90 bushels per acre, far greater than current production levels for most area wheat farmers. Obstacles to achieving this level of production include rainfall, temperature extremes, insects, disease, nutrient deficiency and lack of weed control.

“A production system that utilizes very heavy seeding rates and delayed, multiple nitrogen applications is a prescription for disaster for malting barley,” Goos notes. “Thin, high-protein barley is more likely with such a system.”

“Growers should be aware of the pitfalls of using a European-style system here. If we lived in Europe, we would use that system. But we live here and have seen the environmental extremes that are not only possible, but likely,” Franzen says. “The Great Plains climate is a risky climate. Cropping systems need to be used that reduce risk, not increase it.”

Opti-Crop Intensive Wheat Management Steps Online

Much of the recent attention to intensive wheat management is because of Opti-Crop and Miles Enterprises, which successfully introduced the concept in Kentucky.

In 1986, Billy Joe Miles, owner of Miles Enterprises in Owensboro, Ky., led a delegation of Kentucky grain producers on an international tour of wheat farms in the United Kingdom. The group saw that European growers were reaping wheat yields three times greater than those typically harvested in most U.S. wheat-producing regions.

Miles returned home and launched a fee-based intensive wheat management program built upon the European techniques. Many Kentucky farmers successfully implemented the innovative system.  In the 15-year span since the program started, Kentucky’s wheat yield average has doubled, while yields in most surrounding states have remained stagnant.

Opti-Crop held meetings on intensive wheat management in North Dakota earlier this winter. Production management steps included in the plan are outlined on the company’s web site, www. milesnmore.com/farmsupply/wheatmanagement.html .