Winter Wheat May Need Top-dressing

Some winter wheat may have been fertilized conservatively with nitrogen last fall with the intent that fertilization would be completed this spring.

“Top-dressing winter wheat is best done using 28-0-0 (UAN) solutions using stream bars to avoid significant leaf burning,” says Dave Franzen, North Dakota State University Extension Service soil science specialist. “Do not broadcast spray with UAN. Urea also can be spread, but if the forecast is not almost 100 percent sure of significant rain within a couple of days of applying, having the retailer impregnate the urea with Agrotain would be a good plan.”

When the early spring season is wet, the yield potential for winter wheat increases. In much of the state, there is potential on productive soils for 80 bushels per acre or more.

“To get to that 80 bushels per acre, about 150 to 180 pounds of nitrogen per acre would be required,” Franzen says. “To get to that number of pounds, take the total of the fall soil test nitrogen report, any previous crop nitrogen credits and any fall-applied nitrogen. The remaining amount of nitrogen needed will need to be applied now.”

On sandy soils that are low in organic matter, the addition of about 10 pounds of sulfur per acre using products, such as ammonium sulfate or gypsum, but not elemental sulfur, may be needed, considering the amount of rain that fell last fall.

“Top-dressing should begin as soon as practical,” Franzen says. “However, practical means driving through the field without making a muddy mess of the soil or making ruts.”

NDSU Agriculture Communication