With hheat harvest progressing, it’s the right time to start thinking about next year’s fertilizer needs for winter wheat, says Gary Hergert, University of Nebraska fertility specialist. With adequate moisture in most of the wheat-producing areas across Nebraska and other parts of the country, yield potential for next year’s crop should be good, he says.
"Fertilizer and wheat prices have undergone major changes in the past couple years," Hergert says. "Adequate spring moisture has produced high yields in many parts of Nebraska, but with high fertilizer prices, many producers decreased nitrogen applications last year, resulting in lower protein content in some wheat.
"Now some elevators are paying premiums for higher protein content."
Hergert says wheat prices have rebounded some in the last few weeks, so no-tillers should calculate projected yields and selling prices. Knowing fertilizer prices plus soil test levels helps to plan accordingly, he adds.
Hergert says nitrogen prices have finally leveled off and declined to levels last seen back in 2006, adding that world demand for fertilizer decreased during the economic crisis, leading to an excess in fertilizer.
He says there is some indication that some major manufacturers in Russia are cutting production, which could increase prices later. Fertilizer prices f.o.b. the U.S. Gulf are under $280 per ton and ammonia f.o.b. for the Corn Belt is now near $320 per ton.
Hergert says soil testing is the best way to determine fertilizer requirements for wheat. Because soil nitrate is mobile, he says soil samples should be taken to at least a 3-foot depth before each wheat crop. (See the UNL NebGuide, Guidelines For Soil Sampling, for further information.)
"Soil samples for pH, phosphorus, potassium and micronutrients should be done every 3 to 5 years as these values do not change rapidly even with fertilization," Hergert says. "The topsoil sample should be taken from the 0 to 8-inch depth."
When calculating nitrogen and phosphorus recommendations for wheat, information from soil tests, plus fertilizer prices and the expected selling price should be included, Hergert says (Fertilizing Winter Wheat, EC143).
"Fertilizer prices should be lower than last year and wheat prices are ranging from $3.50 to $4 at local elevators and higher on the Kansas City and Chicago markets. Based on current prices for nitrogen and wheat, nitrogen application is still profitable," Hergert says.
Phosphorus prices for 18-46-0 (DAP) more than quadrupled before falling back to 2006 levels.
"Applying phosphate is also still profitable," Hergert says. "Nebraska data shows up to a 20 bushel-per-acre increase when applying phosphorus for low soil-test phosphorus and up to 10 bushel-per-acre increases when applying to medium phosphorus soils."
According to Hergert, the most profitable phosphorus rate depends on:
- The P source used
- Wheat and fertilizer prices
- Soil pH and
- The method of application.
Row or dual-applied phosphorus is more efficient than broadcast applications, Hergert says. Newer ammonia applicators with coulters allow narrower application (15 inches) and also operate at shallower depths (5 to 7 inches), greatly reducing power requirements. This has been a standard practice with older knife (dual) placement which has been around for 20 years.
Dual-applied phosphorus and seed-applied phosphorus perform equally well at optimum seeding dates.