Wheat harvest is complete across Nebraska. Many of the wheat-fallow production areas have had good precipitation, setting the stage for good yield potential for next year's crop with sound fertilizer management. Wheat prices have rebounded in the last few weeks, but fertilizer prices have continued to climb since the beginning of the year.
Given these economic factors, producers should calculate projected yields, selling prices and fertilizer prices and plan accordingly, according to Gary Hergert, UNL Extension soils specialist in Scottsbluff
One of the first steps is soil testing, he says.
Soil sampling and testing are essential to determine fertilizer requirements for a profitable wheat crop. The most important nutrients for winter wheat production are phosphorus and nitrogen.
Soil samples for pH, phosphorus, potassium, and micronutrients should be done every three to four years since these values do not change rapidly even with fertilization. The topsoil sample should be from the 0- to 8-inch depth.
Soil samples for soil nitrate should be taken one to three months before planting each wheat crop. In most dryland wheat production areas, wheat will root to a 5-foot depth with a full profile of soil water. This should be the case for the 2012 crop in much of western Nebraska due to above normal rainfall this spring and early summer, Hergert says.
Soil samples should be taken from the surface depth and at every foot to at least a 3- or 4-foot depth and analyzed for nitrate-N. The results will help you fine-tune your N fertilizer recommendations.
Applying phosphate is also profitable. Nebraska data shows up to 20 bushels per acre increases to applied P at low soil test P and up to 10 bushels an acre increases for medium P soils. The P rate depends on P source used, wheat and fertilizer prices, soil pH and the method of application.
Row or dual-applied P is a more efficient method of P application than broadcast. 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 25 years. Dual-applied P and seed-applied P perform equally at optimum seeding dates.