THE IMPACT OF CONTROLLED UPTAKE LONG TERM AMMONIUM NUTRITION ON WINTER WHEAT YIELD AND QUALITY OF GRAIN

The effect of controlled uptake long term ammonium nutrition (CULTAN) on yield and grain quality of winter wheat was examined at three sites in a two-year small-plot field experiment. Two treatments using injection fertilization of all nitrogen in one dose (CULTAN system) were compared with two treatments using nitrogen surface broadcast fertilization in three doses. The effect of N-fertilizer containing sulphur was further examined in each fertilization system. The injection fertilization was applied at the end of winter wheat tillering in 2008 and at the beginning of spring vegetation in 2009. The grain yields of CULTAN treatments were lower in 2008; in the following year the grain yields of both fertilization systems were comparable. The differences were not generally statistically significant. Protein content, gluten content and sedimentation index were lower in CULTAN treatments in both years. Using the urea ammonium sulphate in CULTAN system instead of urea ammonium nitrate increased all measured characteristics in both years