49th TWC, Tob. Work. Conf., 2020, abstr. 18

Comparisons of nitrogen based fertilizer programs in tobacco

North Carolina State University, Raleigh, NC USA

Previous fertilizer research in flue-cured tobacco has compared a wide range of nitrogen (N) based programs, ultimately demonstrating the usability and function of numerous sources. However, those research efforts have not fully investigated the influence of N based sources to the assimilation of other nutrients.  Preliminary research was conducted in 2019 to evaluate various combinations of basal and sidedress N sources. Basal treatments consisted of granular 6-6-18 or liquid urea-ammonium nitrate (UAN) and potassium sulfate. Sidedress N sources were ammonium nitrate potassium, ammonium nitrate sulfate, or UAN. Each basal and sidedress source was paired to create a 2 x 3 factorial treatment arrangement.  Four weeks after transplanting, the analysis of foliar tissue samples revealed higher concentrations of phosphorus and potassium in treatments containing 6-6-18 relative to UAN and potassium sulfate. These trends were not observed at flowering, indicating that over a longer period of growth nutrient assimilation is normalized in well-fertilized and maintained fields.  After curing, leaf potassium was greatest in treatments containing 6-6-18 + ammonium nitrate potassium relative to 6-6-18 + UAN, UAN + UAN, and UAN + ammonium nitrate potassium. Despite these differences, cured leaf yield, quality, price/kg, and value/ha were similar, meaning that these nutrient sources may not prove deleterious to tobacco growth. This point is further reinforced by the fact that nutrient concentration was deemed sufficient within each sampling interval, regardless of treatment. This research will continue in 2020. (Reprinted with permission)