The study looked at how different amounts of nitrogen affected the growth and yield of a type of tobacco called K326. By using different nitrogen levels (0, 27.0, 54.5, 81.8, 109.0 kg/ha) in the field, the researchers found that increasing nitrogen led to bigger leaves, taller plants, higher yield, and more chlorophyll. The best results were seen with 81.8 kg/ha of nitrogen, after which the yield started to decrease. So, for the best tobacco output in Yuxi district, it's recommended to use 81.8 kg/ha of pure nitrogen.