A study looked at how different amounts of nitrogen fertilizer affected the growth and quality of a type of tobacco called Yunyan-87. They used two levels of nitrogen and found that the higher level led to more chlorophyll in the leaves, better photosynthesis, and higher levels of certain enzymes. The tobacco plants also had higher nicotine and potassium content, but lower sugar content in their leaves. Overall, the tobacco plants given more nitrogen had better quality and higher prices for their leaves compared to those with less nitrogen.