The study looked at how different amounts of nitrogen fertilizer affect the nitrogen and chlorophyll levels in cotton leaves. They found that as more nitrogen was added, the nitrogen content in the leaves increased. The type of soil also affected the nitrogen levels in the leaves. The researchers discovered that the color of the leaves changed depending on the nitrogen levels, and this color difference could be used to determine the plant's nutrition status. Overall, the study showed that nitrogen fertilizer can impact the health and nutrient levels of cotton plants, which can be seen through changes in leaf color and nitrogen content.