The study looked at how different amounts of phosphorus fertilizer affected the levels of nitrogen, phosphorus, and potassium in tobacco plants. They found that as more phosphorus was added, the levels of phosphorus and potassium increased in the roots, stems, and leaves, while nitrogen levels decreased in the roots and leaves. The total amounts of nitrogen, phosphorus, and potassium in the plants also increased with higher phosphorus levels. The distribution of phosphorus in the roots increased with more fertilizer, but the overall distribution of nitrogen, phosphorus, and potassium in the plants stayed the same.