The study looked at how different amounts of nitrogen fertilizer affect the growth and efficiency of maize plants. In fields with high yields, too much nitrogen didn't help much and made the plants less efficient at using nitrogen. In fields with medium yields, more nitrogen increased the amount of maize produced but made the plants less efficient at using nitrogen. The researchers found that the order of nitrogen accumulation in different parts of the plant was grain, leaf, stem, root, and leaf sheath. They also discovered that certain enzymes in the plants were most active at a specific level of nitrogen fertilizer, and adding more didn't make them work better.