The study looked at how different levels of nitrogen fertilizer affect maize growth in a dry area of China. They found that using higher amounts of nitrogen fertilizer (200-300 kg/ha) led to better water use efficiency, increased crop biomass, and higher grain yield compared to lower amounts. This means that applying the right amount of nitrogen fertilizer can help maize plants grow better and produce more grain, especially in dry areas. The study suggests that using 200-300 kg/ha of nitrogen fertilizer could improve maize production while minimizing environmental impact.