The study looked at how using crop residues and N-fertilizer affects the N recovery rate of summer maize. They found that using both straw and N-fertilizer helped improve the N recovery rate of summer maize. Specifically, optimized N-fertilizer application increased the N recovery rate by 3.12~7.39 kg/hm2. The best approach for maximizing crop yield, income, and reducing environmental impact was found to be incorporating crop residues into the soil along with optimized N-fertilization.