The study looked at how different ways of managing crop residues affect crop yields and nitrogen use efficiency. They found that incorporating crop residues into the soil, especially when combined with poultry manure, increased yields for maize, sugar beet, and winter wheat. Using residues reduced the need for fertilizers, but didn't improve soil quality much. The effects of residue management varied depending on the type of crop and when it was planted. Overall, incorporating crop residues can boost crop yields and reduce the need for chemical fertilizers.