A study in North Henan looked at how combining straw with nitrogen fertilizer can improve nitrogen use in winter wheat. They tested different amounts of nitrogen and straw in the soil. Results showed that using both straw and nitrogen together increased nitrogen harvest index, protein content in grains, and grain yield. At the same time, soil nitrate content decreased after the winter wheat harvest. This means that using straw along with nitrogen can help crops grow better and use nitrogen more efficiently.