The researchers studied how adding urea and different substances to wheat straw affects its nitrogen content and composition. They found that increasing urea levels raised the nitrogen content, especially when combined with acetic or formic acid. Adding corn steep liquor or acidified molasses further increased nitrogen content. However, nitrogen retention decreased as urea levels rose. Most nitrogen was in a form called neutral detergent insoluble N. Fiber content increased with additives, particularly hemicellulose. Cellulose decreased with higher urea levels. Overall, the study shows how different treatments can alter the nitrogen and fiber composition of wheat straw.