A study looked at how adding nitrogen fertilizer and rhizobium bacteria to soybean plants affected their growth and yield. They found that plants with rhizobium bacteria had more nodules, which help with nutrient uptake. However, too much nitrogen fertilizer reduced the number of nodules. Plants with both rhizobium bacteria and a small amount of nitrogen fertilizer had the highest seed yield. These plants also had more pods and seeds per pod. The seeds from plants with rhizobium bacteria had higher protein content compared to those without, but there was no difference in oil content. Overall, using a small amount of nitrogen fertilizer along with rhizobium bacteria is a good practice for growing soybeans in Sudan.