The study looked at how different levels of nitrogen fertilizer and plant density affect the yield of grain sorghum in Iran. They found that using 150 kg of nitrogen per hectare increased grain yield significantly. Increasing plant density up to 50 plants per square meter also improved yield, despite reducing grain weight. The best results were seen with 225 kg of nitrogen per hectare and a plant density of 50 plants per square meter, resulting in the highest grain yield of 2388.33 kg per hectare.