Two field experiments were conducted in summer seasons of 2010 and 2011 at Agricultural Research
Station, Faculty of Agriculture; Suez Canal University at Ismailia governorate; Egypt. The soil textures of experiments
were sandy. The experiments are aimed to study the response of Sudangrass cv. Giza "2" to three phosphorus fertilizer
rates (0, 37 and 74 kg P2O5/ha), three rates of nitrogen (74, 121 and 171 kg N/ha), and two seeding rates (24 and 36 kg
seed/ha). The design of each experiment was split-split plots design. Sowing date was 9th of May in two growing
seasons. Plant height, leaves and stem fresh weight/plant, total plant fresh weight, leaf-stem ratio, green forage
yield/cut, total green forage yield/season, CP %, and CP yield/cut were increased by increasing phosphorus fertilizer
rates up to 74 kgP2O5/ha, and also, it were increased by increasing nitrogen fertilizer rates up to 171 kg N/ha, while
crude fiber % was increased by increasing phosphorus levels and decreased by increasing nitrogen levels. At all cuts,
increase seeding rates up to 36 kg/ha significantly increased plant height, green forage yield/cut and total green forage
yield/season, but decreased significantly leaves and stem fresh weight/plant, total plant fresh weight, but didn't affect
significantly leaf-stem ratio, CP yield/cut, and CF %..