Field experiment was carried out at the Experimental Station Farm in Giza, ARC, Egypt, during 2012 and 2013 seasons to study the effect of varying sources and rates of nitrogen fertilizers on fresh and dry forage yield of sudangrass, chemical constituents, nitrate and nitrite accumulation in plant. It can be recommended that mineral fertilizing sudangrass plants with 100 kg N/fed as ammonium sulphate in order to maximize its forage yields and reduce nitrate and nitrite accumulation in plant under the environmental conditions of Giza Governorate, Egypt. Biological experiment was carried out to...