In Egypt , salt-affected soils could be more potentially ptoductive by applying new techniques of soil fertility management practices . The lower productivity of salt affected soils could be ascribed to salinnity influence on germination, growth and yield of most crops . The disturbances in mineral nutrition and deficiency in some of the important elements obiviously upset the development cycle of the plant grown on saline soils . Reviewing the literature indicates that increasing salinity levels reduced the yield of many field crops as sorghum, cotton,corn, a d wheat . The purpose of this works is to study the combined effects of soil salinity , soil conditioner , nitrification inhibitor, and N - fertilizers source on the release and efficiency of nitrogen fertilizers applied to alluvial clayey soil growen with sorghum and cotton.