[en] The present work aimed at utilization of wastelands and improving their fertility status through the following topics:1- Isolation and identification of rhizobia from wastelands, then selecting the most resistant isolate to saline conditions.2- Studying the effect of radiation on the most salt tolerant rhizobia and marketing rhizobia using molecular and microbiological techniques.3- Identification and culturing of selected compatible rhizobia to be used in application experiments as a bio fertilizer to inoculate the leguminous crops in order to improve the efficiency of the Rhizobium-legume symbiosis and reclamation of wastelands.4- Application of molecular and nuclear techniques such 16S ribosomal RNA and studying the sequence for these strains for comparison between the most potent rhizobia.5- Determination of protein profile for the most potent rhizobia to throw light about similarities between these strains.6- Attempts to apply polymerase chain reaction (PCR) and use primers for differentiation between the most potent rhizobia.7- Experimental fields for growing some leguminous plants inoculated with irradiated and non-irradiated rhizobia and irrigated with different concentrations of sea water and their effects on growth and total N content of plants.