The aim of this research was to study the possibility of using bio- organic manures instead of mineral fertilizers for increasing potato growth production and soil fertility status as well as improving soil physical, chemical and biological properties.The present investigation was carried out at the Faculty of Agriculture Farm of the South Valley University,Egypt.Nitrogen fertilizer was used at three levels (One fourth of the recommended dose, half of the recommended dose and three fourth of the recommended dose) (R.D. was 150kg N/fed). Moreover, inoculation with biofertilizers i.e. Azotobacter spp, Azospirillum spp and Mixture of Azotobacter plus Azospirillum were used. Compost at three rates (10ton/fed, 15ton/fed and 20ton/fed), were applied also.the objective of the present study was to investigate the effect of three different fertilizers (Nitrogen fertilizer, bio-fertilizers and organic fertilizers) on the yield and quality of potato. Moreover, the influence of different types of fertilizers on nitrate and nitrite contents in tuber potato was studied. Skryť popis