This review aims to provide a comprehensive overview of the current state of knowledge on the effect of drought stress on the productivity of vegetable crops as well as the impact of applying melatonin to plants exposed to drought stress. Additionally, the study aims to investigate the beneficial role of rhizobium inoculant in nitrogen fixation using different solutions containing molybdenum, cobalt, and copper. By examining the existing literature, this review seeks to synthesize and analyze the key findings, trends, and gaps in research to date. The water scarcity crisis in Egypt (present status and future projections) will be highlighted as well as the effect of water deficit and plant performance, the role of melatonin as a hormone that suppresses the effects of water deficit on plants, biological N-fixation and stimulants of biological N-fixation. Additionally, this review will identify the significant challenges and opportunities in the field, with the ultimate goal of informing future research directions and practical applications.