Azospirillum, a Free-Living Nitrogen-Fixing Bacterium: Smart Agriculture and Sustainable Exploitation

More than a century has passed since the worldwide emergence of biofertilizers in the field of industry and agriculture, and more than a decade has passed since their production in Iran. Biofertilizers have a vital place in sustainable and organic agriculture. Despite understanding the functional mechanism of bacteria and their role in developing a more efficient environment in agriculture, the use of these bacteria in plant products, which is not so novel and emerging in the eyes of the scientific community, needs more correct and valid information. This is related to the complexity caused by the variety of cultivated species. The interaction between the plant and microorganisms is not only associated with plant adaptation but also deals with various factors, including the characteristics of the culture environment. In this article, we have tried to have an overview of their mechanism of action by looking at the history of biofertilizers and introducing their various examples. We have also attempted to evaluate their position and status in our country. We will mention some nitrogenous biofertilizers, including rhizobium bacteria, azotobacter, and Azospirillum. At the end of each article section, there is a brief mention of the isolation method of important microbial species as potent biofertilizers. Finally, we have pointed out the research and use of these fertilizers in various experiments and their consequences on plant growth and quantitative and qualitative characteristics.