Today, algae and their biological capabilities have been considered as subject of many studies. Algae have many usages in agricultural biotechnology food and medical. The diversity of end products of different algae and their cultivation which are used in agriculture, makes algae as a unique biological resource.
Over use of chemical fertilizers, pesticides and herbicides in agricultural lands causes environmental crises such as micro flora imbalance, loss of stability and balance the tensions. The application of bio-fertilizers has an important role in the management of the food supply. Cyanobacteria uses the nitrogenase enzyme and absorbed nitrogen of air to convert into nitrogen compounds. Regarding to algae ability to be toletent in different environmental conditions such as high temperatures, drought, pH, salinity and light intensity. Therefore they are suitable choice for agricutural usage in different situations.
Due to the string and sticky materials and gel structure, algae can increase soil pores and soil water holding capacity, respectively. Also, they reduce soil salinity, prevent soil erosion and improve their structure. The algae extract that contains a variety of biologically active substrates, such as gibberellin, auxin, cytokinin, vitamins, amino acids, polypeptides, antibacterial and antifungal substrates have a significant impact on yields and agricultural production. In this study, algae identified in the southern coast of Caspian Sea for employment in agriculture (biofertilizers, growth regulators, pesticides and improved soil structure) has been surveyed.