ABSTRACT
Due to the increase in the worldwide population, the demand for freshly produced vegetables has increased significantly. In order to meet this additional food demand, chemical fertilizers are added to the soil to enhance soil fertility and plant yield, which has several adverse effects in the long run. Moreover, an uncontrolled application of such synthetic fertilizers can lead to the scarcity of limited nutrient resources like phosphorus. Microalgae can be used as a potential alternative for the commercially available synthetic fertilizer, as they can enhance the soil fertility by fixing the nitrogen biologically and thus increase the nutrient availability for the plant through enhanced mobility and solubilization capacity. Furthermore, several bioactive compounds (such as phytohormones or extracellular polysaccharides) produced by microalgal strains have shown the potential to induce plant growth along with protecting them against different biotic and abiotic stresses. This chapter highlights the potential of microalgae as biofertilizers, biostimulants, and biopesticides, in sustainable agricultural practice to increase the overall yield.
