Spirulina-Based Biostimulants for Sustainable Agriculture: Yield Improvement and Market Trends

The tension between a growing food global demand, rising environmental impacts of agricultural intensification, and the uncertainty of future climate changes highlight a crucial need for sustainable agricultural practices to improve crop productivity. One promising way is the use of plant biostimulants that act at several levels of the agricultural ecosystem to improve crop yield. Spirulina spp., the most produced microalgae, is characterized by a rapid growth and an interesting composition which make it the first choice for different applications mainly nutritional ones. Recently, Spirulina attracted the attention of researchers and agroindustries as a renewable resource for agricultural inputs. Indeed, besides its naturally fertilizing potential, Spirulina is able to release various biologically active molecules (polysaccharides, amino acids, phytohormones, etc.) that promote plant growth and increase tolerance to biotic and abiotic stresses. Spirulina-based biostimulants are applied by several methods depending on the objective and crop needs. Nevertheless, their application at large scale is still limited by various factors including cost. In this way, the current review summarizes previous utilizations of Spirulina-based products. It highlights their efficiency for various purposes, determines the factors limiting their use, as well as future development priorities and perspectives.