A Comprehensive Review on Biostimulants for Sustainable Agriculture: Global Market Trends and Experimental Challenges

Biostimulants are substances, either natural or synthetic, that enhance plant growth without functioning as fertilizers or pesticides. According to the European Biostimulants Industry Council and EU regulations, biostimulants improve the efficiency of nutrient use, help plants withstand challenging conditions, and increase crop yields by activating specific plant functions. Unlike biofertilizers, which supply nutrients through living microbes, biostimulants influence plant development and interactions with beneficial microbes. The main types include enzyme formulations, beneficial microbes such as fungi and bacteria that promote growth, natural soil-derived acids, digested proteins, amino acids, and extracts from plants and seaweed. These products enhance root development, nutrient absorption, water regulation, and stress resistance. As climate change, soil degradation, and the demand for sustainable agriculture intensify, biostimulants present a promising alternative to chemical fertilizers by strengthening crop resilience and supporting environmental health. The global biostimulants market was approximately USD 3.0 billion in 2022 and is projected to reach USD 5.4–6.85 billion by 2027–2030, driven largely by microbial and liquid formulations. Europe leads in biostimulant adoption, but rapid growth is also occurring in Asia–Pacific, particularly in India, which represents a significant and expanding market. Despite ongoing challenges related to regulations, testing, and quality assurance, biostimulants are emerging as vital tools for sustainable farming and food security.