Ascophyllum nodosum (L.) Le Jolis, a Pivotal Biostimulant toward Sustainable Agriculture: A Comprehensive Review

Algae are existing macroscopic materials with substantial benefits, including as important growth regulators and macronutrients and micronutrients for the growth of healthy crop plants. Biofertilizers obtained from algae are identified as novel production fertilizers or innovative biofertilizers without the detrimental impacts of chemicals. Seaweeds contain many water-soluble minerals and nutrients that plants can easily absorb and that are valuable for crop plants’ growth. At present, Ascophyllum nodosum (L.) Le Jolis extract outperforms chemical fertilizers in terms of increasing seed germination, plant development, and yield, as well as protecting plants from severe biotic and abiotic stresses. A. nodosum contains bioactive compounds that exhibit an array of biological activities such as antibiotic, anti-microbial, antioxidant, anti-cancer, anti-obesity, and anti-diabetic activities. A. nodosum extract (AnE) contains alginic acid and poly-uronides that improve soil’s water-carrying ability, morsel structure, aeration, and capillary action, stimulating root systems in plants, increasing microbial activity in soil, and improving mineral absorption and availability. The scientific literature has comprehensively reviewed these factors, providing information about the different functions of A. nodosum in plant growth, yield, and quality, the alleviation of biotic and abiotic stresses in plants, and their effects on the interactions of plant root systems and microbes. The application of AnE significantly improved the germination rate, increased the growth of lateral roots, enhanced water and nutrient use efficiencies, increased antioxidant activity, increased phenolic and flavonoid contents, increased chlorophyll and nutrient contents, alleviated the effects of abiotic and biotic stresses in different crop plants, and even improved the postharvest quality of different fruits.