Microalgae as a multifunctional solution for sustainable agriculture: Starting with soil improvement

• Microalgae perform excellent in improving soil fertility, structure, and safety. • Microalgae provide reliable solution to alleviate and repair soil degradation. • Practical application require technological, commercial, and policy support. Global population growth and increased food demand present challenges to enhancing the productivity and quality of agriculture systems in a sustainable manner. As the material foundation of agriculture, soil plays a decisive role in its capacity and sustainability. Centering on soil quality improvement, this review systematically summarizes the advanced strategies for sustainable agriculture driven by microalgae—an emerging bioresource—with an emphasis on mechanistic insights and feasibility analysis. In pervious researches, microalgae have demonstrated reliability in maintaining soil fertility, improving soil structure and ecological stability, and addressing soil-borne diseases and contamination; their strong adaptability was also proved favorable for restoring degraded soils and expanding arable land. However, the commercialization of microalgae-based soil improvement strategies still faces challenges in terms of high-quality germplasm, advanced technology, and guaranteed economic returns. Through an in-depth discussion of current obstacles and future breakthroughs, this article aims to provide informative insights for researchers and investors dedicated to the pursuit of agricultural sustainability.