Lignin valorization toward eco-friendly agricultural inputs

The sustainable transformation of modern agriculture requires environmentally friendly materials that can reduce chemical dependence and environmental impacts. As the most abundant natural aromatic polymer, lignin offers unique structural and functional versatility for developing next-generation agricultural inputs. This review summarizes recent advances in the preparation, structural design, and application of lignin-derived materials for green agricultural inputs, including controlled-release fertilizers, pesticides, soil amendments, mulch films, and seed coating agents. The intrinsic properties of lignin, such as antioxidant activity, ultraviolet (UV) shielding, antimicrobial functionality, and tunable degradability, enable the design of multifunctional systems that improve nutrient use efficiency, crop productivity, and soil health while reducing pollution. Progress in chemical modification, polymer blending, and bio-based formulation strategies is discussed in relation to structure–property-performance relationships. Finally, key challenges, including lignin heterogeneity, environmental safety, material cost, and compatibility with agricultural practices, are critically analyzed, and future directions integrating lignin valorization with circular bioeconomy and sustainable agriculture are proposed. This review aims to provide comprehensive insights into lignin’s potential as a versatile platform for agricultural innovation and environmental protection.