From Mechanisms to Application: A Case-Based Review of Paulownia-Derived Biochar in Turfgrass Systems

Biochar has emerged as a multifunctional soil amendment with the potential to mitigate soil degradation, nutrient loss, and water scarcity. However, its effectiveness depends strongly on feedstock type and production conditions, limiting consistent application across agroecosystems. This review focuses on Paulownia leaf-derived biochar (PLB) as a promising feedstock for sustainable soil management. Current knowledge on its production, physicochemical properties, and mechanisms of interaction with the soil environment is synthesized, with emphasis on nutrient storage, water dynamics, and plant responses. To link process-based understanding with practical application, a case-based approach integrates literature evidence with a previously published experimental study evaluating PLB in turfgrass systems under different fertilization and irrigation regimes. The case study illustrates how feedstock-specific properties, including alkaline pH, high cation exchange capacity, mineral enrichment, and a developed pore structure, contribute to enhanced soil functions and turfgrass performance. The combined evidence indicates that PLB may enhance nutrient storage, water availability, and fertilizer-use efficiency, particularly in intensively managed systems. Overall, this review provides an integrated framework for understanding how the physicochemical properties of Paulownia leaf-derived biochar are translated into soil functions and agronomic responses, supporting the targeted selection and application of biochar for sustainable soil management.