A review of biochar-based fertilizers and their applications in sustainable agriculture



Abstract

Biochar-based fertilizers have emerged as an innovative approach for sustainable soil management and optimized plant nutrition in response to resource limitations and increasing food demand. Owing to their high specific surface area, suitable porosity, and presence of active functional groups, these fertilizers improve the physical, chemical, and biological properties of soils while enhancing cation exchange capacity and aggregate stability. They also regulate nutrient release kinetics, thereby reducing nutrient losses caused by leaching and volatilization. This review examines recent advances in biochar production technologies, activation methods, and enrichment strategies, along with their applications in soil–plant systems. Evidence indicates that the use of biochar-based fertilizers increases stable soil organic carbon, enhances microbial activity, and improves the efficiency of both macro- and micronutrient use, ultimately leading to higher crop yields and improved product quality. In addition, these fertilizers contribute to mitigating the environmental impacts of agriculture by regulating redox conditions, increasing nitrogen and phosphorus retention, and reducing greenhouse gas emissions. However, challenges such as variability in biochar properties and inconsistent soil and plant responses still remain. Therefore, the development of optimized formulations and long-term field studies is essential.