How Biochar Contributes to Sustainable Agriculture: Impacts on Soil Health, Crop Productivity, Resource-Use Efficiency and Carbon Sequestration

Sustainable agriculture requires production systems that maintain crop productivity while conserving soil, water, nutrients, and other natural resources. Biochar has emerged as a promising carbon-rich soil amendment with potential applications in sustainable and climate-resilient agriculture. It is generally produced through the thermochemical conversion of biomass under oxygen-limited conditions and possesses distinctive physicochemical properties, including a porous structure, relatively stable carbon, variable surface functional groups, and, in many cases, considerable nutrient-retention capacity. The agricultural effects of biochar depend strongly on the type of feedstock, production conditions, application rate, soil properties, crop species, and environmental conditions. Evidence from scientific studies indicates that appropriately selected biochar can improve soil physical properties, increase nutrient retention, enhance water-holding capacity, influence soil microbial activity, and support crop growth, particularly in degraded, acidic, coarse-textured, or nutrient-poor soils. Biochar can also contribute to long-term carbon storage because a proportion of its carbon is relatively resistant to microbial decomposition. Furthermore, conversion of agricultural residues into biochar provides an opportunity for waste valorization and nutrient recycling within a circular bioeconomy. However, biochar is not universally beneficial, and inappropriate feedstocks, production conditions, or application rates may cause undesirable effects such as excessive alkalinity, salinity, nutrient imbalance, or contaminant introduction. Therefore, biochar should be regarded as a site-specific soil management tool rather than a universal substitute for fertilizers. This article discusses biochar production, properties, interactions with soil, effects on nutrient and water management, crop productivity, soil microorganisms, carbon sequestration, environmental sustainability, limitations, and future research priorities