Biochar, a carbon-rich material derived from the pyrolysis of biomass under limited oxygen, has emerged as a powerful tool in addressing the twin challenges of declining soil health and stagnating crop productivity. This paper explores biochar?s multifaceted role in improving soil physical, chemical, and biological properties, its capacity to enhance nutrient retention and water use efficiency, and its potential to sequester carbon while promoting agricultural sustainability. Drawing on data from over 30 peer-reviewed journals and global reports, the paper highlights key mechanisms through which biochar acts as a soil amendment, from altering pH and reducing bulk density to stimulating microbial activity and suppressing plant pathogens. Case studies from India, Brazil, China, and Sub-Saharan Africa show that biochar application can lead to yield increases ranging from 10% to 45% depending on soil type, crop, and climate conditions. However, the article also discusses risks and limitations such as feedstock selection, application rates, and socio-economic constraints. By integrating biochar into climate-smart agricultural frameworks, this study calls for a policy shift toward sustainable biochar production, localized application strategies, and more participatory research with farmers. The conclusion underscores the urgent need to scale biochar use responsibly as a nature-based solution for soil regeneration and food security. This work contributes to the growing evidence base that biochar is not just a byproduct, but a strategic input for resilient and productive agroecosystems.