Saltwater intrusion into coastal aquifers increases freshwater salinity, posing a growing threat to agriculture. As brackish water used for irrigation becomes saltier, crop yields decline, soil quality deteriorates, and food security is put at risk. A valuable tool for mitigating saltwater intrusion impacts is engineered biochar, which is a carbon-rich material produced through thermal decomposition of organic materials in a low-oxygen environment at varying temperatures. Biochar not only removes excess sodium from the soil but also adds calcium, improving soil structure, drainage, and plant growth. This project will explore how biochar enriched with calcium can help remove excess sodium from soil and create a model to describe the fate and transport of sodium and calcium in the soil profile, helping to improve water and soil quality for farming. The modeling framework will guide the effective use of engineered biochar for brackish water irrigation, advancing this innovative approach toward more sustainable and resilient agricultural practices. Additionally, this project will offer STEM students hands-on experience in tackling real-world environmental challenges, preparing them for future problem-solving in water and soil management. This project will advance the use of calcium-enriched biochar for brackish water irrigation and provide essential guidelines to support policymakers and decision-makers in developing sustainable and resilient irrigation management strategies.