Excellence in Research: Innovative Engineered Biochar Applications for Brackish Water Irrigation

About This Grant

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. It is a great challenge for coastal regions to efficiently use brackish water for irrigation owing to the accumulation of salinity in the soil. Ca2+-enriched biochar has the potential to be used for brackish water irrigation by removing Na+ from brackish water and releasing Ca2+ to improve the soil sodicity. The objectives of this project include 1) foundational understanding of Na+ adsorption and Na+ and Ca2+ exchange in Ca2+-enriched biochar and 2) implementation of innovative engineered biochar applications for brackish water irrigation. In this project, innovative Ca2+-enriched biochar will be produced using various feedstocks at different pyrolysis temperatures, which will then be used in batch adsorption and column experiments to investigate Na+ adsorption, Ca2+ displacement, and Na+ and Ca2+ distribution in the soil profile. Quantitative Structure–Activity Relationships (QSAR) analysis and PHREEQC modeling will be conducted to help with the theoretical understanding of the above processes. Implementation of engineered biochar for brackish water irrigation will be evaluated in terms of irrigation water salinity reduction and soil sodicity abatement in greenhouse crop growth experiments. The findings of this project will advance theoretical understanding of Na+ adsorption and Ca2+ displacement in sodic soils. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.