Project Grant 20267000146132

Tennessee Technological University received a $150,000 Project Grant from the National Institute of Food and Agriculture (NIFA) under the Capacity Building Grants for Non-Land Grant Colleges of Agriculture (NLGCA) program (CFDA 10.326), awarded June 1, 2026, with performance through May 31, 2029. The project will develop a practical, data-driven decision-support model to optimize nutrient replenishment and discharge management in hydroponic tomato production systems. This research addresses the critical need to improve nutrient use efficiency in hydroponic systems, which now account for more than half of U.S. tomato production valued at approximately $2 billion annually. By integrating measurable production variables such as light intensity, vapor pressure deficit, and plant water use, the project will quantify how these factors influence nutrient fate and distribution within hydroponic fertigation systems.

The specific deliverables include a predictive model of plant transpiration based on vapor pressure deficit and solar radiation, and a production-scale model capable of estimating nutrient concentrations in discharge solutions to guide replenishment decisions. These tools will provide growers with actionable recommendations to reduce fertilizer costs and environmental impacts while improving overall nutrient management efficiency. The research directly supports long-term viability of hydroponic agriculture by addressing fertilizer input costs, which represent among the highest recurring expenses in hydroponic vegetable production, while simultaneously enhancing resource stewardship through improved water and nutrient management practices.