A System for Fertigation Management in Closed-Loop Soilless Culture of Tomato

Protected cultivation of tomato is specific to the production for fresh market. In Italy, most greenhouse growers apply fertigation with free drainage (open-loop system) but recent legislation concerning environmental pollution from point source is forcing them to introduce new management approaches, namely the recirculation of drain water (closed-loop system). To support the growers in selecting low impact growing systems and in reducing water use a specific support system (SGx) is under construction. SGx integrates three main simulation models of plant growth and transpiration as well as the nutrient concentration in fertigation water. The system can run both in real time, using meteorological and water consumption data automatically collected by in situ sensors, and off-line using data sets archived in the database. In real time modality, the system follows plant growth and the modification of recycling nutrient solution and advices growers about to the most effective practices in term of crop growth and water and nutrient use. The off-line modality allows different fertigation strategies to be evaluated from the viewpoints of economics and environmental impact.