Online professional irrigation scheduling system for greenhouse crops

A knowledge-based system was built for online precise irrigation scheduling (OpIRIS) using advanced results from research projects on water and fertilizer productivity of hydroponic greenhouse crops. Thus, an irrigation scheduling algorithm was built in a web-based application. Microclimate sensors installed in the greenhouse are connected to device-to-web data loggers that feed a sensor data database. The algorithm module calculates the crop transpiration rate based on solar radiation, air temperature and relative humidity measurements and, taking into account measurements of substrate water content, nutrient solution supplied and drained, estimations of crop leaf area index and the weather forecast, indicates when to irrigate and how much nutrient solution to apply. The system was tested and evaluated in two commercial farms in Greece, and the results indicated that the system can accurately predict crop water needs in advance. Application of the system resulted in 100% increases of water- and fertilizer-use efficiency.