A Standalone FLC Framework for Controlled Fertigation in Protected Horticulture

Protected horticulture fertigation (fertilizers + water) is prone to water shortages, fertilizer wasting and the chances of domestic water contamination, with the corresponding associated costs. Here, a standalone framework with IoT capabilities and cloud management amenable for low budget production facilities is proposed. The system provides with substrate temperature, ambient temperature and automatic fertigation drainage measuring using off-the-shelf sensors and components, and integrating information from electrical conductivity (EC) and pH variables. Data driven decisions are determined via a Fuzzy Logic Controller (FLC) run either online or from a IoT platform. The FLC evaluates automatic drainage measuring, EC and pH values to determine if water content is easily available to crops, with lexical uncertainty quantified into a numerical value, giving an output scalar value associated for fertigation decisions. Ambient and substrate temperature, along with humidity are also synchronized with the controller, providing a data analysis framework giving insights on long term production performance vis à vis weather conditions and seasonal conditions. Practical knowledge about fertigation is integrated into an analytic framework, providing ready access to a particular crop's main production and growth related variables, and allowing for future data driven decisions. The system has been repeatedly validated with real data collected from tropical crops.