Spatially distributed greenhouse climate control based on wireless sensor network measurements

In modern greenhouses, several measurement points at plant level are required to create an objective and detailed view of the climate at various regions around the covered space. Specific climatic gradients can cause significant differences in terms of yield, productivity, quantitative and qualitative characteristics of the plants, as well as the development of various diseases. This work presents the development of a distributed monitoring system using a wireless sensor network (WSN) in a commercial greenhouse, towards the realization of a spatially distributed control methodology, based on specific spatial variations of the measured environmental variables. The distributed measurements acquired by the wireless nodes are analysed to represent the spatial variation of the environmental conditions inside the greenhouse, which can subsequently be used to develop precise control strategies that could lead to more uniform conditions throughout the entire cultivation area and better control of crop needs. In this way, uniform quantity and quality of produce can be achieved, while the risk of diseases at specific problematic regions of the greenhouse could be minimized. Analysis based on WSN measurements during summer and winter periods showed significant spatial variability in temperature and humidity, but also in transpiration and conditions that favour condensation on leaves surface.