Development of an Advanced Sensor Network Node for Automated Monitoring and Control of Irrigation in Nursery and Greenhouse Production

Abstract

We have developed a smart wireless sensor (nR5) node that is capable of integrating outputs from a range of soil moisture and environmental sensors, and uses that information to determine when irrigations should be applied. This enables growers to implement irrigation set-point or model-based protocols, which are then executed by the sensor nodes, enhancing human decision-making. The nR5-DC version of the node can independently power a latching solenoid, allowing irrigation control in remote field situations. These nodes are low maintenance, have a reliable communications protocol, and a long battery life—greater than 6-months with five AA batteries during testing in 2012. To support node functioning and to allow growers to program the node, a web-based software program (Sensorweb) was also developed. Sensorweb has a sophisticated set of monitoring and control functions, enabling two-way communication and control of these wireless sensor networks in the field. The software fulfills three primary functions: 1) efficient management of nodes (configuration of sensors, set-points etc.); 2) organization of data transmitted from the sensor nodes in the field; and 3) display of that data in graphical form for quick decision-making by the grower. Each sensor network has a customized homepage in Sensorweb, which shows the unique farm layout and locations of the nodes in the network, allowing users to quickly view data "at a glance," while also giving the ability to further analyze sensor data using easy-to-use charting functions. The software also has a wide variety of irrigation control functions based either on sensor "set-points" or more advanced model-based tools based on environmental sensors. This new wireless sensor hardware and software has allowed for the automated control of irrigation applications and a reduction in total water use of up to 75%, in a number of commercial nursery and greenhouse environments during 2012.