Wireless Sensor Networks for Automated Irrigation Control in Container Nurseries: Implementation and Economic Impact

The SCRI–MINDS project has developed hardware and software to efficiently irrigate ornamental crops.  Two large demonstration projects were implemented in 2011 in commercial nurseries in the state of Georgia to assess the use of wireless sensor networks and associated software as a management tool for nursery irrigation systems.  Two years into this cooperative project, we have been able to assess that growers: 1) can successfully adapt their management strategies using this technology and learn the system within a few months of use; 2) see documentable economic benefits; and 3) implement additional management changes that improve production as a result of using the network.  Both growers found that using the system was beneficial to crop health, improved time management, and shortened production cycles. Irrigation water use was significantly reduced in both operations.  The most dramatic results so far have been observed in Gardenia jasminoides, a crop that can be difficult to grow and suffers from serious disease losses (often causing shrinkage between 30% to 70%). Irrigation control using the wireless sensor network resulted in significant economic benefits.  The economic analysis showed a 148% increase in annualized profits. This largely resulted from a shorter production cycle (decreasing production costs) and, to a lesser extent, from eliminating plant losses due to root pathogens. Based on these increased profits, the payback period for the sensor network was less than one month. Although the economic benefits will not be this high in all crops, this clearly shows the potential for wireless sensor networks to improve production efficiency of difficult crops. In addition to the benefits of automated irrigation control, one grower specifically reported on the importance of the weather station that is part of the system, for management decisions such as when to pull frost cloth, to relocate plants to a different production area, and for tracking heat-load in the production areas as a result of installing the systyem.  Both growers have been increasing the production areas where irrigation is controlled by the sensor network, indicating that they trust the system to provide good irrigation control.