Wireless Sensor Networks for precision horticulture in Southern Spain

In recent years many applications have been proposed for Wireless Sensor Networks (WSN). One of these is precision agriculture, where WSN can play an important part in the handling and management of water resources for irrigation, in understanding the changes in the crops to assess the optimum point for harvesting, in estimating fertilizer requirements and to predict crop performance more accurately. This paper describes our experience during the introduction and deployment of an experimental sensor network at an ecological horticultural enterprise in the semiarid region of Murcia. It presents the topology of the deployed network using four types of nodes (Soil Mote, Environmental Mote, Water Mote and Gateway Mote), some of them connected to different sensors distributed in the field. These sensors can measure various soil characteristics such us temperature, volumetric moisture content and salinity. For each node, the overall architecture, hardware and software components are described. The system also includes a real-time monitoring application operating from a computer placed in the central offices of the farm. The testing of the system was done in two phases: the first in the laboratory, to validate the functional requirements of the developed devices, the networking solution and the mote's power management; the second on the farm, to asses the functional performance of the devices, such as range, robustness and flexibility. The system was successfully implemented on a crop of ecological cabbage (Brassica oleracea). The result was a low cost, highly reliable and simple infrastructure for the collection of agronomical data over a distributed area in horticultural environments.