Design and validation of a soil moisture-based wireless sensors network for the smart irrigation of a pear orchard

Abstract

In this study, a soil moisture-based wireless sensor network (SM-WSN) was transferred to support irrigation management at field scale. This smart irrigation service comes from a necessity and willingness to upgrade the regional weather-based decision support system of the Tuscany region (Italy). The sensor network was designed, hydrologically, and agronomically validated in a commercial pear orchard during four growing seasons (2019–2022). Initially, the micro irrigation system was assessed based on its water distribution uniformity (DU) performance. Then, a zoning analysis was carried out to delineate homogeneous areas according to the normalized difference vegetation index (NDVI) and soil bulk electrical conductivity (ECb). Unlike the ordinary irrigation scheduling applied in the farm, the smart system allowed maintaining the soil water content within a pre-defined optimal range, in which the upper and lower limits corresponded respectively to the soil field capacity and the threshold below which water stress occurs. Based on the smart irrigation management, a water-saving up to 50 % of the total water supplied with the ordinary scheduling was achieved during the investigated growing seasons. Moreover, the quality of the productions (i.e., °Brix, fruit size and flesh firmness) was in line with the standard market reference values. Consequently, the adoption of the new technology, which aims to identify the most appropriate irrigation management, has the potential to generate positive economic returns and reduce environmental impacts.