Water Management Sensing and Technology in Citrus Orchards

The reduction of water availability encourages the adoption of effective saving strategies supported by current technologies as a key tool for a sustainable citrus industry. Monitoring of soil moisture and plant status is necessary during the crop cycle. The trial was carried out during the irrigation season (June-October 2022) in an orange grove cv ‘Tarocco Rosso VCR’ [Citrus sinensis (L.) Osbeck] grafted on Carrizo citrange rootstock [Poncirus trifoliata (L.) Raf. × C. sinensis (L.) Osbeck]. The monitoring was carried out both in field and remotely. Two treatments were compared: dual drip line irrigation to replace 100% of ETc (SDI) and sub-surface drip irrigation system to replace 80% of crop evapotranspiration (ETc) (SSDI). The daily mean soil water content (SWC, θv) was monitored with a probe above (15 cm) and below the subsurface drip line (40 cm). Satellite information was derived from available Sentinel-2 satellite products and the distribution map files of the reflectance values of the selected bands were processed by R software. The NDVI spectral index showed a similar trend between the two treatments. The SWC fluctuations observed in the subsurface irrigation treatment at both depths were influenced by irrigation timing and volumes. A moderate water stress is a sustainable strategy to save water, increase irrigation efficiency without altering yield and fruit properties. The combined use of proximal and remote monitoring of citrus groves seems to be the frontier of irrigation management.