Integrating Sentinel-2 Imagery with AquaCrop for Dynamic Assessment of Tomato Water Requirements in Southern Italy

Significant reductions in irrigation volumes at farm level can be achieved by assessing crop water requirements through the combination of crop satellite images and a crop growth model. Based on this hypothesis, a research study was conducted with open field tomato (Solanum lycopersicum L.) in order to: (i) Evaluate the capability of Sentinel-2 imagery to assess tomato canopy growth and its crop water requirements; and (ii) explore the possibility to predict crop water requirements by assimilating the canopy cover estimated by Sentinel-2 imagery into the AquaCrop model. Crop water use and irrigation requirements were estimated by means of three different methods: (i) the AquaCrop model; (ii) an irrigation advisory service based on Sentinel-2 imagery known as IRRISAT, and (iii) assimilating the canopy cover estimated by Sentinel-2 imagery into AquaCrop model. Sentinel-2 imagery proved to be effective for monitoring canopy growth of tomato crops in open field and for predicting irrigation water requirements during the mid-season stage of the crop, when the canopy is fully developed. The integration of the Sentinel-2 imagery with a crop growth model can improve the estimation of crop irrigation water requirement in the early developmental stage of the crop, when soil evaporation is an appreciable part of crop evapotranspiration. This study was part of the OPERA project, financed under the ERA-NET Cofund WaterWorks2015 Call.