SATELLITE VS. GROUND-BASED MONITORING OF DURUM WHEAT BIOMETRIC AND PHYSIOLOGICAL PARAMETERS

Nowadays, the remote sensing technologies have been widely studied by many research programs. An evaluation and standardization of the available sensors is becoming a necessity after the increase of the sensors number and way of data acquisition for agricultural purposes. The aim of this study was to compare two remote sensing techniques (satellite and ground-based) as tools describing the variations of physiological and biometric parameters of durum wheat grown under different water regimes. The experimental layout was established in Policoro (Matera) located in Southern Italy about 3 km far from the Ionian coast. The growing season was from February to June with three distinguished water management practices (rainfed, 50% and 100% of irrigation requirements). The Landsat 8 images and radiometric ground-based data were acquired regularly in April, May and June together with plant biometric and physiological parameters. The overall results indicated no significant difference of biomass and yield for different irrigation regimes. This could be explained by large precipitation amount (205 mm) regularly distributed during the season which limited the needs for irrigation (105 and 52.5 mm for 100% and 50% irrigation, respectively). Soil adjusted vegetation index (SAVI) showed slightly better performance than normalized difference vegetation index (NDVI) when plotted against the leaf area index (LAI). The regression coefficient of such relationship was greater if based on the ground than on the satellite data. Therefore, it could be concluded that in site vegetation indices describe the LAI with higher fidelity than those from the satellite system. Nevertheless, the satellite data could provide reasonable indications about the crop growth when other means of measurement are missing.