A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

Abstract

In a vineyard, plant water status variability is strongly dependent on soil spatial variability, whose physical characteristics drive the processes involved in the soil water balance. More the soil and its characteristics vary in space (horizontally and vertically), more the productive and qualitative vine performances will be non-homogeneous. In this context, the proximal sensing of apparent soil Electrical Conductivity (ECa) and its monitoring during the growing season can help to understand the nature of spatial variability of vineyard, supporting both viticultural microzoning (identifying Homogeneous and functional Homogeneous Zones, HZs and fHZs) and field experiments. The aims of this contribution are: i) to show how the use of proximal sensing of ECa in the identification of HZs is important, (ii) to show the added value of ECa monitoring during the growing season in order to identify the fHZs, (iii) and to highlight its importance in the evaluation of the experimental field treatments results in vineyard. The study was carried out in two rainfed commercial vineyards located in the southern Italy (Campania Region) cultivated with Greco (white) and Aglianico (red) grapevine variety. Over 2020 and 2021 seasons, detailed soil and atmosphere parameters were recorded, in-vivo plant eco-physiological monitoring has been conducted, and vine status spatial variability monitored by means of UAV multispectral images. Apparent soil electric conductivity (ECa) was measured five times for each vineyard during the growing season 2021 by using the PROFILER EMP 400 electromagnetometer both in vertical and horizontal dipole mode. This instrument allows to simultaneously work with three frequencies (5000, 10000 and 15000 Hz) and explore different depth of sub-soil. The recorded data were processed in MATLAB and compared with other recorded variables within GIS environment. The results have shown how the ECa can be a carries of information to support viticultural microzoning and experimental field data analysis.