Using apparent soil electrical conductivity (EC_ap) and remote sensing to delineate soil sampling for precision fertilization in a vineyard

The intensification of agriculture has greatly enhanced crop productivity. However, it has also caused greater risk of environmental impacts, such as soil erosion and groundwater pollution. To maintain high crop productivity and reduce environmental emissions, natural resources use efficiency and nutrients recycling must be promoted. The present work aims to provide new insight on the spatial variability of soil chemical properties, particularly in a vineyard, in hopes of attaining site-specific management within a precision fertilization framework. This goal was achieved by establishing three different zones in a 6,77 ha parcel, according to remote sensing of apparent soil electrical conductivity (EC_ap) and normalized difference vegetation index (NDVI). In each zone, soil samples were collected in the row of vines, at different distances from the plant, and in the inter-row, at different distances from the row. Samples were later chemically described, and the resulting data was statistically analyzed. Using EC_ap and NDVI as tools in the design of distinct zones within a vineyard was highly effective, with most of the soil chemical properties varying at the highest significance level, as seen in the ANOVA test (p<0,001). The relationships between EC_ap and soil salinity (laboratory electrical conductivity - EC_1:2,5), EC_ap and exchangeable cations, and between NDVI and soil nitrogen (N) were evident in this case study. Further results showed that when the sample was collected directly in the row, the distance from the plant had no impact on the soil’s selected properties. However, when the sample was collected in the inter-row, the distance to the row significantly affected the selected soil properties. Overall, the results revealed potential for the implementation of site-specific crop fertilization and soil quality management.