Study the Applicability of Sentinel-2 Optical Data, as Well as Benefits From the Sentinel-1 Sar Data, for Predicting the Yield of Organic Barley

The barley crop is widely used in the economic life of humanity and is characterized by great ecological plasticity. It is a good competitor to other cereals, which is why it is extremely suitable for growing in organic farming. The multispectral data obtained from the COPERNICUS Sentinel-2 satellites has proven in numerous scientific works its applicability to support crop monitoring. In that way, that data is invaluable in optimizing the production processes. In this study, a comparison was made between satellite data products derived from the COPERNICUS Sentinel-2 optical and Sentinel-1 SAR data, as well as studying their statistical relationship with the yield of the organically grown barley. The spatial resolution of all products is 10 m. The utilization of both satellite data types for monitoring and forecasting the yield of organically grown barley has been verified. The BBCH-41 phase was found to be the most suitable for the utilization of Sentinel-2 optical data to generate a different set of vegetation indices for yield prediction. In that phase, most of the tested vegetation indices showed successful yield prediction. The most relevant is the Green Chlorophyll Vegetation Index (GCVI; r = 0.80), which has the highest correlation with the yield. Considering SAR data, the backscatter in co- and cross-pol were derived in terms of Sigma-Nought. The Radar Vegetation Index in dual-pol (dRVI) was also calculated. As reported in other studies, a correlation is observed between dRVI and vegetation indices (e.g., NDVI). Whole output SAR products are sensitive to the geometrical properties of the crop and represent in various extent the phenological development of the organic barley. In this regard, SAR data complements optical data and provides reliable information on crop conditions during periods of high cloud cover. Bearing in mind that very often these periods coincide with phenological phases that are critical in crop development.