Vegetation index as a tool for monitoring soybean yield in Center-South region of the state of Parana - Brazil

Abstract

Crop monitoring is an important tool for agricultural management. Soybean is one of the most important crops in Brazil because it can be used as food and has an important role in the economy, especially in the Center-South region. The most common methods to monitor crop yield in Brazil are based on interviews and questionnaires made by the official organizations and answered by the producers. As an alternative to monitoring large areas, remote sensing data has shown the potential to improve crop yield monitoring. The objective of this study was to evaluate the applicability of using vegetation indices to monitor soybean yield in the Center-South mesoregions in the state of Parana. For this, we used Sentinel-2 imagery from 2019 and 2020 to calculate vegetation indices (NDVI, NDWI, EVI, and SAVI) and the soybean yield from the Brazilian Institute of Geography and Statistics (IBGE). The vegetation indices and soybean yield were correlated using regression analyses. The results were compared with the traditional methods generated by IBGE. Based on the vegetations index used, the EVI and NDWI had the best correlation with the soybean yield. Studies using more extensive time series analyses in different regions are necessary to evaluate which of the vegetation indices are better for monitoring soybean yield to achieve sustainable crop management and production.