ANALYSIS OF THE PERFORMANCE OF WINTER CEREALS BY YIELD MAPS AND THE NORMAL DIFFERENCE VEGETATION INDEX (NDVI) IN THE SOUTH WEST AREA OF BUENOS AIRES, ARGENTINE

Abstract

The emergence of global position systems (GPS) combined with yield monitors (MOR) provide the opportunity of mapping yield during harvesting. The images from the MODIS sensor (MOD 13 Q1) could be used in precision agriculture (AP). It is interesting to evaluate the relationship between yield maps (MR) and normalized difference vegetation index (NDVI) in winter cereals in the SW of Buenos Aires (SOB), in order to provide preliminary experimental data for future research on AP. The objectives of this study were: a) To filter data collected from combine harvesters equipped with GPS and MOR in order to obtain MR; b) To determine NDVI for dates close to flowering in wheat and barley in the experimental area; c) To identify areas with variations in wheat and barley yield based on data collected from season; d) To correlate MR and NDVI images. The study was conducted in two fields located in the district of Coronel Dorrego. Crops of bread wheat (Triticum aestivum) and malting barley (Hordeum distichum) cultivated under direct planting system were used. A significant regression was observed between MR and the NDVI with r2 values of 0.84 and 0.75, recpectively, so that in situations when MR were not available, the NDVI could be used. Five areas with important variations in wheat and barley yield were identified in the experimental area.