Evaluation of soybean condition under various fertilizer application by the relationship of the red and near-infrared bands reflectance in scatter plot

Abstract

This study aims to determine the dependence of the red band reflectance and near-infrared band reflectance in the evaluation of crops. The experiment using various fertilizers on soybean crops was analyzed to show the difference in reflections of red and near-infrared wavelengths. We used a multispectral camera attached to a UAV to obtain reflectance data of the surface. In this study, we used the normalized difference vegetation index, calculated based on red and near-infrared bands. The lower the value of red reflectance and the higher of near-infrared reflectance, the more chlorophyll, healthy vegetation, and the higher the crop condition. The decreasing photosynthesis rates and changes in leaf mesophyll are usually associated with decreasing reflectance of wavelengths within the near-infrared spectral range. We processed the obtained images and data from the camera and analyzed the reflectance separately for each plot of the surveyed field and each pixel of the image. The results showed in this paper that, according to a scatter plot analysis, different pixel concentrations were noted, which indicated by different information on the test field plot.