Multispectral drone imagery as a tool for estimating nitrogen and chlorophyll content in Alfalfa Crops and its co-comparison with field results

The aim of this research is to evaluate the effectiveness of drone remote sensing in estimating nitrogen and chlorophyll levels in Alfalfa crops, and to compare it with traditional measurement methods. In parallel with this fieldwork, a systematic review of the literature in Web of Science and Scopus was carried out, yielding a total of 55 highly relevant articles, revealing that there is limited specific literature on alfalfa, but a great amount of methodological information. Results indicate that the effectiveness of vegetation indices varies according to the phenological phase of the crop. Significant differences were observed between nutrient levels in the upper and lower parts of the plants, with a higher concentration in the upper leaves due to better light exposure and greater absorption capacity.