Effect of Variable Rate Seeding and Fertilizer on Yield and Spectro-Temporal Behavior of Bean Crop
摘要
The application of variable rate inputs and the monitoring of crops through remote sensing can assist in increasing yields while making rational use of increasingly scarce natural resources. To assess the effect of variable rate application of seeds and fertilizers on yield and spectral-temporal behavior, 28 orbital images from PlanetScope CubeSats were selected at the key phenological stages of common bean cultivation. Seed and fertilizer recommendations were based on the cultivar used, soil analysis, historical yield data for the area, and soil electrical conductivity. Spectral-temporal profiles of vegetation indices (VIs) were generated to identify changes in spectral response throughout the crop cycle, and correlation analysis was conducted between VIs and bean grain yield at different phenological stages. Variable rate seeding and fertilization did not significantly influence bean yield, with average values ranging from 1564.52 to 1922.45 kg ha−1, exceeding the national average but falling below the average for the Northwest region of Minas Gerais. Significant correlations between yield and spectral response were observed during pod filling (R8) and maturation (R9), with maximum correlation values reaching 0.53 between NDVI and SAVI and yield at 80 DAS. The study did not find a significant influence of different seed and fertilizer distribution rates on bean yield; however, the results suggest that, even in the short term, variable-rate input distribution can optimize their use, reducing environmental impact and production costs.