Use of digital images for evaluating soil compaction in the culture of beans

bean yield in brazil is considered low, around 820 kg ha-1, reaching values above 3000 kg ha-1, there are several environmental factors which may limit the performance of this culture, especially those related to the soil. the present work aimed to evaluate soil compactions in bean culture of different soil management systems, by means of digital images. this study took place at the federal university of vi？osa, randomized block design with six replications was used and four treatments, (direct planting, conventional preparation, minimum plantation using grade crusher-leveler and minimum plantation using scarificator), were evaluated. the spectral responses using the vegetation indexes (ndvi, rs, gndvi, vari, wdrvi and savi) were evaluated, calculated from digital numbers of the images and the values were estimated from the reflectance. for obtainning the images, a platform containing two digital cameras, one sensitive in the region of visible (rgb) and another sensitive to the region of proximal infrared were used, this platform was attached to a helium-inflatable balloon. the vegetation indexes obtained from the values of digital numbers of images were only able to defer treatments 70 days after plantation. however, indexes obtained from the reflectance, deferred treatments at 34 and 70 days after planting.