Sensoriamento remoto suborbital de alta resolução no monitoramento do desenvolvimento vegetativo em cana-soca irrigada

Abstract

Sugarcane plays a fundamental role both for society and for the economy, and Brazil is the first producer in the world. Irrigation has been an important tool to guarantee the growth and production of sugarcane. Remotely Piloted Aircraft – RPAs have been considered excellent allies in high-resolution remote sensing for crop monitoring, using indices such as NDVI mapping, which is a method for classifying the vegetation cover of the crop. Thus, the objective of this research was to monitor, through high-resolution remote sensing, the spectral response and the development of the sugarcane crop, in three irrigation regimes, in the Zona da Mata Paraibana region. The study area was a sugarcane field belonging to the Japungu Agroindustry (6°53'5.32” S;35º2'5.52” W), consisting of three experimental plots with different irrigation schedules: 40, 60 and 80 mm monthly. A meteorological station provided the data for environmental characterization and fortnightly flights were performed with an ARP Phantom 4 RTK carrying a multispectral camera for mapping the NDVI. As a result, NDVI was effective in the vegetative monitoring of the sugarcane plantation. The highest values of NDVI were registered in the phase just before flowering and, in this stage, NDVI had a decline. No expressive difference was found in the NDVI between the irrigation plots, although in the 40mm schedule the lowest NDVI values were recorded. Other factors, such as the precipitation and insect’s attacks, may have caused variability in the NDVI, despite the water regime that the crop was suffering. Thus, more studies are needed to reach precise conclusions about the response of the index according to the irrigation supplement received, under the study conditions.