Uniformidade de vazão, índice de vegetação normalizada e produtividade da cana-de-açúcar sob irrigação por gotejamento.

Abstract

Given the importance of irrigating agricultural crops, it is necessary to determine the uniformity of water distribution to ensure the quality of irrigation, frequent monitoring of irrigated areas must be carried out in order to observe the dynamics and conditions of cultivation. In view of this, the present work was developed with the objective of evaluating the quality of irrigation of sugarcane at Usina Vale Verde - Baia Formosa. The study was carried out between February 2021 and February 2022, at Fazenda Pedrosa, belonging to Usina Vale Verde and located in the municipality of Bahia Formosa-RN. A total area of 15 ha was used, subdivided into five sectors of 3 ha each. At the end of the sugarcane cycle, for each of the sectors, the irrigation system flow uniformity coefficient (CUD) and crop productivity were determined. In addition, in six seasons throughout the crop development, the mapping of the Normalized Difference Vegetation Index (NDVI) of the soil cover was carried out, through the QGIS software, using Sentinel-2 satellite images made available by the spatial database of the United States Geological Survey (USGS). The NDVI determination was performed by the ratio between the reflectance difference of the near infrared (band 04) and red (band 08) bands, under their sum, the NDVI images were classified according to the vegetation cover density in phytophysiognomies. After evaluating the data obtained in the present study, it was found that the CUD values have a direct correlation with the productivity of the place, as well as the NDVI images showed higher values in the areas of greater CUD and productivity, thus, the CUD and NDVI are important variables as a source of information in decision making in improving irrigation quality.