USO DE SENSORES PORTÁTEIS E IMAGENS AÉREAS NA AVALIAÇÃO DO ESTADO NUTRICIONAL NITROGENADO NA CULTURA DO MILHO

Abstract

In Brazil, as it is a tropical country and requires high nitrogen demands to increase corn productivity, attention is drawn in ways to improve nitrogen management for crop. Thus, in the first study, the objective was to validate the use of Dualex sensor ("dual excitation") for corn cultivation. In this way, it was evaluated five areas with five different doses of nitrogen (N) to create a chlorophyll gradient that would allow validating the Dualex sensor in comparison with the SPAD (Soil Plant Analysis Development) sensor. In the second study, the objective was to use a Red Green Blee - RGB camera coupled to a Remotely Piloted Aircraft System (UAV) to verify if it is possible to observe the different chlorophyll gradients in three different cities. Among the clip sensors, the use of Dualex presented a correlation with SPAD of 88 to 92%, which shows that Dualex is a sensor that can be used in corn crop to estimate chlorophyll. Among the ways to assist in the nitrogen management in corn crop, there are other possibilities besides Dualex and SPAD, which would be the use of UAV coupled with low-cost cameras (RGB) to assist this management in large areas. After the methodology, a mathematical calculation was generated using all the values of the 3 bands in the 3 municipalities and it was concluded that the combination of the Green and Blue bands in the equation 68.65 + (0.36*(Green+Blue)) can estimate up to 66% of nitrogen present in the corn crop. Portable and remote sensors proved to be a tool that achieves good correlations with the amount of chlorophyll present in the corn crop and, therefore, can be efficiently used in nitrogen management.