Low efficiency in the use of nitrogen fertilizer, has been reported around the world which often times result in high production costs and environmental damage. Today, unmanned aerial vehicles (UAV) cameras are being used to obtain conditions of crops, and can cover large areas in a short time. The objectives of this study were (i) to investigate N-variability in wheat at early growth stages using induced fluorescence indices, NDVI measured by active sensor and NDVI obtained by digital imagery; and (ii) understand the relationship among the various indices in explaining N-variability. The experiment was conducted in a greenhouse, and the experimental block design consisted of six replications. The treatments were composed of five levels of nitrogen (0, 25, 50, 87.5 and 150% of N recommended in Hoagland solution). Wheat seeds were planted in 30 pots with 6 kg of silica sand. The first application of N treatments was applied to the pots with 300 ml of water with different N levels at three days after emergence (DAE). Second application of N treatments was performed at 15 DAE. Sensor measurements were acquired at 24 and 28 DAE. The four sensors used in this study were Mutiplex3 (FORCE-A, Orsay, France); NDVI by Trimble Greenseeker handheld; and NDVI estimated from images obtained with two cameras (Gopro Hero4 InfraRed and Canon SX280 InfraBlue). Considering the results we conclude that nitrogen balance index estimated from fluorescence and NDVI by Greenseeker as well as NDVI obtained by digital images of GoPro camera with Red-IR filter have potential for fast and easy detection of nitrogen variability at early growth stages of wheat crop. Field research should be carried with wheat and other crops to enable the use of NDVI obtained from photographic equipment embedded in drones, to diagnose nitrogen deficiency and recommend fertilizer application in varying rates in real time.