Nitrogen fertilization assessment in maize (Zea maysL.) using hyperspectral UV/VIS/NIR data

ABSTRACTIn this study, we are identifying differences in the UV/VIS/NIR (ultraviolet/visible/near-infrared) spectral signatures of maize leaves according to a range of fertilization rates from 0 to 240 kg/ha. By utilizing a FieldSpec spectrometer, it was determined that the spectral response displayed significant differences (p-value = 0.05) under the influence of nitrogen fertilization within the following ranges: near ultraviolet: 355 nm (±5 nm), visible light (green): 550 nm (±15 nm, wide band); 555 nm (±5 nm, narrow band), red edge: 720 nm (±20 nm), infrared: 1075 nm (±50 nm); 1380 nm (±20 nm). Based on the estimated differences, two remote sensing indicators for maize during the 5–6 leaf growth stage and nitrogen fertilization were developed: (NIR-RED_EDGE)/(NIR+RED_EDGE) and (NIR-GREEN)/(NIR+GREEN) where NIR is 1075 nm band, RED_EDGE is 720 nm band and GREEN is 550 nm band. These indicators determined the level of fertilization with a coefficient of determination R2value greater than 0.85.