Evaluation of Corn Nitrogen Nutrition Using Hyperspectral Remote Sensing

The hyperspectral reflectance for corn canopies were acquired in primary growth stages in order to monitor corn growth status and diagnose nitrogen. The results showed that the leaf nitrogen accumulation, vegetation indexes, area of red edge remarkably changed with growth stage. The leaf nitrogen accumulation almost increased from seedling stage to silking stage, and then decreased from trumpet stage to milky maturity stage. And vegetation indexes and area of red edge of corn canopy almost increased from seedling stage to trumpet stage, and then decreased from trumpet stage to milky maturity stage. The correlation analysis indicated that the spectral parameters highly correlated with leaf nitrogen accumulation at seeding stage, silking stage and whole growth stage. The correlation relationship of the whole growth cycle was stronger than that of any single growth stage. From a single stage point of view, the seeding stage was the best growth period to monitoring the leaf nitrogen accumulation. The regression analysis displayed that the all regression models between spectral parameters and leaf nitrogen accumulation were all significant at whole growth stage. The research demonstrated that it is a feasible method for quantificational evaluation of corn leaf nitrogen accumulation by hyperspectral remote sensing.