Diagnosis of Nitrogen Status in Rice Leaves with Canopy Spectral Reflectance

摘要

The investigation was made on the relationship of seasonal time-course canopy spectral reflectance and ratio index to total leaf nitrogen accumulation (leaf nitrogen content per unit ground area) in rice under different nitrogen treatments. The results showed there was a close correlation between the canopy spectral reflectance and total leaf nitrogen accumulation. Ratio of near infrared to green band (R_(810)/R_(560)) was linearly related with total leaf nitrogen accumulation, independent of nitrogen levels and development stages. Different datasets were used to test the linear regression equation, with average estimation accuracy of 91. 22%, RMSE of 1. 09 and average relative error of 0. 026. Thus, the ratio index R_(810)/R_(560) of canopy spectral reflectance should be useful for non-destructive monitoring and diagnosis of nitrogen status in rice plants.