Correlation between corn leaf spectral reflectance and leaf total nitrogen and chlorophyll content under different nitrogen level

The correlation between the corn leaf chlorophyll content,total nitrogen content,moisture content and leaf spectral reflectance was studied in a patted experiment under different N treatments.Results showed that shooting stage and trumpet stage were sensitive stages for diagnosis of nitrogen in corn.The precision of inferring leaf nitrogen and chlorophyll concentration by leaves maximal spectral reflectance at green waveband was:trumpet stage shooting stage anthesis-silking stage.Different wavebands should be chosed for diagnosis of corn leaf nitrogen and chlorophyll concentration in different development stages.It was proved that the reliability of using visible spectral reflectance was preferable than other wavebands at shooting stage and trumpet,but near infrared spectral reflectance was more reliable at anthesis-silking stage.The combination spectra variables of two wave bands were better than single wave band to estimate the content of leaf total nitrogen and chlorophyll.