The Relation of Paddy Rice Canopy Spectrum Reflectivity and the Leaf Moisture Content in the Different Nitrogen Condition

The paddy rice canopy spectrum at a critical growth period is obtained by the use of ASD spectrometer. The relationship of leaf water ratio and canopy spectrum reflectivity in the different nitrogen condition is analyzed. The results showed that the relevance of the paddy rice canopy spectrum reflectivity and the leaf moisture content is less under the environment of lack of nitrogen. The correlation of canopy spectrum reflectivity of waveband between 736 nm and 1350 nm and leaf moisture content is up to above 0.7 under the environment of right nitrogen amount. The correlation of canopy spectrum reflectivity of waveband between 730 nm and 1300 nm and leaf moisture content is above 0.5 under the environment of excessive nitrogen. The sensitive bands corresponding to paddy rice moisture content are selected, and the ratio vegetation indexes of different growth stages are analyzed. We can find that, at the heading stage, the relevance of R1000/R740 ratio and the moisture content of leaves is best without the influence of nitrogen fertilizer processing. A regression model is set up and the correlation coefficient reached 0.89, and the standard error is 0.0197.