The primary studies on the relationships between soil properties and canopy field spectra of rice in the Liaohe River Delta, P. R. China

Abstract

Through analysis of soil properties (Total salt content, pH and organic matter content) and measurements on canopy field spectra of rice, 27 paired-samples were gotten. The relations between canopy field spectra and the first derivative spectra of rice at milky-ripe stage and total salt content and pH of soil were discussed initiatively. Our results indicated that there weren't significant correlations between total salt content and pH of soil and canopy field spectra (the range of wavelength is between 350 and 1350 nm) of rice, and between total salt content and pH of soil and vegetation indices, and between total salt content and pH of soil and the locations and swings of red edges, but correlation between total salt content and pH of soil and the first derivative spectra of rice at milky-ripe stage is significant. Considering the first derivative spectra between 654 and 754 nm as the independent variables, 27 paired-samples were classified into three classes by the hierarchical cluster method. On the basis of the classification results, as the results of the Kruskal-Wallis H Test, total salt content and pH and organic matter content didn't clearly vary by the different classes. As the results of the Median Test method, total salt content had the difference between the three classes. However, there weren't the difference of pH and organic matter content as the classes varied. Finally, the linear regression models between the first derivative spectra and total salt content and pH were built.