Hyperspectral characteristics and estimation of organic matter contents of different soil types in North Xinjiang

The hyperspectral characteristics of four soil types(Light chesthnut soil, Cold calcic soil, Calcic chernozem,Gypsum gray-brown desert soil)in North Xinjiang and their relationship with soil organic matter content(SOM)were studied.The results showed that the spectral reflectance of Calcic chernozemwas significantly lower than other soil types.Negative correlation between the spectral reflectance and SOMwas detected as SOMwas higher than 14 g·kg- 1.By contrast, positive correlation existed with lowSOM( 8 g·kg- 1). Correlation analysis of spectrum reflectance with SOM indicated thatSOM correlated with the spectrum reflectance in 593.6 nm band, in 661 nm band by removal of the envelope of reflectance, and in 547.4 nm band through first-order differential of reflectance. In addition, the prediction accuracy of the first-order differential was relatively high, and thus can be used in the estimation SOM of mainly soil types in North Xinjiang.