Spectral Reflectance of Soils Derived from Mica-Rich Parent Materials in Two Different Toposequences in Relation to Soil Properties

The spectral reflectance of soils (<2 mm) of six pedons in two distinct toposequences was measured at eight different wavelengths in visible and near infrared regions of electromagnetic radiation. The overall distribution of reflectance decreased with slope in the first toposequence, while higher reflectance values were observed down the slope in the second toposequence, possibly because of changes in the nature/type of mica species together with significant contribution of organic matter and iron content of the soils. The contribution of organic matter to spectral reflectance was negatively significant throughout the spectrum. while the relationship of iron content was non-significant. The contribution of the lattice-K, which is mainly a function of the mica content of these soils, showed significant positive correlation with the soil spectral reflectance up to 550 11m. Soil reflectance had, however, shown definite relationship with soil colour in both the toposequences. Further, the values for correlation with sands were however, positive, while silts and clays had shown negative correlation throughout the spectrum. This seems to be interesting from the pedological point of view, since clays and silts are active soil constituent sun like sands to interact with organic matter and even with iron and thus increasing darker hue.