Soil Fertility Status Assessment Using Hyperspectral Remote Sensing

Information about NPK content in farm soil is important for further application of the necessary dosage of fertilizer. At present, laboratory-based chemical analysis is being used to assess the status of soil nutrients, but these methods are complex, tedious, costly, and poor in in-situ condition. While, for precise farming, in-situ assessment of soil fertility status is of prime importance. Hyper-spectral remote sensing bears the potential of a detailed investigation of soil through analysis of its spectral absorption features. Therefore, this study aims to estimate quantitatively the content of fertilizer in a sample of soil making use of spectral properties of macro soil nutrients. For addressing the above-mentioned issues, this study has used Derivative Analysis for Spectral Unmixing (DASU), approach consisting of spectral unmixing and spectral derivative analysis. The study reveals that the spectral region 993.2nm provides a unique feature. It leads to the development of a model for estimation of NPK fractional abundance in a soil sample. Further, this model has been validated for the good number of soil samples in a laboratory. Thus, the key contribution of this study is to underpin that; the hyper-spectral remote sensing may be used in-situ to estimate soil fertility of farm soil. Although, the fractional abundances of individual components of NPK may be considered as future scope of work.