Spectral characteristics of organic soil matter: A comprehensive review

The information about the chemical composition of the soil is essential for agricultural, environmental, geological as well as in forensic science. The chemical constituents of soil could be revealed either by elemental methods or by spectroscopic techniques. The present review highlights the potential application of spectroscopic techniques, i.e., Fourier Transform Infrared spectroscopy (FTIR), Raman, UV–Vis-NIR, and laser-induced breakdown spectroscopy (LIBS) for the examination of spectral properties of soil samples which ultimately reveal its chemical makeup. This review explains various spectroscopic methods that are used for characterization and discrimination of soil based on organic matters; study on soil pollution, carbonates, etc.; and the principal finding of the studies are emphasized. Some lacunae in soil studies are still present in the literature. These lacunae are highlighted in the future challenges section in the hope to escalate the interest of researchers/readers of soil science.