The importance of soils in global change processes is recently becoming a major item of discussion. They play an important role as the source and sink of atmospheric CO₂, a main greenhouse gas, through the loss or accumulation of soil organic matter. Thus, to obtain further insight in the dynamics of litter and soil organic matter accumulation processes the development of methods which are able to follow decomposition of litter in soils are required. Advances in instrumentation and techniques that permit the study of dynamic processes in soil and structural determination of organic substances have provided new insights into the chemical composition and the role of soil organic matter in environmental processes. The development of FTIR methods for soil layers are reviewed and their application to environmental problems are discussed in this paper. The applicability of FTIR, either dispersive or transmission, to investigate decomposition and turnover processes of litter in soil originating from different forest sites in several climatic regions are summarized. A variety of bands characteristic of molecular structures and functional groups can be identified for these complex samples. Data analysis revealed that intensity changes of several bands of DRIFT and transmission FTIR were significantly correlated with soil horizons. The application of regression models enabled the estimation of soil parameters - such as organic carbon and nitrogen, - the identification and differentiation of organic forest soil horizons and allowed to determine the decomposition status of soil organic matter in distinct layers.