Application of thermal analysis techniques in soil science

Thermal analysis techniques have long been used in the study of soils, particularly in clay mineralogy. While there exists a large volume of literature (including several books) on the theoretical underpinnings of thermal analysis and its application to the analysis of minerals, the exothermic reactions associated with the thermal oxidation of soil organic matter have received much less attention. The proposition that soil thermograms represent characteristic properties and can be used to characterize soil organic matter quality has existed for decades. However, only recently has the number of tested soils and fractions been large enough to test this proposition and the potential link between thermal and biological soil organic matter stability. Due to the increasing demands for rapid and quantitative assessments of soil organic matter quality, thermal analysis techniques are a unique means to characterize the complete continuum that comprises soil organic matter. The interpretation of thermal analysis results must, however, go beyond the qualitative and therefore requires careful attention to analytical parameters and post-analysis data manipulations. The objectives of this review are to summarize the historical development of the application of thermal analysis techniques in soil science, and to present the emerging application of thermal analysis for the characterization of soil organic matter.