Practical application of thermogravimetry in soil science: Part 2. Modeling and prediction of soil respiration using thermal mass losses

Properties and compositions of soils originating from different sources usually vary, depending largely on the conditions of soil forming processes and parent materials. Our previous investigations of soils from contrasting localities showed linear correlations between carbon dioxide produced by soil microorganisms and thermal mass losses of air-dried soils recorded using thermogravimetry. The correlations were observed at temperatures corresponding both to moisture evaporation and thermal degradation of soil organic matter. In this work, those soils were combined into one group and the correlation analysis was repeated using both linear and power functions. Whereas the linear dependency between respiration and water evaporation was confirmed; the connection between respiration and thermal decay of organic matter appeared to follow power function. These findings indicate the existence of fundamental unifying principles in soil forming processes, in terms of water binding and clay-dependent organic carbon sequestration, notwithstanding the fact, that soils develop under contrasting conditions. Additional soils were analyzed in order to test the applicability of obtained models for prediction of soil respiration using thermogravimetry. The results indicate a promising potential of this method mainly for soils originating from areas undisturbed by anthropogenic activity.