Thermal stability of soils and the detection of use-induced changes Artikel uri icon

Open Access

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Peer Reviewed

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Abstract

  • Several investigations on soils are currently focused on sustainable land use. However, there are still no common laboratory method to distinguish soils from carbon containing substrates (CCS). This makes the detection and evaluation of use-induced soil changes not easy. We tried to fingerprint natural soils using thermogravimetry. The goal was to create a reference base for easier detection of use-induced soil changes with a simple detection method. For this purpose, over 150 samples under natural vegetation were collected and analysed from natural parks, biosphere reserves and other protected regions in US, Europe, South America and Russia. Using different statistical approaches, it was not possible to directly derive common characteristics of natural soils from peaks or curves from thermogravimetric data. But, the thermal mass loss allows a reliable detection of organic carbon, nitrogen, clay and carbonates in soils with high accuracy [1]. Further, typical relationships were found to exist between mass losses in distinct temperature areas in soils under natural vegetation. For example, nearly all natural soils characterised by a correlations between mass losses around 125 degrees C and 525 degrees C with high coefficient of determination (0.7 - 0.9). This correlation can easily be explained by the long term influence of clay minerals on water sorption (mass losses around 125 degrees C) and on accumulated of humic substances [2] (mass losses around 525 degrees C). In contrast, CSS are usually a result of shorter time periods or prevalence of non biotic processes. Additional water binding by plant residues can modify mass losses around 125 degrees C and disturb the correlation. At 525 degrees C the decay of black carbon has a similar effect. Further investigations should clarify to what extend the correlations found in natural soils can be used to distinguish soils from carbon containing substrates and to detect influences of cultivation, fertilization and other land use technologies.

Veröffentlichungszeitpunkt

  • Januar 1, 2011