Abstract

KLOSTER, NANCI; PEREZ, MICAELA  and  BONO, ALFREDO. Análisis del carbono total, orgánico e inorgánico en suelos de la región semiárida pampeana Argentina. Cienc. suelo [online]. 2016, vol.34, n.2, pp.365-372. ISSN 1850-2067.

The development of precise and accurate methods to determine carbon (C) in soils has currently a strong motivation due to agricultural and environmental importance of this element. In calcareous soils, the total C (C_T) consists of sources of organic (C_org) and inorganic (C_inorg) C. When are realized dynamics studies of soil C_org, a method to quantify it without interference from the inorganic fraction is required. In this paper, it was used the dry combustion method by the TruSpec CN (LECO) instrument for analysis of C_T, C_org and C_inorg and compared the results obtained with the classical method of wet oxidation for C_org and the titration method for C_inorg. The results indicate a low ratio (R² = 0.62) between the wet oxidation and dry combustion methods with all samples analyzed under study. However, this relationship improves when considering only samples with no carbonates (R² = 0.95). Thus Estimating C_org as the difference between C_T and C_inorg it could be an option in calcareous soils. Furthermore we evaluated simple titration and dry combustion method for determining C_inorg obtaining a high determination coefficient (R² = 0.99). Dry combustion method is not suitable for direct determination of C_org in soil samples with presence of C_inorg, being necessary the application of methods to differentiate carbon sources.

Keywords : Dry combustion; Wet oxidation; Simple titration.

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