The labile Carbon as indicator of changes in two soils under different uses

Abstract

The soil organic matter is an essential component in the reserve and carbon cycle. The carbon in the soil is incorporated to the continuous contribution of organic material in natural conditions, however, the land´s practice generates the organic carbon decrease while sustainable practices of land use contributes to its capture and accumulation. A frequent practice for evaluating changes of the organic matter quality under different managements is the determination of labile fractions of soil organic carbon. The content of Labile Soil Organic Carbon (COSL) was compared on the soil layer 0-20 cm of a soil Ferralítico Rojo Típico from Ciego de Ávila with a Ferrítico Rojo Oscuro from Camagüey were undergone to three uses of the soil: Without exploitation, diversified and intensive crop cultivation. COSL extraction was performed by oxidation with potassium permanganate (0,02 mg L-1) and the determination was made by colorimetry. Independently the use, the content of COSL
is higher on the Ferralític soil than on the Ferrítico one but in both the contents decreased in the areas under intensive cultivation in relation to the ones without any exploitation. In addition to this, in the diversified systems, based on Lands Sustainable Management, this indicator tends to recover. These results suggest the inclusion of the determination of the COSL, as an alert indicator on how the soil´s uses affect the quality of them.