Variation of organic matter content in Maltese soils after a 15-year period

Abstract

The aim of this study was to evaluate temporal differences in SOM levels in six specific plots around Malta that were originally investigated in 1997. The sites chosen have been either uncultivated or cultivated for the past years and have contrasting soil characteristics. SOM is a significant indicator of soil quality not only economically, as it enhances plant productivity, but also for C sequestration and biodiversity. It also determines the soil's biological activity, which has a major impact on its chemical and physical properties. Soil sampling was carried out during the winter season from the top 5 cm and from a depth of 15-20 cm. Five sub-sites were sampled from each plot in order to obtain a representative sample of the soil within that plot; particularly in view that Maltese soil types can vary even within the same field. OM content, was determined with the wet oxidation method. In the majority of the plots, the difference in OM between the soil sampled in 1997 and 2012 was not significant. Only two sites exhibited a significant difference.