How much can regional agri-environmental measures contribute to SOC stocking in the soils of Sicily?

Soils have a great potential in stocking soil organic carbon SOC, but how much can human activities, and particularly agricultural ones, contribute to increase (or decrease) the SOC content? Which kind of agricultural practices are the most effective? From the soil database of Sicily we have selected 52 profiles, whose first 40 cm from the soil surface were analyzed for the SOC, of which 15 analyzed also for nitrogen N content, localized in the clayey hills and limestone marine terraces of the western Sicily, cultivated with grain crops and orchards (mainly olive groves and vineyards), surveyed and analyzed in a period from 1995 to 2008. By interviews to the farmers owners of those parcels,…