Impact of a Cultivation System upon the Weed Seedbank Size and Composition in a Mediterranean Environment

Abstract

The knowledge of the soil seedbank is crucial to predict the dynamics of weed communities and potential future problems in agroecosystem weed management. Therefore, the aim of this study was to evaluate the qualitative and quantitative variation of the potential and real weed flora as a function of different cultivation systems (namely organic, conventional and uncultivated) in a Mediterranean environment (Sicily, south Italy). The results proved that soil seedbank density was significantly different in superficial (0–10 cm) and deeper soil layers (10–15 cm) in both organic and conventional cultivation systems. Portulacaceae and Amaranthaceae were the dominant botanical families, although they achieved a higher total number of seeds m−2 under a conventional cultivation system than under organic and uncultivated ones. The whole weed flora was represented by 45 taxa, but the presence of the crop reduced the qualitative and quantitative composition of real weed flora. In conclusion, the knowledge of the seedbank size and composition, as well as the variation in time and space of real flora, may contribute to predict the dynamics of weed emergence and their possible interference with crops. In particular, information on the weed dynamics is essential to develop sustainable control protocols, especially under organic farming.