How composting affects heavy metal content

Recycling waste products through soil has gained increasing interest during the last decade. This trend has been accompanied by the development of a specific research activity concerning more detailed characterization of the different kinds of products. The presence and mobility of heavy metals have been shown to be of paramount importance for a correct evaluation of environmental hazards during their agricultural utlilization. Recent findings showed the importance of compost as a source of humified organic matter for agricultural soils. In general, the extractability and the distribution between specific forms varied widely. Concerning water soluable heavy metals, the occurrence of soluble forms was remarkable for most heavy metals. Differences found also seem to be related to the origin of the compost and sampling time. While technically very simple, the process of composting can bring about the production of substances of a good quality for agriculture.