"Monitoring and validation of the use of remediated sediments as a substrate for plant nursing and cultivation: non food crop production". "Physical, chemical and biochemical properties of the growing media". Deliverable Action C.2.3

The sediments constitute a very difficult substrate to insert in agronomic and horticultural contexts due to their geomorphological characteristics and contamination, in particular the bulk density, the clay component and the generally low carbon content constitute qualities that make their use in these context difficult. In the Subsed project, various percentages of the recovered sediment were tested in specific growth substrates for each type of cultivated species. The substrates were chemically, physically, and biologically characterized at the time of their preparation and after the growth of the plant species of interest. Specifically, the substrates have been used for the growth of Prunus laurocerasus (laurel), Zantedeschia aethiopica (calla) and Protea cynaroides (protea).The chemical-physical parameters required by Legislative Decree 75/2010 are satisfied by all the tested mixtures. The substrates used in the experimentation with protea, both peat-based and coconut-based mixtures, exceed 4% TOC showing the highest values in substrates subjected to more restrictive water regimes (R2). All heavy metals are below the limits required by Legislative Decree 75/2010 Annex 4 for mixed growing media. Changes in physical and chemical parameters reflected the substrate-plant interaction, such as the increase soil organic carbon, due to the release of root exudates and the presence of plant remains. The increase in the biological activity of all substrates demonstrates how the interaction between substrate and plants has had positive effects on the biological quality of the substrates itself.