Utilizzazione di digestati anaerobici di matrici organiche come ferilizzante nel vivaismo.

The increase of peat demand for horticultural crops, the reduction of peat availability, due to more and more restrictive regulations about the peatland exploitation and the increasing ecological awareness about the sustainable ecological development, has producted the necessity to find other materials that could replace, totally or partially this product as root substrates. It could be interesting to substitute peat with cheaper renovable products, using rejecting items considered as a cost for the company. Several scientists have already started to characterize, chemically-physically, the rice hulls and anaerobic digestion residues as peat substitute. Rice hulls is a by-product in rice processing composed by bracts that are removed from paddy during rice processing. The extensive world-wide use of rice presupposes that this rejected products are available on the market constantly and at a low cost. Petroleum exhaustibility and the costs of agricultural-industrial wastes obliged XXI century man to better use natural resources exploiting also what was, till than, considered a rejected product. Anaerobic digestion process has changed rejected products into source of energy, producing a byproduct: anaerobic digestion residues which could be used as agricultural amendant. The object of the thesis is the chemical-physical characterization of mixtures of different combinations of peat, rice hulls and anaerobic digestion residues derived from fruit pomace to consider the possibility to use them as substrates in horticultural cultivations. The results demonstrated that the substrates with percentage of 67 and 100% of rice hulls are not right for cultivation because they present physical features too far from those considered adequate. If the rice hulls are ground, air filled pore space and water holding capacity of substrates are acceptable even if with high rice hulls percentage. The addition of anaerobic digestion residues increased the content of nutrients and this could be an advantage in substrates production for cultivations. The several observed interactions among the chemical characteristics make difficult to chemically evaluate these substrates.