ABSTRACT
The packing materials (Table 1) used for comparison were: (1) the nutritional synthetic material UP20 containing CH4N2O, H3PO4, CaCO3 (C/N/P molar
ratio: 100/5/1) and an organic binder (20% in mass) from Elotex industry. The dimensions of granules are 7 mm in diameter and 15 mm in length; (2) a mechanically crushed sapwood (Hortifibre®) which is a cheap material composed of 100% of wood fibers from cultivated forests. Sapwood looks like fibrous wood stick of 1 cm long and 2 mm diameter; (3) pine bark, chosen for its good physical properties (low bed density) and very low price; (4) pozzolan, which is a volcanic siliceous rock, inert and relatively cheap. Pozzolan used was mainly composed with SiO2 (44%), Al2O3 (15%), Fe2O3 (15%) and CaO (10%) and appeared as irregular spherical beads with diameters ranging from 5 to 10 mm; (5) a fibrous peat purchased from “S.A. La Florentaise Company”. Elemental analysis of the peat was C: 50.2%; H: 6.0%; O: 33.0%; N: 0.8%.
