Demonstration of the Influence of Mg Vermiculite on the Activity of Cellulosic Agents and Diazotrophs During Composting of Lignocellulosic Residues

Adsorption and desorption properties, of a magnesian vermiculite (VMg), have been used to follow the dynamic of the NH₄+ ion ,which has been produced during the ‘cellulotytic-diazotroph’ association appeared during the aerobic fermentation of a mixture of wheat straw and poplar sawdust.This fermentation has been regularly followed for three months in a mini digestor, and temperature, ventilation, pH, humidity, and C/N ratio of macro-elements were controlled. The same is done for the associative activity of cellulolytics and diazotrophes (NUNTAGIJ, et al., 1989). However, if fermentation is not carried out under optimal conditions, there is a loss of ammoniacal nitrogen, and that often occurs during large scale composting of organic residues (MARTIN, 1991). Clay properties can be used to control this loss. Four types of vermiculites are chosen to do so: a natural vermiculite (VMg), an NH₄+ saturated vermiculite (NH₄+), a calcium and ammonium-saturated vermiculite, only in exchangeable position (VCaNH₄+) and a vermiculite having exchangeable oligoelements (VMgCaCuCoMnZn).