The biogas potential ofJuncus effusus L. using solid phase fermentation technique

摘要

Wet grassland sites are often infested with Juncus effusus L. (soft rush). A high coverage of soft rush will lead to a restricted use in traditional animal-based farming systems. Therefore alternative options of biomass use are required urgently. Biogas production using solid-phase fermenters could be a promising alternative for the use of soft rush-infested swards. In our experiment, we varied the amount of soft rush (100% Juncus; 50% Juncus + 50% grasses and herbs; 100% grasses and herbs) in the substrate and analysed the substrate compaction. We then determined the methane production and a range of chemical and physical substrate parameters before and after anaerobic digestion. Methane yields ofJuncus (100%) were smaller than that of the accompanying grassland vegetation. The methane yield of the grass-Juncus-mixture was higher than expected from the energy content. We found that Juncus contributed to substrate stability and presumably to gaseous diffusion of methane through the substrate stock.