Maize as far as the eye can see: approximately ten years ago, Germany experienced a biogas boom that left vast stretches of land covered with little more than maize. This was due to the fact that the Renewable Energy Sources Act (Erneuerbare-Energien-Gesetz, EEG) promoted biogas plants in which the feedstock is often maize. The aim was to convert the biomass growing in the fields into electricity so as to reduce dependence on fossil carbon sources such as lignite.
However, the maize and rapeseed fields planted for biodiesel production had undesirable ecological consequences; they became a paradise for rats and wild boars, and the hog population literally exploded. According to the Wirtschaftswoche 2011, damage caused by wild boars quickly amounts to 1000 to 2000 euros per hectare. In addition, the cultivation of biogas maize competes with feed production and pushes up the price of farm tenancy.