Environmental impact of energy crop cultivation

Crops cultivated as feedstock for energy conversion processes (energy crops) could cover about 5% of the total energy demand of the European Union. Therefore, cultivation, harvest, processing, and finally utilisation of feedstock are required to be sustainable minimising environmental pressures and maximising environmental benefits. This contribution will give a comprehensive view on the environmental impacts of cultivating conventional energy crop species like cereals, rape seed and maize and of the hitherto uncommon species such as willow and poplar. Generalisations of environmental relevant parameters are deduced based on literature surveys as well as on results from own long-term experiments at Leibniz-Institut fur Agrartechnik institute. These parameters include biomass yield and energy yield, demand for water, fertiliser and pesticides as well as other environmentally relevant substances, emission of nitrous oxide and depletion and enrichment of soil carbon. In addition, recent results regarding energy balances and CO2-balances are presented and discussed. It can be concluded that energy crops specified for ligno-cellulose utilisation are preferable to oil, sugar and starch containing crops. In the first case the whole plant biomass can be used. Furthermore, biodiversity is increased and nitrogen demand and nitrous oxide emissions are decreased. Finally, in context with conventional and especially future energy technologies it is possible to obtain high CO2-mitigation potentials.