Energy consumption in barley and turnip rape cultivation for bioethanol and biodiesel (RME) production

Abstract The energy consumption for six spring barley ( Hordeum vulgare L.) production chains and five spring turnip rape ( Brassica rapa ssp. oleifera (DC) Metsg.) production chains were compared with each other and in relation to the energy content of the seed yield. Two cultivation intensities, standard and intensive production, were used for barley. Fertiliser production and grain drying were the most energy consuming phases of the chains. The production of nitrogen fertiliser alone accounted for 1/3–1/2 of the total energy consumption of the production chains. If barley were direct drilled and the yield stored in airtight silos, instead of drying, the energy consumption would decrease by 30–34%. Use of wood-chips instead of oil for grain drying would decrease the use of fossil fuel to the same extent. The input–output ratios for the intensive barley production chains were 0.18–0.25. They were somewhat lower than the ratios for the standard production intensity. The intensive production was more energy efficient despite higher input rates. The input–output ratios for turnip rape production were 0.32–0.34. The energy consumption for manufacturing, repair and maintenance of machines and buildings requires more research because it is a significant factor but the data available are largely old and few studies have been conducted.