Browsing by Author "Kyttä, Venla"

Global growing demand to produce more food with less inputs and energy without causing greenhouse gas emissions challenges the current practice of using mineral fertilizers which are produced from new and partly non-renewable raw materials with considerable amount of energy. On the other hand recycled fertilizers made of different side streams and biomasses also need to be processed before usage or the amount needed per area is so great that the environmental advantages might be lost. The aim of this study was to discover and compare the energy consumption and greenhouse gas emissions of recycled fertilizers (ammonium sulfate, biogas digestate and meat bone meal) and mineral fertilizer in production of oat by using Life Cycle Assessment (LCA). All recycled fertilizers were found to cause less greenhouse gas emissions and consume less energy than mineral fertilizer. The least emissions caused the usage of ammonium sulfate and the best energy efficiency was achieved with biogas digestate fertilization. Considered relative to global increase in food and energy consumption and control of climate change and recycling of raw materials recycled fertilizers proved to be effective compared to mineral fertilizer. Also on the grounds of land use and yield recycled fertilizers turned out to be potential substitute for mineral fertilizers. Further studies are still needed due to large number of raw materials and constantly increasing amount of processing techniques of recycled fertilizers.