Agricultural production contributed 60% of the carbon footprint, mainly from the use of nitrogen fertilizers. GHG emissions of root production varied widely due to (1) the diversity of farming practices even within a small radius (50 km), and (2) different agricultural yields in different regions. The contribution of the factory stage to the carbon footprint depended on the use of electricity, biogas and other fuels, ranging from 217 to 342 kg CO2eq/FU. Allocation rules such as wet weight or dry weight basis allocations affected the results markedly