Comparative life cycle assessment of three representative feed cereals production in the Po Valley (Italy)

However, according to the environmental results, the selection of the best biomass source depends on several methodological assumptions such as the functional unit and the allocation criteria considered (between the grain and the straw) as base for the calculations. Thus, the results of a sensitivity analysis showed that the choice of a mass allocation instead of economic one caused lower environmental impacts in all the categories. Moreover, the consideration or not of the environmental burdens related to the digestate production (the main organic fertiliser used) was also a critical step in the environmental evaluations. The inclusion of environmental loads related to digestate production caused a notable increase in the impact of all the cropping systems regardless the cereal and the impact category. This conclusion could be extrapolated to other systems that exclude the additional burdens allocated to the production of organic fertilisers.