High accuracy site-specific secondary data for mechanical field operations to support LCA studies

INTRODUCTION • Agricultural operations are strongly influenced by site-specific pedological and climatic working conditions. The use of the same machine in different site-specific conditions, as well as the performance of the same operation in equal site-specific conditions (but with different machines), strongly influence the environmental costs of the operation itself; • Methodologies to quantify the environmental impacts of mechanical field operations are widely applied, but, usually, system inputs and outputs come from international databases or literature and rarely represent the studied situation. GENERAL OBJECTIVES • To quantify site-specific secondary data related to mechanical field operations in EU cereal cropping, from primary soil tillage to grain and straw transportation, paying particular attention to barley; • To use this environmental inventory to perform the LCA analysis related to barley cultivation in EU. RESULTS and DISCUSSION Fuel consumptions – and the corresponding emissions into the atmosphere – strongly depend on both tractor’s engine loads and duration of each working time: the assumption of a constant engine load (maximum value) for each working time – and thus a constant specific fuel consumption – leads to wrong evaluations in terms of fuel consumptions and emissions; • BarNow inputs amounted to: fuel FC = 67-74 kg·ha-1, lubricants LC = 0.56-0.73 kg·ha-1 and mass MC = 7.9-8.8 kg·ha-1. Emissions of CO2 amounted to EMCO2 = 211-233 kg·ha-1. BarPlus inputs amounted to: FC = 55-60 kg·ha-1, LC = 0.54-0.69 kg·ha-1, MC = 7.2-8.0 kg·ha-1 and AdB = 2.8-3.0 kg·ha-1. EMCO2 = 173-189 kg·ha-1. The highest fuel (and consequently CO2 emissions) and mass consumptions are, in any scenario, related to tillage operation.