The relative contribution of applied inputs of rapeseed (Brassica napus L.) agro-ecosystem on environmental factors

In this study, the environmental impacts of rapeseed production were stud-ied using the SimaPro software. The initial data were collected from 30 farmers in the Alborz Province by face-to-face questionnaire method. The selected functional unit (FU) was one Mton-1 rapeseed production. Five en-vironmental indices were evaluated, including the potential of abiotic de-pletion, acidification, eutrophication, global warming and ozone layer de-pletion. To produce each ton of rapeseed, 84 kg of nitrogen, 63 kg of phos-phate, 63 kg of potassium, 133.5 l of diesel fuel and 586 kW of electricity were used. Also, the CO2, CO, N2O and NOX (different types of oxides of nitro-gen) emissions were about 361, 4.1, 11.5 and 4.8 kg per ton of rapeseed re-spectively. The results indicate that the global warming potential amounts to 1629.52 kg CO2 eq. Also, the acidification and eutrophication potentials were found to be 8.31 kg SO2 eq. and 2.73 kg PO4 eq. respectively. It was also revealed that the chemical fertilizers had the highest contribution among the evaluated inputs within the rapeseed growing period. Overall, this study showed that reducing the consumption of chemical fertilizers, especially nitrogen-based ones, is important for reducing environmental footprints in rapeseed production.