Cradle to farm gate life cycle assessment of oilseed crops production in Iran

The goal of this research was to evaluate the environmental effects of the production of soybean (Glycine max), sunflower (Helianthus annuus L.), and canola (Brassica napus) oilseed crops in Ardabil in Iran. Lifecycle assessment was conducted to compare environmental burdens, water demand, and land use of these three crops. Four categories of environmental impacts were used to define in this method. The categories are eutrophication, acidification, global warming potential, and photochemical oxidation. Additional categories were water dependence and land use. These environmental effects followed the same pattern for the three oilseed crops. The results showed that sunflower demonstrated a higher environmental load in five of the six categories because of its lower seed yield and higher water and energy demands. The results indicate that production of 1 T of soybean and canola requires 370 and 471 m² of land, respectively. Production of same quantity of sunflower required 426 m² of land. Sunflower required 1.59 and 1.25 times more water than the canola and soybean respectively, to produce the same quantity of oilseed. It was found that the effects from the three crops comes generally from manufactured fertilizer, manure, diesel combustion, agricultural practices, and electricity for irrigation. It can be said that the indirect effects associated with these inputs are related to producing and processing, which had higher impacts than those of the direct effects.