Investigating the Environmental Impacts for Four Varieties of Corn Based on Nitrogen Fertilizer Consumption through Life Cycle Assessment (LCA)

The use of chemical fertilizers has many negative effects on the environment. Therefore, in order to evaluate the environmental effects of four maize cultivars based on the use of nitrogen fertilizer, research was conducted using the life cycle assessment method in Lahijan region.

For this purpose, a field experiment was performed as a split plot in a randomized complete block design with three replications. Treatments were consisted different nitrogen levels (300, 400 and 500 kg/ha urea) as the main plot and four varieties of corn (KSC 647, KSC 700, KSC 704 and Local) as the subplots. In this studysix groups were investigated; the global warming, acidification, terrestrial eutrophication, the depletion of fossil resources, the depletion of potassium and the depletion of phosphate. Production of one ton of corn was considered as a functional unit to evaluate the environmental impacts.

The results showed that maximum environmental index (1.53) and resources depletion index (1.11) was in production of one-ton local variety of corn with treatment 500 kg/ha urea. The minimum environmental index (0.39) and resources depletion index (0.45) was in production of one ton KSC 647 variety of corn with treatment 300 kg/ha urea.

Although there was not a difference between the different treatments of nitrogen in terms of corn yield, but the selection of superior varieties in terms of yield, by reducing nitrogen consumption, reduced damage to the environment.