Life Cycle Assessment of Irrigated Wheat Production under the Effects of Nitrogen Amounts and Splitting its Use in Boushehr Region

Life cycle assessment is an appropriate method to study the environmental impacts of producing a crop plant throughout its production cycle. This research was conducted with the aim of evaluating the life cycle of irrigated wheat production under nitrogen amounts and splitting in Bushehr province during 2017-18The as split plots based on a randomized complete blocks design with four replications. Four nitrogen rates including 70, 140, 210 and 280 kg urea ha-1 was considered as main plots and three nitrogen splitting in basal, beginning of tillering, stem elongation and booting stages was chosen as sub plot.The results demonstrated that with increase of nitrogen application an amount of cumulative energy demand, cumulative energy demand, acidification, eutrophiction and malodorous air were decreased. The average amount of ecological footprint was 1125.87 m2 per year which CO2 emissions had shown the highest effect on the ecological footprint. The average amount of global warming potential (GWP) was 20a and GWP 500a were 400.53 and 384.30 kg CO2 eq, respectively. All pollutants released into the air and the water experienced a decreasing trend with increasing nitrogen rate. By group comparing between different levels of nitrogen at splitting levels, it can be stated that the main cause of variations in the amount of pollutants was the higher output (yield) compared to inputs. Indeed, nitrogen application in four developmental stages has resulted in maximum plant use, resulting in increased yield and emission reduction per unit area. Therefore, reducing the emission of pollutants by increasing nitrogen consumption can be due to yield increasing.