Effect of nitrogen management on the environmental and economic sustainability of wheat production in different climates

Increasing chemical inputs to improve food security has resulted in worrying environmental consequences. Recently, significant efforts have been made to reduce the environmental impacts of the food supply chain. The current study examined the effects of different levels of urea fertilizer on the technical, economic, and envi-ronmental aspects of wheat production in arid and humid climates. A questionnaire was used to collect data on wheat cultivation in the 2019 and 2020 crop seasons. The calibrated and validated AquaCrop model was applied to simulate crop yield under different urea fertilizer levels of 80, 160, and 220 kg ha-1 in arid climate and 100, 180, and 250 kg ha-1 in humid climate. Economic productivity, water productivity, and nitrogen use efficiency indicators was used to assess the economic and technical sustainability of different cropping systems. The environmental impacts was investigated by using the life cycle assessment (LCA) approach involving the ReCiPe 2016 method, covering 18 midpoints and three endpoint indicators, respectively. The most important midpoint categories from foreground-background analysis were global warming, fine particulate matter formation, and terrestrial acidification. Additionally, 75% of the total environmental damage was related to the background system. On average, considering different fertilizer treatments, wheat cultivation in the arid climate had a 9% higher environmental damage potential than the humid climate. Nitrogen played the most significant role in midpoint categories, followed by diesel. The most appropriate urea fertilizer level in the arid climate, compared to the corresponding level in the humid climate, increased human health, ecosystem, and resources by 14.3%, 12.5%, and 3.2%, respectively, and decreased water and economic productivity by 375% and 8%, respectively. Based on the results, combining LCA with technical and economic indicators provides an appropriate method for prioritizing the cultivation of different crops in each county.