Environmental impacts of fertilization during rice production in saline-alkali paddy fields based on life cycle assessment

While increasing rice yield, the irrational application of nitrogen fertilizers in paddy fields leads to diverse environmental impacts. However, there exists a dearth of comprehensive research systematically addressing these impacts, particularly in areas affected by salinization. This study employs the life cycle assessment (LCA) method to evaluate the environmental impacts of five commonly used fertilizers during rice production in salinealkali paddy fields. Additionally, the economic benefits of these fertilizers were analyzed. Across all treatments, regardless of per unit yield and cultivated area, urea (U) treatment exhibited the highest total environmental impact potential (TEIP) value, while organic-inorganic compound fertilizer (OCF) treatment recorded the lowest. Notably, freshwater eutrophication contributes significantly to TEIP in each treatment compared to other midpoint impacts. For OCF treatment, the negative NEIP values of global warming and stratospheric ozone depletion indicate lower impacts than the other five treatments, respectively. The total endpoint damage potentials of OCF treatment per unit yield and unit area were -75.4331 Pt and -927.8271 Pt, respectively, both lower than the other five treatments. Furthermore, the yield and net income of OCF treatment stands at 12.30 t/ ha and 29691.51 CNY/ha, surpassing all other five treatments. In summary, OCF emerges as an effective nitrogen fertilizer with low input, minimal risk, and substantial benefits when applied to rice production in salinized areas. This study introduces LCA to conduct a comprehensive analysis of rice production in saline-alkali areas, providing essential data for decision-makers to understand the potential environmental impacts of different nitrogen fertilizer applications. By considering various environmental risks and economic benefits simultaneously, this approach offers a methodological framework to support optimized fertilization strategies. This promotes the sustainable development of paddy fields in saline-alkali regions, advancing efficiency and emission reduction practices in rice cultivation.