Introduction: Life cycle assessment (LCA) is an appropriate assessment tool for analyzing crop production scenarios through the identification, quantification, and evaluation of resource consumption and pollutant emissions to the environment. To assess the environmental impacts of four rice production scenarios using the LCA method, resource consumption and pollutant emissions were calculated for Golestan Province in northern Iran.
Materials and methods: To define different rice production scenarios based on conventional and direct-seeding cultivation systems in the study area, long-term data from rice fields were collected for the period from 2015 to 2025. The LCA method was applied to evaluate and compare the performance of different production systems, including TE (transplanted rice production using electricity for irrigation), TD (transplanted rice production using fossil fuel for irrigation), DS (direct-seeded rice production using sprinkler irrigation), and DD (direct-seeded rice production using drip irrigation).
Results: The findings showed that direct-seeded rice production with drip irrigation using polyethylene pipes for one growing season (DD scenario) had the highest values for energy demand (ED), climate change (CC), terrestrial acidification (TA), metal depletion (MD), and agricultural land occupation (ALO). Freshwater eutrophication (FE) was also highest in the DD and TE scenarios (transplanted rice production using electricity for irrigation). The highest marine eutrophication (ME) values were observed in the TE and TD scenarios (transplanted rice production using fossil fuel for irrigation). Water depletion (WD) was highest in the TE scenario. Fossil depletion (FD), terrestrial ecotoxicity (TEc), freshwater ecotoxicity (FEc), and ozone depletion (OD) reached their highest values in the TD scenario. The highest amounts of lead (Pb), cadmium (Cd), mercury (Hg), and zinc (Zn) in air, as well as nickel (Ni) in water, were obtained in the DD scenario. In addition, the highest concentration of Zn in water was observed in the TD scenario. The highest amounts of copper (Cu), Cd, Hg, and Pb in water were observed in the TD and TE scenarios.
Conclusion: Overall, the results indicated that the DS scenario (direct-seeded rice production with sprinkler irrigation) had the lowest environmental impacts among the four rice production scenarios across the assessed impact categories. Therefore, rice production in Golestan Province using the DS scenario can be considered a cleaner production system.