Evaluating Environmental Impacts of Corn (Zea mays L.) Agro-ecosystem Using Life Cycle Assessment Method: A Case Study of Grain and Stover Production

Life Cycle Assessment (LCA) is a decision-making tool that assesses the environmental status, production activities, and processes during the useful life of a crop. It should be borne in mind that the LCA uses a variety of techniques for economic, social, and environmental estimates of crops, as well as their activities, processes, and the consumed energy efficiency.The present study evaluates the LCA in corn seed and corn stover production systems in Karaj by the use of two cropping systems: corn produced for seed only, without collecting corn stover (CRN) (seed corn production system) and corn produced to harvest stover (CSR) (corn stover production system). Which were investigated during the years of 2011-2016. Environmental indices were calculated for the CRN and CSR based on six impact categories under Karaj climatic conditions. The highest pollutant index, after resource depletion, was found in acidification impact category (0.90 and 0.34 for the CRN and CSR, respectively), followed by the highest environmental impacts for global warming or climate change impact categories (0.51 and 0.18 for the CRN and CSR, respectively). Therefore, it seems that different methods of farming system management can be utilized based on the use of low-input principles, such as using various organic inputs, planting nitrogen-fixing and perennial plants, the use of crop rotation, utilizing different planting patterns such as intercropping, minimum tillage, and decreased use of chemical inputs, to reduce the environmental impact of this production system, particularly the CRN, on fossil fuel depletion, acidification, and climate change impact categories, thereby reducing the shares of these environmental impacts.