Life cycle assessment (LCA) for a maize production system under Moghan climatic conditions

Life cycle assessment (LCA) is a methodology for measuring the environmental impacts associated with a product, process or activity, by identifying, quantifying and evaluating the resources consumed, along with all emissions and wastes released into the environment. This study examined the environmental impacts for Maize production under Moghan climatic conditions by using LCA methodology. This analysis considered the entire system which was required to produce one ton of maize grain. For this purpose, a functional unit was assumed based on ISO14040 methods which included the extraction of raw materials (e. g. fossil fuels and minerals), the production and transportation of farming inputs (e. g. fertilizers) and all agricultural operations in the field (e. g. tillage and harvest). As a first step, all emissions and the consumption of resources connected to the different processes were listed in a Life Cycle Inventory (LCI) and related to a common unit, namely one ton of grain. Next a Life Cycle Impact Assessment (LCIA) was carried out, in which the inventory data were aggregated into indicators for environmental effects, which included climate change (global warming), acidification and eutrophication (terrestrial and aquatic ecosystems), land use, phosphate resource depletion, potassium resource depletion and water resource depletion. After normalization and weighting of the indicator values it was possible to calculate summarizing indicators for resource depletion and environmental impacts. The values for climate change (global warming), acidification and eutrophication (terrestrial and aquatic ecosystems), land use, phosphate resource depletion, potassium resource depletion and water resource depletion were estimated at 0.04, 0.29, 0.50, 0.11, 0.03, 2.27, 0.75, 0.03 and 0.56, respectively. As a result, among environmental effect categories (EcoX) the highest environmental impacts were observed in the eutrophication (terrestrial) and acidification categories; among the resource depletion categories (RDI), the depletion of fossil resources had the greatest negative environmental impact for maize production in the Moghan region. It seems that management systems based on a low input system, including organic fertilizers and minimum tillage, could be regarded as an alternative management strategy for reducing problematic environmental impacts.