Evaluation of environmental impacts of saffron (Crocus sativus L.) agroecosystems in the Khorasan province affected as field size by using life cycle assessment

Life cycle assessment (LCA) is a well-known and accurate methodology for comparison of environmental impacts of activities including different agricultural management systems. Since the used inputs have an important role in environmental pollution and greenhouse gas emissions, LCA have been extensively applied for crop species. This study was conducted to assess the environmental impact of saffron production systems based on field area (<0.5, 0.5-1 and >1 ha) in the Khorasan-e Razavi province using LCA methodology. The amounts of utilized agricultural inputs from the first year to the sixth year were collected by means of a questionnaire (13 fields from each area). In this regard, four phases, which are goal and scope definition, inventory analysis, impact assessment and interpretation, were designed to assess life cycle index with ISO14044 procedure. Functional unit were considered as one kg of flower. Three main categories as impacts on environment including global warming, acidification and eutrophication (terrestrial and aquatic) were defined. Finally, an index -called environmental index (EcoX) was calculated. Cronbach's alpha was used assessing the reliability of the questionnaire. The results showed that the Cronbach's alpha was computed with α=%84. The average values for global warming, acidification and eutrophication terrestrial and aquatic categories were calculated with115.41±53.41 kg CO2 equiv. / one kg flower yield, 0.35±0.16 kg SO2 equiv./ one kg flower yield, 0.58±0.27 kg NOx equiv./ one kg flower yield and 0.20±0.09 kg PO4 equiv./ one kg flower yield, respectively. The largest share of greenhouse gas emissions in the global warming category was related to CH4. The maximum emission of pollutants in acidification, eutrophication terrestrial and eutrophication aquatic categories was related to NH3. The results revealed that, field area affected the amounts of utilized agricultural inputs and environmental impacts as flower yield. Eutrophication and climate change categories had more sensitivity and affected as intensification based on field area. Therefore, one of the appropriate approaches to mitigate and decline the environmental impacts of agricultural production is achieving higher economical yield per unit of area by increasing resource use efficiency.