Implementing a life cycle assessment (LCA) to evaluate organic farming weed control and fertilizers environmental implications

Organic farming is expanding globally in response to the growing need for more sustainable food production. However, assessing both direct and indirect environmental effects is essential for identifying effective practices. This paper employs a Life Cycle Assessment (LCA) using a cradle-to-farm gate framework to evaluate the environmental effects of non-chemical weed control methods (row-cultivator, finger-weeding, flaming, and hand-weeding) in combination with four fertilization treatments (compost at 10, 30, and 60 m³ ha^-1, and chemical fertilizer) in the production of four organic field crops grown under irrigated conditions in a Mediterranean climate. The analysis shows that producing 1 kg of crop results in emissions of 0.5-1.6 kg CO₂ eq., 0.002-0.009 kg SO₂, and energy use of 9-37 MJ. Over 95 % of these impacts are driven by irrigation, fertilizers, and weed and pest management. Significant differences between treatments underscore the role of crop-specific farming practices. Finger-weeding consistently lowered environmental impact across most conditions, whereas cultivation and flaming generally resulted in moderate to high impacts regardless of fertilizer level. Hand-weeding had the lowest environmental impact but was the most labor-intensive approach. The untreated control consistently led to the highest environmental burdens, reinforcing the necessity of effective weed management. By identifying key environmental hotspots, this study provides a foundation for optimizing weed control and fertilization strategies, integrating best farming practices, and informing policies to improve the sustainability and resilience of organic cropping systems in Mediterranean agriculture.