Hemp seed production: Environmental impacts of Cannabis sativa L. Agronomic practices by life cycle assessment (LCA) and carbon footprint methodologies

Abstract

This paper evaluated the environmental impacts of different agronomic practices for a hemp seed crop grown in Mediterranean environment. The following agricultural variables have been considered: seven monoecious hemp varieties(Epsilon68 (E68), Fedora17 (F17), Felina32 (F32), Ferimon (Fe), Futura75 (F75), Santhica27 (S27), Uso31 (U31), three plant densities (40, 80, and 120 plants m-2), and two levels of nitrogen (N) fertilization (50 and 100 kg ha-1 of N). Life cycle assessment (LCA) and carbon footprint (CF) methodologies have been applied to evaluate impacts. In all hemp genotypes, the impacts grew by decreasing both N fertilizer and plants densities. The scenario most impacting was E68/F75/S27 genotypes cultivated with 50 kg ha-1 of N fertilizer and 40 plants m-2, while the lowest one was Fe with 100 kg ha-1 of N fertilizer and 120 plants m-2. The highest CF was found for E68/F75/S27 cultivated with 50 kg ha-1 of N fertilizer and 40 plants m-2 (18.720 kg CO2 eq). This study highlighted the most environmentally sustainable agronomic practices to support farmer and decision maker in Cannabis sativa L. cultivation for seed production.