Life cycle assessment of camelina and spelt wheat in organic intercropping systems

Summary

Camelina sativa (L. Crantz) is an annual oilseed crop cultivated for industrial and food purposes. To expand camelina's cultivation area, improve yields, and reduce weed pressure, the crop can be grown in intercropping system. The aim of this study was to evaluate the impact of camelina cultivation in an intercropping system with spelt wheat under organic farming with utilisation of life cycle assessment (LCA). A life cycle assessment for sole cultivation of camelina and spelt was also performed. The system boundary included crop production up to the farm gate, taking into account field emissions and soil organic carbon changes. Due to nearly identical production inputs across all three cropping systems, the environmental impact was similar across all impact categories, with a more noticeable contribution from electricity usage in the intercropping system. Sole camelina cultivation showed a higher impact in 13 impact categories (per 1 Mg functional unit). However, when calculated per 1 GJ, the intercropping system exhibited the highest environmental impact across all categories. Moreover, intercropping resulted in the highest emissions per hectare in the following categories: global warming (860 kg CO₂ eq.), freshwater eutrophication (0.34 kg P eq.), and terrestrial ecotoxicity (2936 kg 1,4-DCB eq.). Our results indicates that intercropping did not reduce the environmental impact compared with sole cropping systems, primarily due to low seed and energy yields per hectare. Nevertheless, the findings demonstrate that both organic intercropping and sole cropping systems have a lower environmental impact than conventional farming systems.